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A little bird told me... a funny story of evolution.
#1
[Image: darwin.jpg]

Darwin would love this true story.



Long story short.
Terrible winter across north America...snowmageddon.
Anyways...
We were moving a client out of an apartment building in Moose Jaw ,Saskatchewan and it was damn cold!
As I progressed up and down the ramp during the relocation I noticed something.

It was daylight.
but periodically,the parking lot exterior building light would shine bright amber.

I had experienced 'Street-Light-Interference' (SLI) over my lifetime and didn't even know there was a name for it... so I thought!!!  nah. well maybe... Dunno

Nope.

Something else was going on because it wasn't being caused by my passing under-neath it.

Not exactly "SLI"...yet something was causing this light to periodically light up at daytime.

I had a smoke-break to catch my breath. Reefer
I pondered thye mystery.

Then what did I spy with the corner of my eye?  Damned

Movement.

Movement in the shadows. Hmm2



It was a little bird.

[img]http://upload.wikimedia.org/wikipedia/commons/thumb/a/ae/Darwin's_finches_by_Gould.jpg/220px-Darwin's_finches_by_Gould.jpg[/img]

A little bird behind the metal housing of the golden arc lamp.

I thought:
The bird may have pecked the wires to make a nest and is triggering an electrical short on the yellowish floodlight.
Maybe bird guano is shorting it out.

Just basic elementary Sherlock stuff.

I was wrong.
Right before I finished my cigarette...a second bird alighted on the top of the light,while the first bird was still in the recess/crevice behind the mounting hardware.

A third bird then joined the second to roost on the lightbox.

Lightbulb time...LITERALLY!


Eureka...the physical birds occulted the solar-light sensor.
This tripped the internal switch that triggered arc-lamp on.
THE ARC LAMP CREATED HEAT. Dance2
Viola!  Nice warm birdies!

[Image: swnov04a.jpg]

[move]Adaptive Radiation!!![/move]


I had to have another smoke as I explained to the crew what was happening.
They thought that was a pretty neat trick.

After break and during the duration of the move it became evident this wasn't three birds but more like twenty.

They were trading spaces.
In some informal or possibly a hierarchal pecking order they switched around from the adjacent tree on the grounds and the perch on the top back to the little niche behind the light-housing.

[Image: exterior-lighting-fixture2.jpg]
* exact model not shown or known*

That is what I call advanced tool-use.
I will google street view and map this for the forum because some bird-guy might find this as astonishing behavior.




Along the vines of the Vineyard.
With a forked tongue the snake singsss...
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#2
We Fit Nature to Us: Evolution’s 2-Way Street

By Jag Bhalla |  May 22, 2013 |  Comments3


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It is in our nature to fit nature to us. We are best at it, but other species do it. This obvious but overlooked factor contradicts the dominant one-way-street gene-centric view of adaptation. A better framework for evolution is needed. Its shape isn’t clear, but it must incorporate: extracorporeal gene effects, “gene-culture coevolution,” “niche construction,” reduced randomness, and intelligent influences.

George Williams, a founder of the gene-centric school, claimed “Adaptation is always asymmetrical; organisms adapt to their environment, never vice versa.” He was wrong.

Richard Dawkins proposed the idea of “extended phenotypes”—a phenotype is the subset of an organism’s genetic traits that develop— to describe environmental changes caused by organisms. Derek Bickerton says, for Dawkins a “beaver’s dam [is] just as much an expression of beaver genes” as its tail. But that’s far from the whole tale of gene-environment interactions.

Organisms, and their genes, can face selective pressures from created elements in their environments. Intelligently created nonrandom factors have substantially altered human genes; for example, after only a few thousand years of dairying, adult lactose tolerance has spread to 98% of Swedes but just 7% of Chinese. Protocultural tool use in Galapagos finches has led to their beaks being adapted for using cactus spikes to extract grubs. Unlike Dawkins’s extended phenotypes, this “gene-culture coevolution,” as E. O. Wilson calls it, incorporates more than is in an organism’s genes, accounting for nongenetically transmitted factors like tools, rules, and socially acquired second nature skills.

Niche construction adds to genes and culture a third inheritance process: persisting ecological engineering. Many species inherit niches much modified by their ancestors. To biologists, niches aren’t just physical nooks, they’re entire ways of life. Bickerton defines three elements: habitat, nourishment, and sustaining behaviors, and says “changes in behavior trigger changes in genes at least as often” as the other way around. Evolution’s fitting and matching processes can work both ways, with complex feedback

In Niche Construction: The Neglected Process in Evolution F. John Odling-Smee and colleagues give “hundreds of examples of animal niche construction.” They say it adds nonrandom “directedness to the evolutionary process,” and that neither culture nor intelligence are needed. For example, earthworms “utilize various kinds of niche-construction” to compensate for “bad structural adaptation.” Originally water-worms, they retain ancestral traits by modifying soil to mimic features of their ancestral aquatic conditions. Even changes as radical as moving habitats from water to land can be mitigated by counteractive niche construction.

Darwin said natural selection was “not the exclusive means of modification” in evolution. Ignoring other modifying mechanisms is unnaturally selective. We artificially select factors to which we adapt. As Shakespeare put it “that art Which you say adds to Nature, is an art That Nature makes.” And many creatures are coactive partners in their dance with destiny.

Illustration by Julia Suits, The New Yorker Cartoonist & author of The Extraordinary Catalog of Peculiar Inventions.

http://blogs.scientificamerican.com/gues...ay-street/
Along the vines of the Vineyard.
With a forked tongue the snake singsss...
Reply
#3
[Image: 8796116716_28b0fd50b5_m.jpg]

[Image: 8796118640_8768af23a6_m.jpg]

[Image: 8796132424_4277d5f4d8_m.jpg]
Along the vines of the Vineyard.
With a forked tongue the snake singsss...
Reply
#4
Albeit and granted that there is foilage on the google-earth "Street-View"...

That AIN'T the street-view during snowmageddon!!!




The Birds...

We watched them.

We saw what they were doing.




















They were oblivious to us.








Along the vines of the Vineyard.
With a forked tongue the snake singsss...
Reply
#5
What would Darwin call electrical hardware use... demonstrated by a small flock of birds?

Genus Local Genius?
Dunno
Along the vines of the Vineyard.
With a forked tongue the snake singsss...
Reply
#6
It writes itself...[sub]eh? li'l birdie[/sub]

Quote:Darwin noted that the unique throwing abilities of humans, which were made possible when bipedalism emancipated the arms, enabled foragers to hunt effectively using projectiles3
[Image: artworks-000044323936-i5pdel-original.jpg?ca77017]

Quote:Researchers say ability to throw played a key role in human evolution
June 26, 2013

[Image: 300px-Final-stride-animation.gif]
http://www.wikihow.com/Throw-a-Javelin

[move]Experts recommend 33 degrees as the optimum release angle.[/move]

Watch Video:
http://phys.org/news/2013-06-chimps-huma...tcher.html


[Image: 629px-Throw-a-Javelin-Intro.jpg]

Lift the left leg and move the throwing arm, with the elbow placed high and close to the mid line. The javelin release angle should account for aerodynamic lift and drag. Experts recommend 33 degrees as the optimum release angle.


It's easy to marvel at the athleticism required to throw a 90-mile-per-hour fastball, but when Neil Roach watches baseball, he sees something else at work – evolution.

Quote:That ability – to throw an object with great speed and accuracy – is a uniquely human adaptation, one that Roach believes was crucial in our evolutionary past. How, when and why humans evolved the ability to throw so well is the subject of a study published today (June 26) in the journal Nature. The study was led by Roach, who recently received his Ph.D. from Harvard's Graduate School of Arts and Sciences and is now a postdoctoral researcher at George Washington University, with Madhusudhan Venkadesan of NCBS at the Tata Institute of Fundamental Research, Michael Rainbow of the Spaulding National Running Center, and Daniel Lieberman, the Edwin M. Lerner II Professor of Biological Sciences at Harvard. They found that a suite of changes to our shoulders and arms allowed early humans to more efficiently hunt by throwing projectiles, helping our ancestors become part-time carnivores and paving the way for a host of later adaptations, including increases in brain size and migration out of Africa.


"When we started this research, there were essentially two questions we asked – one of them was why are humans so uniquely good at throwing, while all other creatures including our chimpanzee cousins are not," said Roach. "The other question was: How do we do it? What is it about our body that enables this behavior, and can we identify those changes in the fossil record?"

What they found, Roach said, were a suite of physical changes - such as the lowering and widening of the shoulders, an expansion of the waist, and a twisting of the humerus – that make humans especially good at throwing.

[Image: nature12267-f1.2.jpg]

While some of those changes occurred earlier during human evolution, Lieberman said it wasn't until the appearance of Homo erectus, approximately 2 million years ago, that they all appeared together. The same period is also marked by some of the earliest signs of effective hunting, suggesting that the ability to throw an object very fast and very accurately played a critical role in human's ability to rise to the top of the food chain.

"The ability to throw was one of a handful of changes that enabled us to become carnivores, which then triggered a host of changes that occurred later in our evolution," Lieberman said. "If we were not good at throwing and running and a few other things, we would not have been able to evolve our large brains, and all the cognitive abilities such as language that come with it. If it were not for our ability to throw, we would not be who we are today."

[Image: nature12267-f2.2.jpg]

To start unpacking the evolutionary origins of throwing, Roach began not by studying how humans throw, but how our closest relatives – chimpanzees – do.

Though they're known to throw objects (often feces) underhand, chimps, on rare occasions, do throw overhand, but those throws are far less accurate and powerful than those of the average Little League pitcher, Roach said. Additionally, chimps throw as a part of display behavior and never when hunting.

[Image: nature12267-f3.2.jpg]

Part of the reason for chimpanzee's poor throwing performance, Lieberman said, is tied to their technique, which in turn is limited by their anatomy. "Chimps throw overhand using either a dart throwing motion, where the elbow is extended, or much like a cricket bowler, where their elbow is kept straight and they generate force by swinging their shoulder", Lieberman said.

"That led us to studying cricket bowlers and trying to understand what happens when you keep your arm straight, and why that diminishes your throwing ability," Roach said. "Eventually, we began to think that changes in the way the shoulder is oriented with regards to the rest of the body could change the way you generate force when you're throwing."

To explore those physical changes, Roach and colleagues began by creating a complex model that incorporated current research about the biomechanics of throwing. Using that model, they were able to explore how morphological changes to the body – wider shoulders, arms that are higher or lower on the body, the ability to twist the upper body independently of the hips and legs, and the anatomy of the humerus – effect throwing performance.

In addition to the modeling, Roach performed a series of real-world experiments in Lieberman's Skeletal Biology Lab using members of the Harvard Baseball team and a host of braces designed to limit their movements.

The idea, Roach explained, was that by restricting certain motions, the players would be forced into a more primitive condition, giving him the opportunity to see how different anatomical shifts contribute to the mechanics of modern throwing.

Armed with a method known as inverse dynamics, Roach and colleagues were able to not only quantify how much restricting certain types of movements affected throwing performance, but were able to trace the effect to specific changes in the mechanics of each player.

"We try to push these bits of anatomy back in time, if you will, to see how that affects performance," Roach said. "The important thing about our experiments is that they went beyond just being able to measure how the restriction affects someone's ability to throw fast and accurately – they allowed us to to figure out the underlying physics. For example, when a thrower's velocity dropped by 10 percent, we could trace that change back to where it occurred."

"In order to test our evolutionary hypotheses, we needed to link the changes we'd seen in the fossil record to performance in terms of throwing," he continued. "This type of analysis allowed us to do that."

Nature | Letter
Elastic energy storage in the shoulder and the evolution of high-speed throwing in homo Neil T. Roach,1, 2 Madhusudhan Venkadesan,3 Michael J. Rainbow4 & Daniel E. Lieberman1
AffiliationsContributionsCorresponding author Journal name:
Nature
Volume:
498,
Pages:
483–486
Date published:
(27 June 2013)DOI:
doi:10.1038/nature12267
Received11 January 2013 Accepted02 May 2013 Published online26 June 2013 Article

Some primates, including chimpanzees, throw objects occasionally1, 2, but only humans regularly throw projectiles with high speed and accuracy. Darwin noted that the unique throwing abilities of humans, which were made possible when bipedalism emancipated the arms, enabled foragers to hunt effectively using projectiles3. However, there has been little consideration of the evolution of throwing in the years since Darwin made his observations, in part because of a lack of evidence of when, how and why hominins evolved the ability to generate high-speed throws4, 5, 6, 7, 8. Here we use experimental studies of humans throwing projectiles to show that our throwing capabilities largely result from several derived anatomical features that enable elastic energy storage and release at the shoulder. These features first appear together approximately 2?million years ago in the species Homo erectus. Taking into consideration archaeological evidence suggesting that hunting activity intensified around this time9, we conclude that selection for throwing as a means to hunt probably had an important role in the evolution of the genus Homo.
Subject terms:Biological anthropology Musculoskeletal system Biological physics Palaeontology

[Image: nature12267-f4.2.jpg]

What they found were three key physical changes that helped to make fast, accurate throwing possible.

Evolutionary changes in the shoulder show that, as a pitcher cocks their arm back, "what they're doing is stretching the ligaments and tendons that run across their shoulder," Roach said. "Those tendons and ligaments get loaded up like the elastic bands on a slingshot, and late in the throw they release that energy rapidly and forcefully to rotate the upper arm with extraordinary speed and force." That rotation is the fastest motion the human body can produce. "The rotation of the humerus can reach up to 9,000 degrees-per-second, which generates an incredible amount of energy, causing you to rapidly extend your elbow, producing a very fast throw", Roach said.

Among the evolutionary changes that proved key to generating a powerful throwing motions, he said, was a twist in the bone of the upper arm and an expanded, mobile waist, which both gave early humans the ability to store up and then release more of this elastic energy

"The linchpin is really what's going on with the shoulder," Roach said. "When you see the shift from a chimpanzee shoulder to a more relaxed human-like shoulder, that enables this massive energy storage. Many of the evolutionary changes we studied, whether in the torso or the wrist, may predate Homo erectus, but when we see that final change in the shoulder, that's what brings it all together."

While the findings help shed light on a critical phase of human evolution, they also hint at a possible solution to a hotly debated question in sports: When it comes to young players, how much throwing is too much?

"It's a tough question to answer," Roach said. "The real difference, from an evolutionary perspective, is the frequency with which some folks throw now. To successfully learn to throw and use that ability to hunt, our ancestors would need to throw often, but nothing like the 100 or more high speed throws that some baseball pitchers throw now in the span of a couple of hours."

"I think it's really a case of what we evolved to do being superseded by what we're now asking athletes to do," he continued. "Athletes are overusing this capability that gave early humans an evolutionary advantage, and they're overusing it to the point that injuries are common."

Ultimately, Lieberman said, the evidence points to one clear conclusion – the ability to throw with speed and accuracy is a uniquely human adaptation, one that played an immeasurably important role in human development.

"Recent research indicates that stone points – the oldest kind of spear point – are about 500,000 years old," he said. "But people have been killing animals for at least 2 million years, and eating animals for about 2.6 million years."

"That means that for about 1.5 million years, when people hunted, they basically had nothing more lethal to throw than a pointed wooden stick," he continued. "If you want to kill something with that, you have to be able to throw that pretty hard, and you have to be accurate. Imagine how important it must have been to our ancestors to throw hard and fast."

http://phys.org/news/2013-06-chimps-huma...tcher.html

More information: Paper: dx.doi.org/10.1038/nature12267

http://www.nature.com/nature/journal/v49...12267.html


Journal reference: Nature





[Image: heroes_of_newerth___zeus_by_izaskun-d5zo4rj.jpg]
Experts(Zeus) recommend [glow=red,2,300]33[/glow] degrees as the optimum release angle.

Along the vines of the Vineyard.
With a forked tongue the snake singsss...
Reply
#7
holey Geospiz fortis,   initiating a new lineage.
"The novelty of this study is that we can follow the emergence of new species in the wild,"
Fresh BirdSeeds Geospiza conirostris   Banana_hump  G. fortis Galapagos


Quote:In 1981, a graduate student working with the Grants on Daphne Major noticed the newcomer, a male that sang an unusual song and was much larger in body and beak size than the three resident species of birds on the island.

Recall: Yesterbird.


Quote:Lightbulb time...LITERALLY!



Eureka...the physical birds occulted the solar-light sensor.
This tripped the internal switch that triggered arc-lamp on.
THE ARC LAMP CREATED HEAT. [Image: dance2.gif]
[Image: 12_Turkey-108950.jpg]Adaptive Radiation!!!
Viola!  Nice warm birdies!

[Image: swnov04a.jpg]

Adaptive Radiation!!!


Galapagos study finds that new species can develop in as little as two generations

November 23, 2017


[Image: galapagosstu.jpg]
The breeding of two distinct parent species gave rise to a new lineage (termed "Big Bird" by the researchers). This lineage has been determined to be a new species. This image is of a member of the Big Bird lineage. Credit: Copyright P. R. Grant
The arrival 36 years ago of a strange bird to a remote island in the Galapagos archipelago has provided direct genetic evidence of a novel way in which new species arise.


In this week's issue of the journal Science, researchers from Princeton University and Uppsala University in Sweden report that the newcomer belonging to one species mated with a member of another species resident on the island, giving rise to a new species that today consists of roughly 30 individuals.
The study comes from work conducted on Darwin's finches, which live on the Galapagos Islands in the Pacific Ocean. The remote location has enabled researchers to study the evolution of biodiversity due to natural selection.
The direct observation of the origin of this new species occurred during field work carried out over the last four decades by B. Rosemary and Peter Grant, two scientists from Princeton, on the small island of Daphne Major.
"The novelty of this study is that we can follow the emergence of new species in the wild," said B. Rosemary Grant, a senior research biologist, emeritus, and a senior biologist in the Department of Ecology and Evolutionary Biology. "Through our work on Daphne Major, we were able to observe the pairing up of two birds from different species and then follow what happened to see how speciation occurred."
In 1981, a graduate student working with the Grants on Daphne Major noticed the newcomer, a male that sang an unusual song and was much larger in body and beak size than the three resident species of birds on the island.
[Image: 1-galapagosstu.jpg]
The bird is a member of the G. fortis species, one of two species that interbred to give rise to the Big Bird lineage. Credit: Copyright B.R. Grant
"We didn't see him fly in from over the sea, but we noticed him shortly after he arrived. He was so different from the other birds that we knew he did not hatch from an egg on Daphne Major," said Peter Grant, the Class of 1877 Professor of Zoology, Emeritus, and a professor of ecology and evolutionary biology, emeritus.
The researchers took a blood sample and released the bird, which later bred with a resident medium ground finch of the species Geospiz fortis, initiating a new lineage. The Grants and their research team followed the new "Big Bird lineage" for six generations, taking blood samples for use in genetic analysis.
In the current study, researchers from Uppsala University analyzed DNA collected from the parent birds and their offspring over the years. The investigators discovered that the original male parent was a large cactus finch of the species Geospiza conirostris from Española island, which is more than 100 kilometers (about 62 miles) to the southeast in the archipelago.


Read more at: https://phys.org/news/2017-11-galapagos-...s.html#jCp

[/url]The remarkable distance meant that the male finch was not able to return home to mate with a member of his own species and so chose a mate from among the three species already on Daphne Major. This reproductive isolation is considered a critical step in the development of a new species when two separate species interbreed.
The offspring were also reproductively isolated because their song, which is used to attract mates, was unusual and failed to attract females from the resident species. The offspring also differed from the resident species in beak size and shape, which is a major cue for mate choice. As a result, the offspring mated with members of their own lineage, strengthening the development of the new species.
Researchers previously assumed that the formation of a [url=https://phys.org/tags/new+species/]new species
takes a very long time, but in the Big Bird lineage it happened in just two generations, according to observations made by the Grants in the field in combination with the genetic studies.
[Image: 2-galapagosstu.jpg]
A member of the G. conirostris species, this bird flew from roughly 100 kilometers away to establish a new home on the Galapagos island of Daphne Major. There, the bird mated with a member of the G. fortis species to give rise to the Big Bird lineage. Credit: Copyright B. R. Grant
All 18 species of Darwin's finches derived from a single ancestral species that colonized the Galápagos about one to two million years ago. The finches have since diversified into different species, and changes in beak shape and size have allowed different species to utilize different food sources on the Galápagos. A critical requirement for speciation to occur through hybridization of two distinct species is that the new lineage must be ecologically competitive—that is, good at competing for food and other resources with the other species—and this has been the case for the Big Bird lineage.
"It is very striking that when we compare the size and shape of the Big Bird beaks with the beak morphologies of the other three species inhabiting Daphne Major, the Big Birds occupy their own niche in the beak morphology space," said Sangeet Lamichhaney, a postdoctoral fellow at Harvard University and the first author on the study. "Thus, the combination of gene variants contributed from the two interbreeding species in combination with natural selection led to the evolution of a beak morphology that was competitive and unique."
The definition of a species has traditionally included the inability to produce fully fertile progeny from interbreeding species, as is the case for the horse and the donkey, for example. However, in recent years it has become clear that some closely related species, which normally avoid breeding with each other, do indeed produce offspring that can pass genes to subsequent generations. The authors of the study have previously reported that there has been a considerable amount of gene flow among species of Darwin's finches over the last several thousands of years.
One of the most striking aspects of this study is that hybridization between two distinct species led to the development of a new lineage that after only two generations behaved as any other species of Darwin's finches, explained Leif Andersson, a professor at Uppsala University who is also affiliated with the Swedish University of Agricultural Sciences and Texas A&M University. "A naturalist who came to Daphne Major without knowing that this lineage arose very recently would have recognized this lineage as one of the four species on the island. This clearly demonstrates the value of long-running field studies," he said.
It is likely that new lineages like the Big Birds have originated many times during the evolution of Darwin's finches, according to the authors. The majority of these lineages have gone extinct but some may have led to the evolution of contemporary species. "We have no indication about the long-term survival of the Big Bird lineage, but it has the potential to become a success, and it provides a beautiful example of one way in which speciation occurs," said Andersson. "Charles Darwin would have been excited to read this paper."
[Image: 1x1.gif] Explore further: A gene that shaped the evolution of Darwin's finches
More information: "Rapid hybrid speciation in Darwin's finches" Science (2017). science.sciencemag.org/lookup/ … 1126/science.aao4593

Journal reference: Science [Image: img-dot.gif] [Image: img-dot.gif]
Provided by: Princeton University


Read more at: https://phys.org/news/2017-11-galapagos-...s.html#jCp
Reply
#8
Got into a discussion with a fellow about Noah's Ark being able to hold all the animals needed to repopulate the earth after the Great Flood of Biblical fame.
He pointed out rightly, that there were millions and millions of species of creatures (by any reckoning) prior to the Great Flood, and that all of them could not have fit in a barge of even so great dimensions.

He read the description of how the Ark was populated to 'Prove' his point.
But he over looked one important point.
The bible states that certain numbers of 'Kind' were to be taken into the Ark, not 'Species'.
A Blacktail, a White Tail, A mule Deer, a Caribou, an Elk, and a Moose. 6 different species, but all one kind (family), All are members of the DEER Family (Kind)
A mouse, a bat, a rat, and a Squirrel. 4 different species, but all rodents.
I suppose you could cross a bat and a mouse by interbreeding, and make a new species?
I suppose you could cross a horse and a deer genetically, and end up with a new species? But I wonder if the dominate species would not continue to be the 'Kind'?
I have heard of genetic experiments crossing a flower/firefly to produce a plant that glows in the dark.
What then would that be?

There is great argument about Kind not being a scientific phrase, but if you have a group of fish, and a group of canine, and then a virus, then birds...'Kind' seems to break down both similarities and differences quite effectively. Kind and Species categorize into those areas quite nicely.
So, the words Autumn and Fall are not to be capitalized?
They are in my world!

What has been is what will be, and what has been done is what will be done; and there is nothing new under the sun.
Is there a thing of which it is said, "See, this is new?"It has been already, in the ages before us. Ecc 1: 9-10
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#9
6,000-year-old monument offers a tantalizing glimpse of Britain’s neolithic civilization

November 20, 2017 

[Image: file-20171118-11436-1t8gdcr.jpg?ixlib=rb...6&fit=clip]
Cat’s Brain long barrow is near the more famous Stonehenge (pictured) but predates it by hundreds of years. Shutterstock

This summer, the University of Reading Archaeology Field School excavated one of the most extraordinary sites we have ever had the pleasure of investigating. The site is an Early Neolithic long barrow known as “Cat’s Brain” and is likely to date to around 3,800BC. It lies in the heart of the lush Vale of Pewsey in Wiltshire, UK, halfway between the iconic monuments of Stonehenge and Avebury.

It has long been assumed that Neolithic long barrows are funerary monuments; often described as “houses of the dead” due to their similarity in shape to long houses. But the limited evidence for human remains from many of these monuments calls this interpretation into question, and suggests that there is still much to be learnt about them.

[Image: file-20171118-11473-1e7ewzf.jpg?ixlib=rb...4&fit=clip]
‘Cat’s Brain’. Adam Stanford., Author provided (No reuse) 

In fact, by referring to them as long barrows we may well be missing the main point. To illustrate this, our excavations at Cat’s Brain failed to find any human remains, and instead of a tomb they revealed a timber hall, suggesting that it was very much a “house for the living”. This provides an interesting opportunity to rethink these famous monuments.
The timber hall at Cat’s Brain was surprisingly large, measuring almost 20 metres long and ten metres wide at the front. It was built using posts and beamslots, and some of these timbers were colossal with deep cut foundation trenches, so that it’s general appearance is of a robust building with space for considerable numbers of people. The beamslots along the front of the building are substantially deeper than the others, suggesting that its frontage may have been impressively large, monumental in fact, and a break halfway along this line indicates the entrance way.
An ancient ‘House Lannister’?
Timber halls such as these are an aspect of the earliest stages of the Neolithic period in Britain, and there seems little doubt that they were created by early pioneer Neolithic people. Frequently, they appear to have lasted only two or three generations before being deliberately destroyed or abandoned. These houses need not be dwellings, however, and given their size could have acted as large communal gathering places.

[Image: file-20171118-11436-8cqlg0.JPG?ixlib=rb-...4&fit=clip]
The outline of the ‘house’. Andy Burns, Author provided (No reuse) 

It is worth briefly pausing here and thinking of the image of a house – for the word “house” is often used as a metaphor for a wider social group (think of the House of York or Windsor, or – if you’re a Game of Thrones fan like me – House Lannister or House Tyrell).
In this sense, these large timber halls could symbolise a collective identity, and their construction a mechanism through which the pioneering community first established that identity. We may imagine a variety of functions for this building, too, none of which are mutually exclusive: ceremonial houses or dwellings for the ancestors, for example, or storehouses for sacred heirlooms.
From this perspective, it is not a huge leap of the imagination to see them as containing, among other things, human remains. This does not make them funerary monuments, any more than churches represent funerary monuments to our community. They were not set apart and divided from buildings for the living, but represented a combination of the two – houses of the living in a world saturated with, and inseparable from, the ancestors.
These houses would have been replete with symbolism and meaning, and charged with spiritual energy; even the process of building them is likely to have taken on profound significance. In this light, then, it is interesting to note that towards the end of our excavations this summer, just as we were winding up, we uncovered two decorated chalk blocks that had been deposited into a posthole during the construction of the timber hall.
The decoration on these blocks comprises deliberately created depressions and incised lines, which have wider parallels at other early Neolithic sites, such as the flint mines of Sussex.

[Image: file-20171118-11439-vf1jyd.jpg?ixlib=rb-...4&fit=clip]
The marked chalk blocks. University of Reading, Author provided 

Controversy often surrounds decorated chalk pieces; chalk is soft and easily marked and some people suggest that they are “decorated” with nothing more than the scratchings of badgers. But there is no doubt that the Cat’s Brain marks are human workmanship and the discovery should spark a fresh investigation into decorated chalk plaques more widely.
Imbued with power
For the moment, the original purpose of the carvings remains obscure, but clearly they were of significance. They will have had meaning and potency to the people that created them, and by depositing them in a posthole the building itself may have been imbued with that power, as well as marking it with individual or community identity. The discovery adds to the way we understand these monuments and weight to the argument that these buildings represent more than just “houses of the dead”.
Over time, deep ditches were dug either side of the timber hall at Cat’s Brain and the quarried chalk may have been piled over the crumbling building after it had gone out of use, closing it down and transforming the house from a wooden structure into a permanent earthen monument; the shape and symbolism of which will have been known to all who saw it. With this transformation, the identity of this early Neolithic group was finally and permanently inscribed upon the landscape.
Now, with this investigation, we have been granted a glimpse of the lives and beliefs of our ancestors nearly 6,000 years ago.

The excavations at Cat’s Brain, including the decorated chalk blocks, will feature on Digging for Britain, to be screened on BBC4, at 9pm on Wednesday November 22. Source: https://theconversation.com/6-000-year-o...tion-87730

Bob... Ninja [Image: 209.gif]
"The Light" - Jefferson Starship-Windows of Heaven Album
I'm an Earthling with a Martian Soul wanting to go Home.   
You have to turn your own lightbulb on. ©stevo25 & rhw007
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#10

Researchers describe first-ever hybrid bird species from the Amazon

December 25, 2017, University of Toronto


[Image: 199-researchersd.jpg]
The male golden-crowned manakin has evolved yellow feathers, likely as a way to attract potential female mates. Credit: University of Toronto Scarborough
A team of U of T Scarborough researchers have described the first known hybrid bird species to be found in the Amazon rainforest.

Through a series of genetic and other tests the team have revealed that the golden-crowned manakin - first discovered in Brazil in 1957 but not seen again until 2002 - is in fact a hybrid species.

"While hybrid plant species are very common, hybrid species among vertebrates are exceedingly rare," says Associate Professor Jason Weir, senior author of the research.

A hybrid species forms when two parental species mate to produce a hybrid population, which then stops being able to freely interbreed with the parental species. In this case the two parents are the snow-capped manakin, named for its bright snowy-white crown feathers, and the opal-crowned manakin, named for its brilliant iridescent crown feathers.

Weir and his team, which included lead author and former graduate student Alfredo Barrera-Guzman, gathered genetic and feather samples over two separate field trips to Brazil. They were then able to sequence a large portion of the golden-crowned manakin's genome including 16,000 different genetic markers, finding that about 20 per cent of its genome came from the snowy-crowned, and about 80 per cent came from the opal-crowned.

The researchers also used something called coalescent modelling to figure out at what point the golden-crowned split off from its parental species. They determined it was around 180,000 years ago when the two parental species originally mated, and that both parental species diverged from a common ancestor about 300,000 years ago, making all three very recent birds by Amazon rainforest standards.

"Most Amazon bird species diverged from their most recent relative around 1.5 to 4 million years ago, so these are all young birds by comparison" says Weir, an expert on the biodiversity of New World birds.

The male golden-crowned has unique yellow crown feathers that are much duller than its parental species. To learn more about this unusual characteristic, the researchers took a closer look at the keratin structure of the crown feathers of all three bird species using an electron microscope. The two parent species each have very different structural arrangements of the keratin, which is responsible for creating the highly reflective colours that help males show-off to females in the dark rainforest interior. In the case of the golden-crowned, they discovered it had a mix of keratin structures from both parental species.


"The golden-crowned manakin ended up with an intermediate keratin structure that does a poor job of making either the brilliant white or the reflective iridescence of the parental species," says Weir.
The golden-crowned manakin likely had duller white or grey feathers early on in its existence as a result of its keratin structure, but eventually evolved yellow feathers as an alternative way to attract females. The end result is a uniquely coloured species.
The golden-crowned manakin lives in an area of the south-central Amazon Rainforest that is approximately 200 sq. km and is largely separated from areas where snow-capped and opal-crowned live by wide rivers that the birds are reluctant to cross. As Weir points out, it likely owes its survival as a species on being geographically isolated from its parental species at some point during a past ice age when rainforest coverage contracted, and wide rivers formed natural barriers.
"Without geographic isolation, it's very likely this would never have happened because you don't see the hybrids evolving as separate species in other areas where both parental species meet."
There are some potential candidates of hybrid species in nature, like the red wolf of eastern North America, possibly a hybrid between the coyote and grey wolf. And while hybrids of two species do occur in nature, as Weir notes in most cases they won't develop unique characteristics to become its own separate species.
"This is what makes the golden-crowned manakin such a novel animal," he says.
The research, which will be published in the Proceedings of the National Academy of Science (PNAS).
[Image: 1x1.gif] Explore further: Sparrow chicks can ID song from opening note
More information: Alfredo O. Barrera-Guzmán el al., "Hybrid speciation leads to novel male secondary sexual ornamentation of an Amazonian bird," PNAS (2017). www.pnas.org/cgi/doi/10.1073/pnas.1717319115





Read more at: https://phys.org/news/2017-12-first-ever...n.html#jCp

[/url]


A classic Darwinian ecological hypothesis holds up—with a twist

December 25, 2017,
University of Colorado at Boulder


[Image: charlesdarwin.jpg]
Credit: CC0 Public Domain
New University of Colorado Boulder-led research shows that a long-held hypothesis about the factors that govern species ranges largely holds true, but may be the result of a previously underappreciated ecological mechanism.


The prediction, first iterated by Charles Darwin in 1859, holds that climate factors will limit species expansion in more stressful environments (such as cold or dry regions), but that interactions with other species, like competition and pollination, will limit a species range in less stressful environments, where the climate is more temperate.
The new CU Boulder study, published today in the journal Proceedings of the National Academy of Sciences, finds that while the broad outline of Darwin's hypothesis holds true—the effects of species interactions on a specific plant population increased in conjunction with decreasing environmental stress—there is a nuance to the commonly held model.
"Darwin and others have said that what drives this pattern is gradients in density or diversity of interacting species, but instead it seems to be effects of stress on growth, survival, reproduction and germination of the plant species," said Allison Louthan, who led the research while completing her PhD dissertation in CU Boulder's Environmental Studies Program.
At three field sites in central Kenya that varied in overall aridity, the researchers studied the population dynamics of Hibiscus meyeri, a common flowering plant, over a period of four years. The ubiquity of this particular flowering species, Louthan said, makes it a useful model system for studying differences in population dynamics across an ecological gradient.
As expected, pollination, herbivory and competition with other herbs and shrubs played a strong role in setting the edges of the plant's range in the wetter sites. Those same interactions, however, did not seem to have a strong hand in H. meyeri's expansion to drier sites.
"This research provides a guide about where and when species interactions are important and where they are less important," said Louthan, now a post-doctoral researcher at Duke University. "Understanding the different forces that set limits to a species range and allow populations to expand or contract is crucial for understanding both ecological and evolutionary dynamics."
Next, the researchers plan to expand their experimental method to other systems, in order to continue studying how a species reacts to various factors across a broad geographic area.
"Even before climate change, a major question was why species have the range limits that they do, and what the importance was of climate versus interactions with other species in setting these limits," said Dan Doak, a professor in CU Boulder's Environmental Studies Program and a coauthor on the study. "Now, with ongoing climate change, these questions are much more pressing. This work shows that multiple forces matter in shaping where a species lives and also that the mechanisms driving these effects are not what biologists have usually assumed."
[Image: 1x1.gif] Explore further: Sub-tropical corals vulnerable, new study shows
More information: Allison M. Louthan el al., "Aridity weakens population-level effects of multiple species interactions on Hibiscus meyeri," PNAS (2017). www.pnas.org/cgi/doi/10.1073/pnas.1708436115

Journal reference: Proceedings of the National Academy of Sciences [Image: img-dot.gif] [Image: img-dot.gif]
Provided by: University of Colorado at Boulder


Read more at: https://phys.org/news/2017-12-classic-da...h.html#jCp




Social interactions override genetics when birds learn new songs

December 26, 2017 by Nicholas Weiler, University of California, San Francisco


[Image: 1-socialintera.jpg]
Bengalese finches. Credit: Brainard lab / UCSF
New UC San Francisco research finds that although young male songbirds are genetically predisposed to sound like their fathers, enriched early experience with a foster-father can overcome this genetic destiny. This finding has striking implications for our thinking about how experience influences the genetics of complex human traits like learning ability or even psychiatric disease, the authors say.

Neuroscientists like UCSF's Michael Brainard, Ph.D., have long studied songbirds like the Bengalese finch (Lonchura striata domestica) as a model of how complex behaviors like human language are shaped by early experience. Like human language, a male finch's unique mating song is learned early in life by listening to and mimicking adult "tutors." In nature, this is usually the bird's father, but young birds raised by unrelated adults in the lab will learn to sing their foster-father's song instead.

Now Brainard's lab has shown that not all early experiences are equal in their influence over impressionable young birds: exposed only to a computerized "synthetic tutor," young birds will revert to singing like a biological father they've never known or heard. The research—published the week of December 25, 2017 in PNAS—suggests that finch song has a stronger genetic component than had previously been realized, but also that this genetic drive can be suppressed by the right kind of early life experience.

"What we saw is that the genetic contribution to a bird's song depends on the specifics of that bird's experience. This is a striking demonstration that heritability for complex behaviors like birdsong is not fixed, as is often assumed, but instead can vary dramatically depending on the experience of an individual," said Brainard, a professor of physiology and of psychiatry at UCSF, Howard Hughes Medical Institute investigator, and member of the UCSF Weill Institute for Neurosciences.

As noted, researchers have long considered the structure of adult birdsong to be dominated by the influence of whatever song a bird hears as a chick. However, David Mets, Ph.D., a postdoctoral scholar in the Brainard lab and the new paper's first author, noticed a surprising amount of variation between the songs of individual Bengalese finches in the lab, even when all birds were exposed to the same experimentally controlled tutor song early in life.

To determine whether these differences might be caused by a previously overlooked genetic contribution to the birds' song, Mets developed a careful set of experiments to control the contribution of genetics and experience. He removed eggs from their nests shortly after they were laid to ensure chicks never heard their fathers' song, even in the egg. He then exposed the hatchlings only to carefully controlled computer-generated songs, which he varied in tempo in an attempt to influence the tempo of the song the young birds would learn.


To the researchers' surprise, they found that these birds largely ignored the tempo of the synthetic songs, and developed adult songs with tempos much closer to their fathers' songs—which they had never heard. The researchers quantified this observation, showing that 55 percent of variability in the experimental birds' songs could be explained by differences in their fathers' songs, but only 21 percent was driven by differences in the synthetic song they heard as chicks.
In a second set of experiments, Mets got rid of the synthetic tutor and instead exposed finch chicks—which also had never heard their fathers' songs—to unrelated live adult males. The researchers were again surprised to discover a complete reversal of the results seen with synthetic tutoring: the live tutor's song contributed 53 percent to the tempo of the young birds' adult songs, with differences in their fathers' songs contributing only 16 percent.
"This was really exciting because it showed that the experience provided by a live tutor can actually reduce the contribution of genetics to complex behavior like birdsong," Mets said. "We knew before that live tutors helped birds learn better and faster, but we were surprised to find that this experience can actually override the bird's genetics."
"We've gotten used to the idea that complex traits and behaviors can have a big genetic component," Brainard added, citing human studies of identical twins separated at birth who nonetheless share surprising similarities in things like their sense of humor, fashion sense, and so on. "But those stories tend to assume that the genetic component is fixed—academic achievement is either 20 percent genetic or 80 percent genetic. We're showing here that the contribution of genetics is anything but fixed—in the case of academic achievement, the school you go to may well overcome any contribution of genetics."
The findings raise the possibility that human genetic studies that fail to account for differences in individuals' experience could be producing misleading conclusions about the genetic contributions to complex behaviors, Brainard said.
The researchers now hope to use the Bengalese finch as a model to explore how genetics and experience interact in the brain to influence complex behaviors like birdsong. "Where in the brain are the father's genes and early life experience competing for control over song tempo?" Mets asked. "That's the next really exciting question."
The results also suggest a broader opportunity to understand the specific features of enriched early experiences that allows them to override genetic predispositions, Brainard said: "This is far into the future, of course, but it highlights the potential of early behavioral intervention to help mitigate negative genetic traits, such as a predisposition to psychiatric disease."
[Image: 1x1.gif] Explore further: Two brain regions interact to help finches know when and how to tailor their songs for specific situations
More information: David G. Mets el al., "Genetic variation interacts with experience to determine interindividual differences in learned song," PNAS (2017). www.pnas.org/cgi/doi/10.1073/pnas.1713031115

Journal reference: Proceedings of the National Academy of Sciences [Image: img-dot.gif] [Image: img-dot.gif]
Provided by: University of California, San Francisco


Read more at: https://phys.org/news/2017-12-social-int...s.html#jCp



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Along the vines of the Vineyard.
With a forked tongue the snake singsss...
Reply
#11
I read once that they had discovered that homing pigeons were using the Motorway system in the UK to navigate by.
Reply
#12
Quote:Posted by The Watcher - Tuesday, December 26th, 2017, 06:33 pm I read once that they had discovered that homing pigeons were using the Motorway system in the UK to navigate by.

...makes common sense to me.

Another common route Arrow 
Recall:

Quote:Wednesday, May 22nd, 2013, 10:37 pm  

We Fit Nature to Us: Evolution's a 2-Way Street

By Jag Bhalla |  May 22, 2013
It is in our nature to fit nature to us. We are best at it, but other species do it. This obvious but overlooked factor contradicts the dominant one-way-street gene-centric view of adaptation. A better framework for evolution is needed. Its shape isn'€™t clear, but it must incorporate: extracorporeal gene effects, €œgene-culture coevolution,niche construction, reduced randomness, and intelligent influences.


All roads lead to Rome...
Itza not our destination.

Wrens' calls reveal subtle differences between subspecies
December 27, 2017, American Ornithological Society


[Image: wrenscallsre.jpg]
Biologist Sarah Luttrell captures a recording of a Marsh Wren's calls. Credit: S. Luttrell
Birds' songs and the ways they vary between places have been well studied—but what can the simpler vocalizations known as calls tell us about bird biology? A new study from The Auk: Ornithological Advances provides the first detailed description of how Marsh Wren calls vary across eastern North America and hints at the evolutionary processes playing out between wren subspecies.


Read more at: https://phys.org/news/2017-12-wrens-reve...s.html#jCp


Computational study of world music outliers reveals countries with distinct recordings
December 21, 2017, Queen Mary, University of London


[Image: 578650fe544c4.jpg]
Credit: CC0 Public Domain
Botswana is the country with the most distinct musical recordings around the world while China has the most distinct recordings in relation to its neighbours, according to research by Queen Mary University of London.


Read more at: https://phys.org/news/2017-12-world-musi...s.html#jCp



Birdsong  Sheep   Music

Loco  Sheep  Lingo

Galapagos to UK




play both vids simultaneously to hear a caw-caw-funny.

Dictionary


ca·coph·o·ny
kəˈkäfənē/
noun
noun: cacophony; plural noun: cacophonies
  1. a harsh, discordant mixture of sounds.
    "a cacophony of deafening alarm bells"
    synonyms:
    din, racket, noise, clamor, discord, dissonance, discordance, uproar
    "despite the cacophony, Rita slept on"

Origin
Along the vines of the Vineyard.
With a forked tongue the snake singsss...
Reply
#13
...
Fascinating material on birds!

One thing of note I have seen recently in this very cold weather here,
was highly organized crow behavior.
I have been putting seed out for the birds during the day,
because it is so cold and barren right now.

I noticed a crow fly up on to the apple tree,
look at me and caw twice,
with an inquisitive look on it's face.

I assumed that he wanted to eat some seed variety.
So, walking away from the front of the house for less than a minute, 
and thus out of sight of the crow,
for something in the storage shed,
I came back around to the home front,
and there were about 6-8 crows,
buzzing about the outdoor trash cans that had garbage sealed inside.
They were searching for an open lid.

The first crow that I had seen earlier, before the whole group arrived,
-- was the sentry and advance lookout --

They moved in fast on to the garbage cans as I went out of sight,
andf left just as quickly when I arrived back.

The organized crow packs are impressive.
...
Reply
#14
Evolved illusion—blackest black gives bird of paradise an edge
January 10, 2018 by Bill Hathaway, Yale University


[Image: evolvedillus.jpg]
Credit: Ed Scholes
The mating display of the male bird of paradise owes its optical extravagance to a background so black it is the envy of telescope and solar panel engineers, according to a new study published Jan. 9 in the journal Nature Communications.

Their velvety black plumage is so dark it gives the illusion that adjacent patterns of color glow brilliantly, an effect much appreciated by mate-hunting females, according to the researchers. Optical measurements showed that these feather patches absorb up to 99.95 percent of directly incident light, a percentage comparable to manmade ultra-black materials used in the lining of space telescopes. Microscopic structures of the wings even resemble those designed by engineers to create ultra-black materials used to facilitate light absorption in solar panels.
"Evolution sometimes ends up with the same solutions as humans," said senior author Rick Prum, the William Robertson Coe Professor of Ornithology of Ecology and Evolutionary Biology at Yale.
The juxtaposition of darkest black and colors create to bird and human eyes what is essentially an evolved optical illusion, said co-lead author Dakota "Cody" McCoy, a Yale graduate now with the Department of Organismic and Evolutionary Biology at Harvard.
"An apple looks red to us whether it is sitting in the bright sunlight or in the shade because all vertebrate eyes and brains have special wiring to adjust their perception of the world according to ambient light," McCoy said. "Birds of paradise, with their super-black plumage, increase the brilliance of adjacent colors to our eyes, just as we perceive the red even though the apple is in the shade."
[Image: 1-evolvedillus.jpg]   
A frontal view of a male bird of paradise’s mating display. Credit: Ed Scholes
Intriguingly, said the researchers, the microstructures in the feathers of the bird of paradise not involved in mating display lack the characteristics of the ultra-black plumage, another testimony to the importance of sexual selection in evolution.
"Sexual selection has produced some of the most remarkable traits in nature," Prum said. "Hopefully, engineers can use what the bird of paradise teaches us to improve our own human technologies as well."
[Image: 2-evolvedillus.jpg]
Top right, microstructure of super black feather from Paradise Riflebird still appears black even after being coated with gold, bottom right. Credit: Yale University
[Image: 1x1.gif] Explore further: Bird feathers inspire researchers to produce vibrant new colors
More information: Dakota E. McCoy et al. Structural absorption by barbule microstructures of super black bird of paradise feathers, Nature Communications (2017). DOI: 10.1038/s41467-017-02088-w

Journal reference: Nature Communications [Image: img-dot.gif] [Image: img-dot.gif]
Provided by: Yale University


Read more at: https://phys.org/news/2018-01-evolved-il...e.html#jCp

[/url]
Solving Darwin's 'abominable mystery': How flowering plants conquered the world
January 11, 2018, [url=http://www.plos.org/]Public Library of Science



[Image: floweringpla.jpg]
Credit: CC0 Public Domain
Scientists have found an explanation for how flowering plants became dominant so rapidly in ecosystems across the world—a problem that Charles Darwin called an 'abominable mystery'. In a study publishing on January 11 in the open access journal PLOS Biology, Kevin Simonin and Adam Roddy, from San Francisco State University and Yale University respectively, found that flowering plants have small cells relative to other major plant groups and that this small cell size is made possible by a greatly reduced genome size.


Read more at: https://phys.org/news/2018-01-darwin-abo...d.html#jCp




In 'pond scum,' scientists find answers to one evolution's which-came-first cases
January 10, 2018, Boston College


[Image: inpondscumsc.jpg]
Example of a living representative of a primitive moth belonging to the Glossata, moths that bear a proboscid adapted for sucking up fluids, including nectar. Size of the scale bar is 1 cm. Credit: Hossein Rajaei, Museum für Naturkunde
Visiting a colleague in Germany in 2012, Boston College Research Professor Paul K. Strother was examining soil samples for pollen, spores, pieces of plants and insect legs - organic debris that might otherwise have been considered "pond scum" when it was trapped in sediment during cataclysmic earth events 200 million years ago.


Read more at: https://phys.org/news/2018-01-pond-scum-...t.html#jCp



Pond scum explains evolution of first animals
January 8, 2018 by Emily Moskal, Astrobiology Magazine, Astrobio.net


[Image: pondscumexpl.jpg]
Dickinsonia costata, one of the most common species of the Ediacaran period, moved and fed on seafloor microbe mats. This specimen and its silly putty cast are about 6 centimeters across and from the Nilpena Station of South Australia. Credit: Mary Droser

Microbial mats that existed on sea floors prior to the Cambrian explosion provided the foundation for early animal life to arise, new research looking at trace fossils of that early life has found.

When Charles Darwin wrote On the Origin of Species and for decades thereafter, scientists ascribed the beginning of animal life to the Cambrian, eventually pinned to about 540 million years ago when trilobites and other multicellular organisms emerged in a relatively short timeframe.
In recent years, however, astonishing complexity has been discovered in the period right before the advent of the Cambrian explosion, revising the scientific view of the origins of the most complex, multicellular life on Earth.

Source:: Astrobio.net


Read more at: https://phys.org/news/2018-01-pond-scum-...s.html#jCp
Along the vines of the Vineyard.
With a forked tongue the snake singsss...
Reply
#15
Quote:"Thanks to collaborations among field workers and geneticists, we now understand that the raven is anything but common."

Other... [Image: ninja.gif]   Uncommon Senses. TM [Image: doh.gif]

Two species of ravens nevermore?
New research finds evidence of 'speciation reversal' youareaduck
March 2, 2018, University of Washington


[Image: twospeciesof.jpg]
A raven is shown in the rain. Credit: Bjørn Aksel Bjerke/University of Oslo

For over a century, speciation—where one species splits into two—has been a central focus of evolutionary research. But a new study almost 20 years in the making suggests "speciation reversal"—where two distinct lineages hybridize and eventually merge into one—can also be extremely important. The paper, appearing March 2 in Nature Communications, provides some of the strongest evidence yet of the phenomenon, in two lineages of  Common Ravens.

"The bottom line is [speciation reversal] is a natural evolutionary process, and it's probably happened in hundreds or almost certainly thousands of lineages all over the planet," said Kevin Omland, professor of biological sciences at University of Maryland, Baltimore County (UMBC) and co-author on the new study. "One of our biggest goals is to just have people aware of this process, so when they see interesting patterns in their data, they won't say, 'That must be a mistake,' or, 'That's too complicated to be correct.'"

"We examined genomic data from hundreds of ravens collected across North America," said Anna Kearns, the study's first author and a former postdoctoral fellow at UMBC, who is now a postdoc at the Smithsonian Center for Conservation Genomics. "Integrating all of the results across so many individuals, and from such diverse datasets, has been one of the most challenging aspects of this study. Next-generation genomic techniques are revealing more and more examples of species with hybrid genomes."

When Omland initially began work on this project in 1999, Common Ravens were considered a single species worldwide. He thought further research might uncover two distinct species—perhaps an "Old World" and "New World" raven—but the real story is much more complicated. Omland reported the existence of two Common Raven lineages in 2000, one concentrated in the southwestern United States dubbed "California," and another found everywhere else (including Maine, Alaska, Norway and Russia) called "Holarctic."
[Image: 1-twospeciesof.jpg]
A raven is shown perching in the snow. Credit: Bjørn Aksel Bjerke/University of Oslo

Since then, the plot has thickened. Two undergraduates in Omland's lab, Jin Kim and Hayley Richardson, analyzed mitochondrial DNA from throughout the western United States and found the two lineages are extensively intermixed. In 2012, the Norwegian Research Council provided major funding for the project and Kearns spent a year at the University of Oslo analyzing nuclear genome data.
The best explanation based on the team's analysis is that the California and Holarctic lineages diverged for between one and two million years, but now have come back together and have been hybridizing for at least tens of thousands of years.

"The extensive genetic data reveals one of the best supported examples of speciation reversal of deeply diverged lineages to date," said Arild Johnsen, professor of zoology and evolutionary biology at University of Oslo and another leader of the study. "The biggest thing is the degree to which we've caught them in the act."
How does this relate to people? Humans are also a product of speciation reversal, Omland notes, with the present-day human genome including significant chunks of genetic material from Neanderthals and Denisovans, another less well-known hominid lineage. Recent genetic studies have even indicated a mysterious fourth group of early humans who also left some DNA in our genomes.
[Image: 2-twospeciesof.jpg]
A pair of ravens interact on a branch. Credit: Bjørn Aksel Bjerke/University of Oslo

"Because speciation reversal is a big part of our own history," Omland said, "getting a better understanding of how that happens should give us a better sense of who we are and where we came from. These are existential questions, but they are also medically relevant as well."
Next steps in the current avian research include analyzing genetic data from ravens who lived in the early 1900s to investigate the potential role of humans in the speciation reversal process. "Getting genomic data out of such old, degraded specimens is challenging," Kearns said, "and all work must be done in a special 'ancient DNA' lab at the Smithsonian's Center for Conservation Genomics."
If those ravens have a similar distribution of genes from the Holarctic and California lineages as the ravens living today, it's unlikely changes in human civilization over the last century played a role.
Co-author John Marzluff, professor of wildlife science at the University of Washington, summed up the experience of being part of the study: "It is fascinating to me that this complex history of raven speciation has been revealed. For decades my students and I held and studied ravens throughout the West and never once suspected they carried evidence of a complex past," he said. "Thanks to collaborations among field workers and geneticists, we now understand that the raven is anything but common."


[Image: 1x1.gif] Explore further: Green toads with multiple genomes have ancestors that are only distantly related
More information: Anna M. Kearns et al. Genomic evidence of speciation reversal in ravens, Nature Communications (2018). DOI: 10.1038/s41467-018-03294-w

Journal reference: Nature Communications [/url]
Provided by: [url=https://phys.org/partners/university-of-washington/]University of Washington



Read more at: https://phys.org/news/2018-03-species-ra...n.html#jCp






Previously unknown 'supercolony' of Adélie penguins discovered in Antarctica

March 2, 2018, Woods Hole Oceanographic Institution


[Image: previouslyun.jpg]
The researchers found that the Danger Islands have 751,527 pairs of Adélie penguins--more than the rest of the entire Antarctic Peninsula region combined. They include the third and fourth largest Adélie penguin colonies in the world. Credit: Michael Polito, Louisiana State University

For the past 40 years, the total number of Adélie Penguins, one of the most common on the Antarctic Peninsula, has been steadily declining—or so biologists have thought. A new study led by researchers from the Woods Hole Oceanographic Institution (WHOI), however, is providing new insights on of this species of penguin. In a paper released on March 2nd in the journal Scientific Reports, the scientists announced the discovery of a previously unknown "supercolony" of more than 1,500,000 Adélie Penguins in the Danger Islands, a chain of remote, rocky islands off of the Antarctic Peninsula's northern tip.



"Until recently, the Danger Islands weren't known to be an important penguin habitat," says co-PI Heather Lynch, Associate Professor of Ecology & Evolution at Stony Brook University. These supercolonies have gone undetected for decades, she notes, partly because of the remoteness of the islands themselves, and partly the treacherous waters that surround them. Even in the austral summer, the nearby ocean is filled with thick sea ice, making it extremely difficult to access.

Yet in 2014, Lynch and colleague Mathew Schwaller from NASA discovered telltale guano stains in existing NASA satellite imagery of the islands, hinting at a mysteriously large number of penguins. To find out for sure, Lynch teamed with Stephanie Jenouvrier, a seabird ecologist at WHOI, Mike Polito at LSU and Tom Hart at Oxford University to arrange an expedition to the islands with the goal of counting the birds firsthand.

When the group arrived in December 2015, they found hundreds of thousands of birds nesting in the rocky soil, and immediately started to tally up their numbers by hand. The team also used a modified commercial quadcopter drone to take images of the entire island from above.

[Image: 1-previouslyun.jpg]
Using estimations from ground counts and computer-automated counts from an unmanned aerial vehicle, the research team was able to complete the first census of Adélie penguins in the Danger Islands. Credit: Rachael Herman, Louisiana State University, Stony Brook University

"The drone lets you fly in a grid over the island, taking pictures once per second. You can then stitch them together into a huge collage that shows the entire landmass in 2D and 3D," says co-PI Hanumant Singh, Professor of Mechanical and Industrial Engineering at Northeastern University, who developed the drone's imaging and navigation system. Once those massive images are available, he says, his team can use neural network software to analyze them, pixel by pixel, searching for penguin nests autonomously.

The accuracy that the drone enabled was key, says Michael Polito, coauthor from Louisiana State University and a guest investigator at WHOI. The number of penguins in the Danger Islands could provide insight not just on penguin population dynamics, but also on the effects of changing temperature and sea ice on the region's ecology.

"Not only do the Danger Islands hold the largest population of Adélie penguins on the Antarctic Peninsula, they also appear to have not suffered the population declines found along the western side of Antarctic Peninsula that are associated with recent climate change," says Polito.

Read more at: https://phys.org/news/2018-03-previously...s.html#jCp
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#16
glutamate Arrow

Brain genes related to innovation revealed in birds
March 14, 2018, McGill University


[Image: braingenesre.jpg]
Barbados bullfinch innovation in the wild: opening sugar packets. Credit: Louis Lefebvre

Wild birds that are more clever than others at foraging for food have different levels of a neurotransmitter receptor that has been linked with intelligence in humans, according to a study led by McGill University researchers. The findings could provide insight into the evolutionary mechanisms affecting cognitive traits in a range of animals.



The study, published in Science Advances, was conducted by McGill biologists Jean-Nicolas Audet and Louis Lefebvre, in collaboration with researchers from Duke and Harvard universities.

Barbados birds

The researchers caught bullfinches and black-faced grassquits near McGill's Bellairs Research Institute in Barbados. Bullfinches are bold, opportunistic and innovative, while grassquits are shy and conservative. They are each other's closest relative in Barbados and are cousins of Darwin's finches from the Galápagos islands.

In captivity, the problem-solving skills of the two species differed considerably in lab tests. Most of the bullfinches quickly figured out how to lift the lid off a jar of food, for example, while all the grassquits were stumped by the challenge. These performances were in line with the differences in the birds' innovativeness in the wild—a trait that can help animals survive in changing environments.

New tools for the study of wild behavior

The researchers then compared the expression of all genes in six parts of the brain of the two bird species using state-of-the-art molecular techniques, including next-generation sequencing - the first time these tools have been used to find brain properties related to innovation and problem-solving in wild birds.

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Bullfinch solving an experimental problem in Barbados. Credit: Louis Lefebvre

A family of genes stood out: glutamate neurotransmitter receptors, especially in the part of the bird brain that corresponds to humans' prefrontal cortex.

Glutamate receptors are known to be involved in a variety of cognitive traits in humans and other mammals. In particular a receptor known as GRIN2B, when boosted in transgenic mice, makes them better learners. Levels of that receptor were higher in the Barbados bullfinch than in the grassquit, the researchers found.

"By comparing an extremely innovative species like the Barbados bullfinch with a closely related conservative one like the black-faced grassquit, we gain insight into the evolutionary mechanisms that can lead to divergence in behavior," Audet says. "It might be that mammals, including humans, and birds like the Barbados bullfinch use similar mechanisms to perform cognitively. If our results are confirmed in future studies, it would be a unique demonstration of convergent evolution of intelligence, involving the same neurotransmitter receptors despite the widely different brain structures of birds and mammals."



[Image: 1x1.gif] Explore further: Two Barbados bird species enter the select club of string-pullers

More information: "Divergence in problem-solving skills is associated with differential expression of glutamate receptors in wild finches," Jean-Nicolas Audet, et al. Science Advances, March 14, 2018. DOI: 10.1126/sciadv.aao6369


Journal reference: Science Advances [Image: img-dot.gif] [Image: img-dot.gif]
Provided by: McGill University


Read more at: https://phys.org/news/2018-03-brain-gene...s.html#jCp



ADHD drugs increase brain glutamate, predict positive emotion in healthy people
March 14, 2018, Brown University

[Image: adhddrugsinc.jpg]
A new study used MRI to show how ADHD drugs affect the brains of healthy people. The study found that the drugs were associated with a surge in the neurotransmitter glutamate in key regions of the brain. That surge was associated with …more
A new study shows that healthy people who take attention deficit hyperactivity disorder (ADHD) drugs experience a surge in the neurotransmitter glutamate in key parts of the brain. And that increase in glutamate is associated with subsequent changes in positive emotion.

The findings, published in the journal Neuropsychopharmacology, not only provide clues about how these drugs affect healthy brains, they also hint at a previously undiscovered link between glutamate and mood.
"This is the first time that an increase in brain glutamate in response to psychostimulant drugs has been demonstrated in humans," said Tara White, an assistant professor in the Brown University School of Public Health and lead author of the new study. "That's important since glutamate is the major neurotransmitter responsible for excitation in the brain, and affects learning and memory."
Even more interesting, White said, the rise in glutamate predicted the magnitude and the duration of positive emotional responses to the drug.
"Given the timing of these effects—the glutamate effect comes first, and the positive emotion comes later—this could indicate a causal link between glutamate and positive emotion," White said. I think what we're seeing here is not just a drug effect, it's how positive emotion works in humans."
Drug effects on the brain
Millions of kids nationwide take prescription medication to treat ADHD. But in addition to prescribed usage, there's a thriving black market for these drugs, which young people use to improve attention, mood, and work and school performance. Yet little is known about what effects these drugs have on healthy brains, White said.
In this new study, subjects were first screened for mental and physical health and then underwent MRI spectroscopy scans designed to detect the concentration of neural compounds in specific regions of their brain. From the medical literature on psychostimulants, White and her team wanted to look in the anterior cingulate cortex, which is a "hub" brain region that connects multiple brain networks involved in emotion, decision-making and behavior.

They found that two ADHD medications, d-amphetamine and Desoxyn, significantly increased the overall amount of glutamate in the right dorsal anterior cingulate cortex, even after controlling for possible confounding factors, such as volume of gray matter in the region. The rise in brain glutamate predicted both the duration and the intensity of positive emotion, measured by participant ratings about whether they liked the drug or felt high after consuming it.
The authors caution that while this was a placebo-controlled study, the research demonstrates only an association between glutamate and positive mood, and not necessarily a causal relationship. However, the fact that the mood changes consistently followed changes in glutamate is suggestive of causality, though more research is necessary.
Glutamate is the most abundant neurotransmitter in the brain, White said, and its roles in learning and memory are well established. A potential link between glutamate and mood would be a novel finding.
"This is the first time we've seen a link between increases in brain glutamate and increases in positive emotion in healthy people—with both changes happening in real time," said White, who is based at Brown's Center for Alcohol and Addiction Studies. "I think it's going to open up a whole new way of thinking about emotion in humans."
The research also found evidence of gender differences in drug effects. Women in the sample showed a larger increase in glutamate compared to the men in the sample. Women also responded more strongly to Desoxyn, compared to d-amphetamine. The gender difference is consistent with prior studies in animals, which show greater stimulant drug effects in females compared to males. The differences between the two drugs also indicate that ADHD medications can have different effects on glutamate and other compounds in the brain.
White and her colleagues say there's evidence to suggest that the increase in glutamate involved drug-induced changes in enzymes and glutamate precursors. That suggests that the glutamate signal the researchers saw was from newly produced glutamate, rather than reuptake. With further research, the new data could help scientists to better understand how individuals respond differently to drugs, and changes in positive emotion over time.
"[The] present findings provide the first evidence in humans that drug-induced changes in [glutamate] correlate with subjective experiences of drug liking and drug high following drug ingestion" White and colleagues wrote.
[Image: 1x1.gif] Explore further: Study finds neurotransmitter may play a role in alcohol relapse, addiction
More information: Tara L. White et al, Psychostimulant drug effects on glutamate, Glx, and creatine in the anterior cingulate cortex and subjective response in healthy humans, Neuropsychopharmacology (2018). DOI: 10.1038/s41386-018-0027-7

Journal reference: Neuropsychopharmacology [Image: img-dot.gif] [Image: img-dot.gif]
Provided by: Brown University
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#17
larynx Sheep syrinx.

I taught eye taw a wascally wabbit.



Birds' voiceboxes are odd ducks
September 24, 2018, Field Museum


[Image: birdsvoicebo.jpg]
A singing bird (Dickcissel, Spiza americana). Birds are able to sing thanks to a unique organ called the syrinx. Credit: John Bates, Field Museum
Birds sing from the heart. While other four-limbed animals like mammals and reptiles make sounds with voiceboxes in their throats, birds' chirps originate in a unique vocal organ called the syrinx, located in their chests. No other animals have a syrinx, and scientists aren't sure how or when it evolved. In a new study in the Proceedings of the National Academy of Science, an interdisciplinary team of developmental biologists, evolutionary morphologists, and physiologists examined the windpipes of birds, crocodiles, salamanders, mice, and cats to learn more about how syrinxes evolved. Their findings seem to confirm: the syrinx is an evolutionary odd duck. But it might have arisen from a reinforcement at the bottom of the windpipe that we still see in many other animals.



"Birds have a unique organ in their airway to produce sounds—it's like a flute," says Chad Eliason, a postdoctoral researcher at Chicago's Field Museum and co-first author of the study. "We don't know where that organ came from, how and why it evolved. But in this study, when we zoomed out and looked at the windpipes of other animals, we found deep similarities that we didn't expect."

Mammals, birds, and reptiles all have a trachea—a tube connecting the nose and mouth to the lungs. And we all have a larynx—a hollow, muscular organ at the top of that tube that helps air pass through to the lungs and keeps food from falling into the airway. In mammals and reptiles, the larynx has little folds of tissue that vibrate when air passes over them, producing sound. In birds, the larynx can't produce sound—it's only there for breathing and eating. Instead, birds' sounds are produced at the bottom of the trachea, just above where the trachea branches into the lungs. This juncture, made of cartilage, is the syrinx.

"The syrinx is a tiny box of cartilage—in a sparrow, it's about 8 millimeters in diameter, about four times the thickness of a strand of spaghetti," says Eliason. "It reinforces the airway, and when air passes over the folds in it, it produces a sound: birdsong."

[Image: 1-birdsvoicebo.jpg]
Three-dimensional models of interior tracheal cartilage structure in alligators (left) and ducks (right). Syringeal muscles shown in red and yellow. Vocal folds in pink. Specimens were scanned at The University of Texas High-Resolution CT Facility. Credit: Evan Kingsley, Chad Eliason, et al
Since birds have both a syrinx and a larynx, it's unclear exactly when the syrinx took over sound production duty for the larynx. "Birds' closest living relatives, crocodiles, produce sound in their throats with a larynx. So how did ancestors of birds transition from making sounds with their larynx to making sounds with their syrinx?" asks Eliason. "If we found fossil evidence of a syrinx in dinosaurs, that would be a smoking gun, but we haven't yet. In the meantime, we have to look at other animals for clues."

Eliason and his fellow scientists, including co-first author Evan Kingsley of Harvard Medical School, examined the tracheas of a suite of animals. Cats, mice, and crocs all have a set of fused cartilage rings at the base of the trachea, called the carina, that provides structural support where the trachea branches to the lungs—just like a syrinx does. "Perhaps the syrinx is just a byproduct of reinforcing the airway, like a carina does in other animals," says Eliason.

 

The existence of structures like the syrinx and the carina aren't new to science—people have known about them for decades. But this study provides a new way of looking at them. "We're deepening our understanding of how these structures are related to each other, and that could help us understand how the syrinx evolved in the first place," says Julia Clarke, professor at University of Texas at Austin and a leading author of the study.

[Image: birdsreinven.jpg]
Two primary hypotheses for the evolutionary transition from a laryngeal sound source to a syringeal sound source (blue shaded box). Auditory innovations are shown as black dashes and suggest a sustained role for acoustic communication in archosaurs. Understanding whether the shift to a syringeal sound source occurred early or late in bird-lineage archosaurs will require further comparative genomic and paleontological work. Credit: Julia Clarke et al.

Read more at: https://phys.org/news/2018-09-birds-voic...s.html#jCp

Chinese Cretaceous fossil highlights avian evolution
September 24, 2018, Chinese Academy of Sciences


[Image: chinesecreta.jpg]
A 127-million-year-old fossil bird, Jinguofortis perplexus (reconstruction on the right, artwork by Chung-Tat Cheung), second earliest member of the short-tailed birds Pygostylia. Credit: WANG Min
A newly identified extinct bird species from a 127 million-year-old fossil deposit in northeastern China provides new information about avian development during the early evolution of flight.



Drs. Wang Min, Thomas Stidham, and Zhou Zhonghe from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences reported their study of the well-preserved complete skeleton and feathers of this early bird in the Proceedings of the National Academy of Sciences (PNAS).

The analysis of this early Cretaceous fossil shows it is from a pivotal point in the evolution of flight—after birds lost their long bony tail, but before they evolved a fan of flight feathers on their shortened tail.

The scientists named this extinct species Jinguofortis perplexus. The genus name "Jinguofortis" honors women scientists around the world. It derives from the Chinese word "jinguo," meaning female warrior, and the Latin word "fortis" meaning brave.

Jinguofortis perplexus has a unique combination of traits, including a jaw with small teeth like its theropod dinosaur relatives; a short bony tail ending in a compound bone called a pygostyle; gizzard stones showing that it mostly ate plants; and a third finger with only two bones, unlike other early birds.

[Image: 1-chinesecreta.jpg]
Major changes of the coracoid and scapula (main components of the shoulder girdle) across the major vertebrate groups; the right is a simplified cladogram shows the phylogeny of Mesozoic birds with highlights of the changes of the shoulder and hand. Credit: WANG Min
The fossil's shoulder joint also gives clues about its flight capacity. In flying birds, the shoulder, which experiences high stress during flight, is a tight joint between unfused bones. In contrast, Jinguofortis perplexus preserves a shoulder girdle where the major bones of the shoulder, the shoulder blade (scapula) and the coracoid, are fused to one another, forming a scapulocoracoid.

The existence of a fused shoulder girdle in this short-tailed fossil suggests evolutionary variety during this stage of evolution, which probably resulted in different styles of flight.Based on its skeleton and feathers, Jinguofortis perplexus probably flew a bit differently than birds do today.

Measurement of the fossil's wing size and estimation of its body mass show that the extinct species had a wing shape and wing loading (wing area divided by body mass) similar to living

[Image: 1x1.gif] Explore further: Fossil find pushes back date of earliest fused bones in birds by 40 million years

More information: Min Wang el al., "A new clade of basal Early Cretaceous pygostylian birds and developmental plasticity of the avian shoulder girdle," PNAS (2018). www.pnas.org/cgi/doi/10.1073/pnas.1812176115


Journal reference: Proceedings of the National Academy of Sciences [Image: img-dot.gif] [Image: img-dot.gif]
Provided by: Chinese Academy of Sciences


Read more at: https://phys.org/news/2018-09-chinese-cr...n.html#jCp
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#18
RE: A little bird told me... a funny story of evolution.

[Image: hqdefault.jpg]

reaching weights of up to 800 kg and three metres tall, Holycowsmile


Team names world's largest ever bird—Vorombe titan 
September 25, 2018, Zoological Society of London


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An artist's illustration of the giant elephant bird. Credit: © Jaime Chirinos
After decades of conflicting evidence and numerous publications, scientists at international conservation charity ZSL's (Zoological Society of London) Institute of Zoology, have finally put the 'world's largest bird' debate to rest. Published today (26 September 2018) in Royal Society Open ScienceVorombe titan (meaning 'big bird' in Malagasy and Greek), has taken the title reaching weights of up to 800 kg and three metres tall, with the research also discovering unexpected diversity in these Madagascan creatures.



Until now, it was previously suggested that up to 15 different species of elephant birds had been identified under two genera, however research by ZSL scientists boasts new rigorous and quantitative evidence—that shows, in fact, this is not the case. Armed with a tape measure and a pair of callipers, Dr. Hansford analysed hundreds of elephant bird bones from museums across the globe to uncover the world's largest bird, while also revealing their taxonomy is in fact spread across three genera and at least four distinct species; thus, constituting the first taxonomic reassessment of the family in over 80 years.

Elephant birds (belonging to the family Aepyornithidae) are an extinct group of colossal flightless birds that roamed Madagascar during the Late Quaternary, with two genera (Aepyornis and Mullerornis) previously recognised by scientists. The first species to be described, Aepyornis maximus, has often been considered to be the world's largest bird. In 1894, British scientist C.W. Andrews described an even larger species, Aepyornis titan, this has usually been dismissed as an unusually large specimen of A. maximus. However, ZSL's research reveals Andrew's 'titan' bird was indeed a distinct species. The shape and size of its bones are so different from all other elephant birds that it has now been given the new genus name Vorombe by ZSL.

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An artist's illustration of the giant elephant bird. Credit: © Heidi Ma
Lead Author at ZSL's Institute of Zoology, Dr. James Hansford said: "Elephant birds were the biggest of Madagascar's megafauna and arguably one of the most important in the islands evolutionary history—even more so than lemurs. This is because large-bodied animals have an enormous impact on the wider ecosystem they live in via controlling vegetation through eating plants, spreading biomass and dispersing seeds through defecation. Madagascar is still suffering the effects of the extinction of these birds today."

Co-Author Professor Samuel Turvey from ZSL's Institute of Zoology said: "Without an accurate understanding of past species diversity, we can't properly understand evolution or ecology in unique island systems such as Madagascar or reconstruct exactly what's been lost since human arrival on these islands. Knowing the history of biodiversity loss is essential to determine how to conserve today's threatened species."

[Image: 2-zslnamesworl.jpg]
Vorombe titan bones. Credit: © ZSL
Analysing this data in a novel combination of machine learning combined with Bayesian clustering, Dr. Hansford applied modern techniques to solve a 150-year-old taxonomic knot, that will form the modern understanding of these enigmatic avian megafauna. The revelation that the biggest of these birds was forgotten by history is just one part of their remarkable story.  

More information: Unexpected diversity within the extinct elephant birds (Aves: Aepyornithidae), and a new identity for the world's largest bird, Royal Society Open Science, rsos.royalsocietypublishing.or … /10.1098/rsos.181295

Journal reference: Royal Society Open Science [/url]
Provided by: [url=https://phys.org/partners/zoological-society-of-london/]Zoological Society of London



Read more at: https://phys.org/news/2018-09-team-world...n.html#jCp




[Image: ancientbirdb.jpg]
Ancient bird bones redate human activity in Madagascar by 6,000 years
[Image: 1x1.gif] September 12, 2018
Analysis of bones, from what was once the world's largest bird, has revealed that humans arrived on the tropical island of Madagascar more than 6,000 years earlier than previously thought—according to a study published ...


Read more at: https://phys.org/news/2018-09-team-world...n.html#jCp
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#19
from the improvisphere... Arrow

Quote:A University of Queensland researcher has uncovered how a French scientist and ibis researcher conducted the first test of evolution more than 50 years before Charles Darwin's Origin of the Species.

'Bin chicken' plays unique role in story of evolution
September 28, 2018, University of Queensland


[Image: binchickenpl.jpg]
(A) Empty and full pottery vessels from catacombs from Saqqara, Egypt (photo credit Sally Wasef), (B) mummified Sacred Ibis wrapped in cloth (photo credit Metropolitan Museum of Art, New York), © a well-preserved example of an unwrapped …more
A University of Queensland researcher has uncovered how a French scientist and ibis researcher conducted the first test of evolution more than 50 years before Charles Darwin's Origin of the Species.



UQ Centre for Policy Futures researcher Dr. Caitlin Curtis has found that the sacred ibis – a cousin of the Australian 'bin chicken' – became central to the history of evolution when several mummified birds were taken from Egypt to France in 1798.

"The ibis mummies were taken by Napoleon's army to Paris, and played a surprising role in an early debate about evolution," Dr. Curtis said.

"Two naturalists, Georges Cuvier and Jean-Baptist Lamarck, disagreed about the significance of the mummified Egyptian sacred ibises.

"Cuvier took careful measurements and determined that no changes had happened when comparing the mummified birds against modern specimens.

"He went on to conclude that this was proof that species could not change over time, opposing the emerging evolutionary ideas of Lamarck."

But Lamarck disagreed, arguing not enough time had passed to see any differences, and that environmental conditions would also have had to change.

"This was significant at a time when evolution was not yet an idea," Dr. Curtis said.
youareaduck
"Cuvier was a prominent scientist who had a lot of voice and power within society, and he continued the debate through to Lamarck's death—even criticising Lamarck's belief in evolution at his eulogy – setting back the idea for decades."
Quote:Posted by EA - Wednesday, May 22nd, 2013, 10:36 pm [Image: darwin.jpg]

Darwin would love this true story.
Dr. Curtis said it was a striking example of a powerful – but incorrect—scientist controlling the debate.

"This story and the lessons from the sacred ibis are as relevant today as they were 200 years ago," she said.

"Confirmation bias, where researchers' work is negatively affected by pre-existing biases and ideas, is still an issue within the scientific community.

"This is a reminder that now, as much as ever, we need to be aware of confirmation bias, and the detrimental impact that dominant personalities can have on science."

[Image: 1x1.gif] Explore further: Behavior of parent organisms may influence genes passed on to next generation

More information: Caitlin Curtis et al. The Sacred Ibis debate: The first test of evolution, PLOS Biology (2018). DOI: 10.1371/journal.pbio.2005558


Journal reference: PLoS Biology [Image: img-dot.gif] [Image: img-dot.gif]
Provided by: University of Queensland


Read more at: https://phys.org/news/2018-09-bin-chicke...y.html#jCp
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Quote:This finding demonstrates that the high durability of bird feathers against tears derives from their cascaded slide-lock system, not from the "hook-groove system" proposed centuries ago. Results were published in PNAS in an article titled "Repairable cascaded slide-lock system endows bird feathers with tear-resistance and superdurability."

Researchers discover how bird feathers resist tearing
October 1, 2018, Chinese Academy of Sciences


[Image: 2-chineseresea.jpg]
(A) The vane consists of a number of side branches, which are aligned in parallel and are called barbs. (B) The adjacent barbs overlap closely, forming the dense vane. The second-order side branches, called barbules, occur on both sides of barbs. (C and D) The hooklets from one barb hook the adjacent barbs and fasten the vane. (E ) Stereoscopic structure of a feather obtained via 3D reconstruction with a micro X-ray microscope. The hooklets hook the curved margin of the barbules on the adjacent barbs. Finer toothlike spine structures can be observed. (Scale bars: A, 3 cm, and Inset, 5 mm; B, 500 μm; C, 200 μm; D, 50 μm.) Credit: TIPC
Chinese researchers have discovered and characterized a sophisticated mechanism in bird feathers that enhances tear resistance, overturning a centuries-old explanation of how bird feathers work. The newly discovered cascaded slide-lock system is composed of flexible hooklets, a slide rail, and spines at the end of the slide rail as terminating structures.



This finding demonstrates that the high durability of bird feathers against tears derives from their cascaded slide-lock system, not from the "hook-groove system" proposed centuries ago. Results were published in PNAS in an article titled "Repairable cascaded slide-lock system endows bird feathers with tear-resistance and superdurability."

Bird feathers have aroused tremendous attention for their superdurability against tears during long flights through wind and even bushes. Although feathers may inevitably be unzipped, the separated feather vanes can be repaired easily by bill stroking, which shows the strong advantage of feathered wings over the membrane wings of bats and butterflies. However, the mechanism underlying bird feather superdurability against tears had previously been unclear.

Since Hooke drafted the first rough model of feather structures in 1665, many efforts have been made to explore the structure and function of feathers. Microscale hooks and grooves have been observed and illustrated using optical and electron microscopy. Unfortunately, to date, the superdurability of feathers against tears has remained linked to the interlocking hook-and-groove model, which ignored the fine structures in feathers and could not adequately explain their superdurability.

[Image: 3-chineseresea.jpg]
(A and B) The structure of a single barb from the dorsal view (A) and ventral view (B). Side branches on both sides of the barbs exhibit different structures called hook barbules and bow barbules. (C and D) A hook barbule contains approximately four pendulous, backward-facing hooklets in the middle. (E and F) The bow barbule, with a sharply curved margin, contains approximately four toothlike spine structures, called dorsal spines, with a scalene triangle shape at the distal end. (G and H) The hooklets and the curved triangle dorsal spines match in size and shape. (Scale bars: A and B, 500 μm; C and E, 50 μm; D and F, 20 μm; G and H, 5 μm.) Credit: TIPC
Researchers from the Technical Institute of Physics and Chemistry (TIPC) of the Chinese Academy of Sciences recently made a deep observation of the 3-D fine structures and the entire unzipping process of feathers by using microscopy with a micro/nano manipulating system and 3-D X-ray microscopy.

They observed a repairable cascaded slide-lock system comprising hooklets, and a slide rail with spines at the end as terminating structures. They also clearly discerned the function of each part. The hooklets can slide along the slide rail in reverse when affected by external forces. The sliding hooklet can be locked by the spine at the ends of barbules when larger pulling forces are applied and slide even farther away due to the unzipping of the interlocking structure with large deformation of the barbules.

This system not only enhances the separation force of adjacent barbs, but also prevents damage to the barbs during separation. The separation force of adjacent barbs can be maintained above 80 percent of the initial value even after 1,000 cycles of separation and repair. That is, this cascaded slide-lock system of feathers ensures their superdurability and high self-repair capability, thus helping birds survive in hostile environments. These findings also provide insight into the design of smart textiles and flexible devices.

[Image: 1x1.gif] Explore further: What makes penguin feathers ice-proof

More information: Feilong Zhang et al, Repairable cascaded slide-lock system endows bird feathers with tear-resistance and superdurability, Proceedings of the National Academy of Sciences (2018). DOI: 10.1073/pnas.1808293115


Journal reference: Proceedings of the National Academy of Sciences [Image: img-dot.gif] [Image: img-dot.gif]
Provided by: Chinese Academy of Sciences


Read more at: https://phys.org/news/2018-10-bird-feath...t.html#jCp
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#21
Teaching wild birds to sing a new tune
October 4, 2018, Cell Press


[Image: teachingwild.jpg]
Ows researcher Dan Mennill with the loudspeaker he designed to tutor sparrows in song. Credit: Dan Mennill
Like toddlers learning to speak, young birds learn to sing by listening to the voices of adults. Now, researchers reporting in Current Biology on October 4 have shown for the first time that they could teach young sparrows in the wild how to sing a new tune. The wild birds then passed the new songs on to the next generation.



"I was quite shocked that our loudspeakers succeeded in teaching wild birds to sing," says Dan Mennill (@DMennill) from the University of Windsor in Ontario, Canada. "The sparrows in our island-living population had abundant opportunities to learn songs from live tutors, and yet thirty birds learned songs from the loudspeakers, providing experimental evidence of vocal learning."

Conventional experiments of vocal learning in birds have been conducted in the laboratory. But such studies are much more difficult to do in the wild. The researchers overcame the challenges in the new study by focusing their attention on Savannah Sparrows living at Bowdoin Scientific Station on Kent Island. The sparrows on this island often return to the place of their birth to breed as adults. That made it possible for researchers to expose young birds to novel songs and then record those same animals when they returned from migration to breed the next year.

Mennill's team, including researchers from the University of Windsor, University of Guelph, and Williams College, developed a new type of loudspeaker that is programmable, solar powered, light activated, and weatherproof. The speakers allowed them to broadcast adult songs with distinctive acoustic signatures for the wild sparrows over tutoring sessions that lasted for months. Over a six-year period between 2013 and 2018, they experimentally tutored five cohorts of Savannah Sparrows, from the time they hatched to adulthood.

[Image: 1-teachingwild.jpg]
A Savannah sparrow. Credit: Dan Mennill
Across the five cohorts, thirty birds produced songs that matched the broadcasted songs. Those songs differed from anything the birds would have heard otherwise. In all thirty cases, the researchers report, the birds produced songs containing phrases that had never been recorded on the island in three decades of field study.

The findings confirm that wild Savannah Sparrows learn songs by listening to adult Savannah Sparrows. When those young sparrows become adults, they then pass these new songs on to subsequent generations. The new findings also provide the first experimental evidence that the timing of exposure to song influences vocal learning in wild birds. The Savannah Sparrows preferentially learned songs heard in the summer they hatched and then again at the outset of their first breeding season the following year.

Mennill says this study population of Savannah Sparrows, in which some males have learned typical songs and others have learned unusual songs, now presents unique opportunities for further study.

"In the years ahead, our research team will return to Kent Island and track the fate of these unusual songs and the activities of the males that sing them," he says.

[Image: 2-teachingwild.jpg]
A Savannah sparrow. Credit: Dan Mennill
[Image: 1x1.gif] Explore further: Cultural evolution changes bird song

More information: Current Biology, Mennill et al.: "Wild Birds Learn Songs from Experimental Vocal Tutors" https://www.cell.com/current-biology/ful...18)31056-X , DOI: 10.1016/j.cub.2018.08.011


Journal reference: Current Biology [Image: img-dot.gif] [Image: img-dot.gif]
Provided by: Cell Press


Read more at: https://phys.org/news/2018-10-wild-birds-tune.html#jCp


Birds in Minnesota keep crashing into things and police think it's because they're drunk
By Christina Maxouris and Brandon Griggs, CNN
Updated 4:53 PM ET, Thu October 4, 2018



[Image: 181004102106-birds-with-berries-restrict...ge-169.jpg]A bird on a berry bender.

(CNN)Robins, cedar waxwings and other birds in Gilbert, Minnesota, are flying into windshields, bumping into trees and looking mighty disoriented.
Police there say there's no need to worry -- the birds are just a little drunk.
"It appears some birds are getting a little more 'tipsy' than normal," Gilbert Police Chief Ty Techar wrote this week in a Facebook post.
No, the town's birds aren't downing worm-flavored margaritas. Techar believes their confused state is the result of eating berries that have fermented earlier than usual due to an early frost.
"Many birds have not migrated south, so it appears to be more prevalent than in past years," he said. "Younger birds' livers cannot handle the toxins as efficiently as more mature birds."
Is this true? Are the birds really drunk?
Yes, said Anna Pidgeon, an associate professor at the University of Wisconsin's Department of Forest and Wildlife Ecology, who notes it's not a rare phenomenon.
"It's more typical in late winter, early spring when berries that have been on branches ferment due to the yeast that's on them," she said.
Robins and cedar waxwings rely primarily on fruit and are more susceptible to "getting drunk," said Pidgeon. (Yes, that's really her name.)
Getting intoxicated can be quite dangerous for them, she said.
[Image: 181004131506-2-yellow-rumped-warbler-med...s-169.jpeg]A yellow-rumped warbler.
"(They) lose their coordination, they lose their natural ability to escape predators -- including poor judgment when it comes to flying."
The birds can also get alcohol poisoning.
Pidgeon recommends that anyone who finds a woozy bird should put it a dark, safe place -- such as a shed or a cardboard box -- until it recuperates and can fly without crashing into things. Drawing blinds can also help protect confused birds that may try to fly into windows, she said.
During mass migrations, young, naïve birds often collide with windows, getting concussions or breaking their necks. That, Pidgeon said, is the bigger problem.
"Relative to other sources of fatality of birds, alcohol poisoning isn't a huge risk," she said. "It's very short term."
Expert: No, it has more to do with migration
But Laura Erickson, author of the "National Geographic Pocket Guide to Birds of North America," said most of what people are seeing in northern Minnesota are not drunk birds at all.
She said she's gotten hundreds of calls and emails from people who say they've seen birds running into cars and homes. But none of those birds, Erickson said, has been the fruit-eating kind.
Instead, she said, they're yellow-rumped warblers and sparrows migrating through Minnesota. So far this fall the state is seeing an especially heavy flow of birds passing through, flying closer to the ground in search of food, she said.
"There may be some intoxicated birds up in Gilbert, but this (migration) is so widespread right now," said Erickson, who lives in Minnesota. "This is precisely the time of year when we get our peak migration of sparrows and yellow-rumped warblers."
But what about the poor drunk birds in Gilbert?
Techar, the police chief, said not to be alarmed. The birds will just sleep it off.
"There is no need to call law enforcement about these birds," he said, "as they should sober up within a short period of time."
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#22
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#23
New Caledonian crows can create tools from multiple parts
October 24, 2018, University of Oxford

[Image: 2-newcaledonia.jpg]
New Caledonian crow. Credit: Auguste von Bayern
An international team of scientists from the Max Planck Institute for Ornithology and the University of Oxford has revealed that New Caledonian crows are able to create tools by combining two or more otherwise non-functional elements, an ability so far observed only in humans and great apes.




The new study, published today in Scientific Reports, shows that these birds can create long-reaching tools out of short combinable parts - an astonishing mental feat. Assemblage of different components into novel functional and manoeuvrable tools has, until now, only been observed in apes, and anthropologists regard early human compound tool manufacture as a significant step in brain evolution. Children take several years before creating novel tools, probably because it requires anticipating properties of as yet unseen objects. Such anticipation, or planning, is usually interpreted as involving creative mental modelling and executive functions.

The study demonstrates that this species of crow possesses highly flexible abilities that allow them to solve complex problems involving anticipation of the properties of objects they have never seen.

'The finding is remarkable because the crows received no assistance or training in making these combinations, they figured it out by themselves,' said Auguste von Bayern, from the Max Planck Institute for Ornithology and the University of Oxford. The New Caledonian crows (Corvus moneduloides) from the South Pacific are of the same species as Betty, who became famous in 2002 as the first animal shown to be able to create a hooked tool by bending a pliable material.


Watch Tumulte, Jungle and Mango create and use compound tools. Credit: University of Oxford
Researchers had already been able to show how this remarkable species was able to use and make tools in the wild and in captivity, but they had never previously been seen to combine more than one piece to make a tool.

Alex Kacelnik, from the University of Oxford's Department of Zoology, said: 'The results corroborate that these crows possess highly flexible abilities that allow them to solve novel problems rapidly, but do not show how they do it. It is possible that they use some form of virtual simulation of the problem, as if different potential actions were played in their brains until they figure out a viable solution, and then do it. Similar processes are being modelled on artificial intelligences and implemented in physical robots, as a way to better understand the animals and to discover ways to build machines able to reach autonomous creative solutions to novel problems.'



The researchers presented eight New Caledonian crows with a puzzle box they had never encountered before, containing a small food container behind a door that left a narrow gap along the bottom. Initially, the scientists left some sufficiently long sticks scattered around, and all the birds rapidly picked one of them, inserted it through the front gap, and pushed the food to an opening on the side of the box. All eight birds did this without any difficulty. In the next steps, the scientists left the food deep inside the box but provided only short pieces, too short to reach the food. These short pieces could potentially be combined with each other, as some were hollow and others could fit inside them. In one example, they gave the birds barrels and plungers of disassembled hypodermic syringes. Without any help or demonstration, four of the crows partially inserted one piece into another and used the resulting longer compound pole to reach and extract the food. At the end of the five-step investigation, the scientists made the task more difficult by supplying even shorter combinable parts, and found that one particular bird, 'Mango', was able to make compound tools out of three and even four parts.

Although the authors explain that the mental processes by which the birds achieve their goals have not yet been fully established, the ability to invent a tool is interesting in itself. Few animals are capable of making and using tools, and also in human development the capacity only emerges late. While children start using tools reliably when they are about 18 months old, they only invent novel tools suited to solve a given problem reliably when they are at least five years old. Archaeological findings indicate that such compound tools arose only late in human cultural evolution (probably around 300,000 years ago in the Middle Palaeolithic) and might have coevolved with planning abilities, complex cognition and language. The crows' ability to construct novel compound tools does not imply that their cognitive mechanisms equal those of humans or apes, but helps to understand the cognitive processes that are necessary for physical problem solving.



[Image: 3-newcaledonia.jpg]
Credit: University of Oxford
[Image: 1x1.gif] Explore further: Crows 'reverse engineer' tools from memory: study

More information: A. M. P. von Bayern et al. Compound tool construction by New Caledonian crows, Scientific Reports(2018). DOI: 10.1038/s41598-018-33458-z 

Journal reference: Scientific Reports [Image: img-dot.gif] [Image: img-dot.gif]
Provided by: University of Oxford



Read more at: https://phys.org/news/2018-10-caledonian-crows-tools-multiple.html#jCp
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#24
Goffin's cockatoos can create and manipulate novel tools
November 7, 2018, Public Library of Science

[Image: goffinscocka.jpg]
A Goffin cockatoo tears off a strip of cardboard. Credit: Goffin Lab, University of Veterinary Medicine Vienna
Goffin's cockatoos can tear cardboard into long strips as tools to reach food—but fail to adjust strip width to fit through narrow openings, according to a study published November 7, 2018 in the open-access journal PLOS ONE by A.M.I. Auersperg from the Medical University of Vienna, Austria, and colleagues.




The Goffin's cockatoo (Cacatua goffiniana) is a type of parrot. Captive Goffins are capable of inventing and manipulating tools, even though they aren't known to use tools habitually. The authors of the present study investigated two questions: do Goffins adjust tool properties to save effort, and if so, how accurately can they adjust tool dimensions for the task? The authors supplied six adult cockatoos with large cardboard sheets to tear into strips as tools for the testing apparatus: a food platform with a food reward set at varying distances (4-16cm) behind a small opening which also varied in width (1-2cm).

They found that the Goffins were capable of adjusting the length of their cardboard strip tools to account for variations in food distance, making shorter tools when the reward was closer than when it was set farther away. In every case, if a first-attempt tool was too short, the second-attempt tool would be significantly longer. On average, all six birds made significantly longer tools than were required to reach the reward in all test conditions, with the birds tending to make increasingly long tools as the study progressed—perhaps as a risk-avoidance strategy.

[Image: 1-goffinscocka.jpg]
A Goffin cockatoo uses a cardboard tool to obtain food. Credit: Goffin Lab, University of Veterinary Medicine Vienna
However, only one bird was able to make a sufficiently-narrow tool to successfully reach the food reward when the opening was at its narrowest. The authors hypothesize that the shearing technique the birds use to tear the cardboard limits the narrowness of the resulting strips. The authors suggest that future studies provide less restrictive materials to assess whether Goffins are cognitively capable of adjusting tool width in this situation.

Alice Auersperg adds: "The way they inserted and discarded manufactured pieces of specific lengths differently depending on condition suggests that the cockatoos could indeed adjust their tool making behavior in the predicted direction but with some limits in accuracy. "

[Image: 1x1.gif] Explore further: Cockatoos keep their tools safe

More information: Auersperg AMI, Köck C, O'Hara M, Huber L (2018) Tool making cockatoos adjust the lengths but not the widths of their tools to function. PLoS ONE13(11): e0205429. doi.org/10.1371/journal.pone.0205429 

Journal reference: PLoS ONE
Provided by: Public Library of Science



Read more at: https://phys.org/news/2018-11-goffin-coc...s.html#jCp



A Trhybrid???

Discovery: Rare three-species hybrid warbler
November 7, 2018, Cornell University

[Image: discoveryrar.jpg]
Rare triple-hybrid warbler (Golden-winged Warbler, Blue-winged Warbler, and Chestnut-sided Warbler). Credit: Lowell Burket
Scientists have shown that a bird found in Pennsylvania is the offspring of a hybrid warbler mother and a warbler father from an entirely different genus—a combination never recorded before now and which resulted in a three-species hybrid bird. This finding has just been published in the journal Biology Letters.




"It's extremely rare," explains lead author and Cornell Lab of Ornithology postdoctoral associate David Toews. "The female is a Golden-winged/Blue-winged Warbler hybrid—also called a Brewster's Warbler. She then mated with a Chestnut-sided Warbler and successfully reproduced."

A dedicated bird watcher and contributor to eBird.org in Roaring Spring, Pennsylvania, first noted the oddity in May 2018. Lowell Burket says he spends time birding and relaxing in the woods on family-owned property where he also likes to take photos and video of birds. In one piece of video he noticed a male bird that sang like a Chestnut-sided Warbler but had some of the physical characteristics of both Blue-winged and Golden-winged Warblers. Burket saw the bird again a number of times, reported it to eBird, and got in touch with researchers in the Cornell Lab's Fuller Evolutionary Biology Lab.

"I tried to make the email sound somewhat intellectual so they wouldn't think I was a crackpot," Burket recalls. "Having the photos and video helped. Within a week researcher David Toews came down. We found the bird again and collected a blood sample and measurements. It was a very interesting and exciting morning for us. A few days later I got a text message from Dave saying, 'You were right!!!'"

[Image: 1-discoveryrar.jpg]
Rare triple-hybrid warbler (Golden-winged Warbler, Blue-winged Warbler, and Chestnut-sided Warbler). Credit: Lowell Burket
The key to identifying the triple-hybrid's parents came from genetic analyses.

"We looked at the genes that code for different warbler colors," Toews explains. "This way we could recreate what the hybrid's mother would have looked like—the avian equivalent of a detective's facial composite, but generated from genes. We confirmed that the mother would have looked like a Brewster's Warbler and the father was a Chestnut-sided Warbler."

Hybridization is common among Golden-winged and Blue-winged Warblers, and this has been of particular concern for Golden-winged Warblers which have declined dramatically in some populations. But hybridization has never been recorded between these species and Chestnut-sided Warblers. This kind of rare hybridization event may also occur more often in the declining warbler populations of Appalachia, because there is a smaller pool of mates from which to choose.





[Image: 2-discoveryrar.jpg]
Graphic shows predicted family tree of warblers leading to the three-species hybrid. Blue-winged, Golden-winged, and Brewster's Warblers by Liz Clayton Fuller; Chestnut-sided Warbler from del Hoyo et al. (2018) Handbook of the Birds of the …more"That this hybridization occurred within a population of Golden-winged Warblers in significant decline suggests that females may be making the best of a bad situation," says Toews. "It also tells us that wood-warblers in general have remained genetically compatible long after they evolved major differences in appearance."


Will the bird's mixed ancestry confuse potential mates and make him a pariah or will he be able to find a mate and successfully produce offspring? Scientists are going to keep an eye on this location to see what the future may hold for this very rare bird. And Lowell Burket declares he's a bird watcher for life.

"I had literally zero knowledge about birds until seven years ago," he says. "And now I end up discovering what appears to be a first-of-its-kind bird. It can happen to anybody!"

[Image: 1x1.gif] Explore further: Manitoba's golden-winged warblers: world's last pure population touched by local and distant conservation problems

More information: David P. L. Toews et al, A wood-warbler produced through both interspecific and intergeneric hybridization, Biology Letters (2018). DOI: 10.1098/rsbl.2018.0557 

Journal reference: Biology Letters [Image: img-dot.gif] [Image: img-dot.gif]
Provided by: Cornell University



Read more at: https://phys.org/news/2018-11-discovery-rare-three-species-hybrid-warbler.html#jCp
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#25
Rare fossil bird deepens mystery of avian extinctions
November 13, 2018, University of California - Berkeley

[Image: rarefossilbi.jpg]
Reconstruction of a living Mirarce eatoni perched on the horns of the ceratopsian dinosaur Utahceratops gettyi, animals that were alive in Utah during the Late Cretaceous (75 million years ago). Credit: paleoartist Brian Engh (dontmesswithdinosaurs.com)
During the late Cretaceous period, more than 65 million years ago, birds belonging to hundreds of different species flitted around the dinosaurs and through the forests as abundantly as they flit about our woods and fields today.




But after the cataclysm that wiped out most of the dinosaurs, only one group of birds remained: the ancestors of the birds we see today. Why did only one family survive the mass extinction?

A newly described fossil from one of those extinct bird groups, cousins of today's birds, deepens that mystery.

The 75-million-year-old fossil, from a bird about the size of a turkey vulture, is the most complete skeleton discovered in North America of what are called enantiornithines (pronounced en-an-tea-or'-neth-eens), or opposite birds. Discovered in the Grand Staircase-Escalante area of Utah in 1992 by University of California, Berkeley, paleontologist Howard Hutchison, the fossil lay relatively untouched in University of California Museum of Paleontology at Berkeley until doctoral student Jessie Atterholt learned about it in 2009 and asked to study it.

Atterholt and Hutchison collaborated with Jingmai O'Conner, the leading expert on enantiornithines, to perform a detailed analysis of the fossil. Based on their study, enantiornithines in the late Cretaceous were the aerodynamic equals of the ancestors of today's birds, able to fly strongly and agilely.

"We know that birds in the early Cretaceous, about 115 to 130 million years ago, were capable of flight but probably not as well adapted for it as modern birds," said Atterholt, who is now an assistant professor and human anatomy instructor at the Western University of Health Sciences in Pomona, California. "What this new fossil shows is that enantiornithines, though totally separate from modern birds, evolved some of the same adaptations for highly refined, advanced flight styles."

The fossil's breast bone or sternum, where flight muscles attach, is more deeply keeled than other enantiornithines, implying a larger muscle and stronger flight more similar to modern birds. The wishbone is more V-shaped, like the wishbone of modern birds and unlike the U-shaped wishbone of earlier avians and their dinosaur ancestors. The wishbone or furcula is flexible and stores energy released during the wing stroke.



If enantiornithines in the late Cretaceous were just as advanced as modern birds, however, why did they die out with the dinosaurs while the ancestors of modern birds did not?

"This particular bird is about 75 million years old, about 10 million years before the die-off," Atterholt said. "One of the really interesting and mysterious things about enantiornithines is that we find them throughout the Cretaceous, for roughly 100 million years of existence, and they were very successful. We find their fossils on every continent, all over the world, and their fossils are very, very common, in a lot of areas more common than the group that led to modern birds. And yet modern birds survived the extinction while enantiornithines go extinct."

One recently proposed hypothesis argues that the enantiornithines were primarily forest dwellers, so that when forests went up in smoke after the asteroid strike that signaled the end of the Cretaceous—and the end of non-avian dinosaurs—the enantiornithines disappeared as well. Many enantiornithines have strong recurved claws ideal for perching and perhaps climbing, she said.

"I think it is a really interesting hypothesis and the best explanation I have heard so far," Atterholt said. "But we need to do really rigorous studies of enantiornithines' ecology, because right now that part of the puzzle is a little hand-wavey."

Atterholt, Hutchison and O'Connor, who is at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, China, published an analysis of the fossil today in the open-access journal PeerJ.

Theropod dinosaurs evolved into birds

All birds evolved from feathered theropods—the two-legged dinosaurs like T. rex—beginning about 150 million years ago, and developed into many lineages in the Cretaceous, between 146 and 65 million years ago.

[Image: 1-rarefossilbi.jpg]
Skeletal reconstruction of Mirarce eatoni, an extinct bird that lived in Utah about 75 million years ago. Mirarce was a very large, strong flier. Credit: Scott Hartman (skeletaldrawing.com)
Hutchison said that he came across the fossil eroding out of the ground in the rugged badlands of the Kaiparowits formation in the Grand Staircase-Escalante National Monument in Garfield County, Utah, just inside the boundary of the recently reduced monument. Having found bird fossils before, he recognized it as a late Cretaceous enantiornithine, and a rare one at that. Most birds from the Americas are from the late Cretaceous (100-66 million years ago) and known only from a single foot bone, often the metatarsus. This fossil was almost complete, missing only its head.

"In 1992, I was looking primarily for turtles," Hutchison said. "But I pick up everything because I am interested in the total fauna. The other animals they occur with tells me more about the habitat."

According to Hutchison, the area where the fossil was found dates from between 77 and 75 million years ago and was probably a major delta, like the Mississippi River delta, tropical and forested with lots of dinosaurs but also crocodiles, alligators, turtles and fish.

Unlike most bird fossils found outside America, in particular those from China, the fossil was not smashed flat. The classic early Cretaceous bird, Archaeopteryx, was flattened in sandstone, which preserved a beautiful panoply of feathers and the skeletal layout. Chinese enantiornithines, mostly from the early Cretaceous, are equally beautiful and smashed flatter than a pancake.

"On one hand, it's great—you get the full skeleton most of the time, you get soft tissue preservation, including feathers. But it also means everything is crushed and deformed," she said. "Not that our fossils have zero deformation, but overall most of the bones have really beautiful three-dimensional preservation, and just really, really great detail. We see places where muscles and tendons were attaching, all kinds of interesting stuff to anatomists."

Once Hutchison prepared the fossils and placed them in the UC Museum of Paleontology collection, they drew the attention of a few budding and established paleontologists, but no one completed an analysis.

"The stuff is legendary. People in the vertebrate paleontology community have known about this thing forever and ever, and it just happened that everyone who was supposedly working on it got too busy and it fell by the wayside and just never happened," Atterholt said. "I was honored and incredibly excited when Howard said that I could take on the project. I was over the moon."

Her analysis showed that by the late Cretaceous, enantiornithines had evolved advanced adaptations for flying independent of today's birds. In fact, they looked quite similar to modern birds: they were fully feathered and flew by flapping their wings like modern birds. The fossilized bird probably had teeth in the front of its beak and claws on its wings as well as feet. Some enantiornithines had prominent tail feathers that may have differed between male and female and been used for sexual display.

"It is quite likely that, if you saw one in real life and just glanced at it, you wouldn't be able to distinguish it from a modern bird," Atterholt said.

This fossil bird is also among the largest North American birds from the Cretaceous; most were the size of chickadees or crows.

"What is most exciting, however, are large patches on the forearm bones. These rough patches are quill knobs, and in modern birds they anchor the wing feathers to the skeleton to help strengthen them for active flight. This is the first discovery of quill knobs in any enantiornithine bird, which tells us that it was a very strong flier."

Atterholt and her colleagues named the species Mirarce eatoni (meer-ark'-ee ee-tow'-nee). Mirarce combines the Latin word for wonderful, which pays homage to "the incredible, detailed, three-dimensional preservation of the fossil," she said, with the mythical Greek character Arce, the winged messenger of the Titans. The species name honors Jeffrey Eaton, a paleontologist who for decades has worked on fossils from the Kaiparowits Formation. Eaton first enticed Hutchison to the area in search of turtles, and they were the first to report fossils from the area some 30 years ago.

Thousands of such fossils from the rocks of the Kaiparowits Formation, many of them dinosaurs, contributed to the establishment of the Grand Staircase-Escalante National Monument in 1996.

"This area contains one of the best Cretaceous fossil records in the entire world, underscoring the critical importance of protecting and preserving these parts of our natural heritage," Atterholt said. "Reducing the size of the protected area puts some of our nation's most valuable natural and scientific resources at risk."

 Explore further: First fossil bird with teeth specialized for tough diet

More information: Atterholt et al. (2018), The most complete enantiornithine from North America and a phylogenetic analysis of the Avisauridae. PeerJ 6:e5910; DOI: 10.7717/peerj.5910 , peerj.com/articles/5910 

Journal reference: PeerJ 
Provided by: University of California - Berkeley



Read more at: https://phys.org/news/2018-11-rare-fossi...y.html#jCp


Quote:Saturday, November 25th, 2017, 06:33 pm (This post was last modified: Saturday, November 25th, 2017, 06:52 pm by Fsbirdhouse.)
Got into a discussion with a fellow about Noah's Ark being able to hold all the animals needed to repopulate the earth after the Great Flood of Biblical fame.
Arrow  Read more at: https://phys.org/news/2018-11-rare-fossi...y.html#jCp
He pointed out rightly, that there were millions and millions of species of creatures (by any reckoning) prior to the Great Flood, and that all of them could not have fit in a barge of even so great dimensions.

Thatz the Beauty of Noah's Ark-a-types(there are many tellings of the tale).

But noah wasn't around 65 mya.

~11,000 yag...that makes common sense.  Arrow

How the house sparrows came to be

October 2, 2018, University of Oslo



[Image: 5bb36a43b0b0a.jpg]
One of the authors of the study, Cassandra Trier, releases a Bactrianus sparrow caught in Kazakhstan. Credit: University of Oslo
House sparrows are closely associated with humans and are found in most parts of the world. By investigating the DNA of several species of sparrows, researchers have shown that the house sparrow diverged from a sparrow in the Middle East – and started to digest starch-rich foods – when humans developed agriculture some 11,000 years ago.




The house sparrow (Passer domesticus), is a very familiar bird species. If you walk down the street of any major European town or city, you will see them hopping back and forth, picking up scraps of food and nesting in nearby buildings. They are also a common sight on farms and in the countryside. Our connection with sparrows goes further – they are mentioned in the Bible, in Chaucer's The Canterbury Tales and Shakespeare's Hamlet.



How is it that this small, charismatic bird has become so closely associated with us?



Researchers at the Centre for Ecological and Evolutionary Synthesis (CEES) at the University of Oslo (UiO) have been trying to answer this question by investigating the DNA of populations of house sparrows from across Europe and the Middle East. Teaming up with colleagues from Iran and Kazakhstan, they also investigated the Bactrianus sparrow, a subspecies found only in these regions.



The Bactrianus sparrow looks like a house sparrow, but is wild, avoids human contact and feeds on a very different diet. By comparing the DNA of the two sparrows, the team hoped to gain some insight into why one evolved to be closely associated with people while the other did not.



House sparrows came with the birth of agriculture



"Our findings suggest the house sparrows and Bactrianus sparrows probably diverged from each other about 11,000 years ago, around time that humans were developing agriculture in the Middle East," says researcher Mark Ravinet to Titan.uio.no.







[Image: 5bb36a51d3f94.jpg]

Field work on the steppes in Kazakhstan is an experience to be remembered. Credit: University of Oslo"We also found evidence that the number of house sparrows greatly increased around 6000 years ago" he adds, speaking about a new paper from the team, published recently in the scientific journal Proceedings of the Royal Society of London B. This ties in well with previous suggestions that the movement of house sparrows into Europe was closely associated with the spread of early agriculture.





A close association with humans has had a profound effect on house sparrows. Earlier work by the team has shown that hybridization and gene exchange between the house sparrow and Spanish sparrow (Passer hispaniolensis) gave rise to the Italian sparrow (Passer italiae) in the Mediterranean. This likely occurred when house sparrows moved into Europe alongside early agriculturalists. But now the team have also identified evidence that suggests house sparrows have evolved specific adaptations to life alongside humans.







Adapting to an agriculture-based diet



"We found several genes which have experienced strong recent natural selection in the house sparrow," says Ravinet.



These include two genes right next to each other; one involved in skull formation and the other involved in starch digestion.



"The skull gene is interesting because we know that the house sparrow skulls and the Bactrianus sparrow skulls differ in shape," Ravinet explains, "but we were really excited to see the digestion gene there too."



Interestingly, this gene is closely related to genes which help both humans and dogs digest starch too and are thought to have helped them adapt to an agriculture-based diet. It seems then that just as the house sparrow has had an influence on our culture, we have played a role in shaping its biology. "We still have some way to go to investigate this further," says Ravinet, "but it is exciting to think that the evolution of a species so familiar to us is tightly linked to a major event in the development of modern human civilization."



[Image: 1x1.gif] Explore further: Hybridization can give rise to different genome combinations



More information: Mark Ravinet et al. Signatures of human-commensalism in the house sparrow genome, Proceedings of the Royal Society B: Biological Sciences(2018). DOI: 10.1098/rspb.2018.1246 



Journal reference: Proceedings of the Royal Society B [Image: img-dot.gif][Image: img-dot.gif]
Provided by: University of Oslo





Read more at: https://phys.org/news/2018-10-house-sparrows.html#jCp


[/url]How the house sparrow made its home with humans | Science | AAAS


https://www.sciencemag.org/news/2018/......home-human...




Aug 24, 2018 - The house sparrow's closeness to humans might have changed its genes, .... By Erik Stokstad Nov. 12, 2018. Hugh and Chris Hempel with their ...
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#26
Hemimastigotes found to represent a major new branch on evolutionary tree of life
November 15, 2018 by Bob Yirka, Phys.org report

[Image: 2-evolution.jpg]
Credit: CC0 Public Domain
A team of researchers at Dalhousie University has found evidence that suggests hemimastigotes represent a major new branch of evolutionary life. In their paper published in the journal Nature, the group describes their genetic study of the dirt-dwelling microbe.




The researchers note that hemimastigotes have been known to scientists since the 19th century, but it was not until very recently that technology has allowed scientists to learn how different they are from other eukaryotic life forms. The researchers report that one of their team members, Yana Eglit, had been digging in a local park just outside of Halifax. Intrigued by the microbes she found in the dirt, she isolated a group that appeared to be hemimastigotes. After letting the microbes reproduce in a small dish filled with nothing but dirt and water for a month, she collected samples that the team used to conduct a genetic analysis.

The researchers report that the hemimastigotes are so different from anything observed before that fungi and animals are actually more closely related. They describe the microbes as being approximately two-hundredths of a millimeter long—they move using over a dozen flagella. And they survive by eating other microbes. It was the latter characteristic that led the team to name the species Hemimastix kukwesjijk, in honor of a hairy man-eating ogre from Mi'kmaq (native people in Nova Scotia) folklore.

The researchers describe hemimastigotes as representing a major new branch on the evolutionary tree—standing above the level of a kingdom. The team was able to analyze hundreds of samples, thanks to Eglit's efforts in getting them to reproduce, which provided a very clear understanding of the genetic makeup of the microbes. They also suggest their findings fill some evolutionary holes in the tree of life. They also note that in addition to learning about how different hemimastigotes truly are from other life forms, the work by Eglit also offers a lesson for other researchers in how to grow such species in large enough volume to allow for such thorough study.

[Image: 1x1.gif] Explore further: Long-term study shows atmospheric biome fluctuates by season

More information: Gordon Lax et al. Hemimastigophora is a novel supra-kingdom-level lineage of eukaryotes, Nature (2018). DOI: 10.1038/s41586-018-0708-8 

Journal reference: Nature


Read more at: https://phys.org/news/2018-11-hemimastig...e.html#jCp




[Image: 5bed7f95d59d7.jpeg]

Songbirds set long-distance migration record
Researchers at Lund University in Sweden have studied flight routes to determine how far willow warblers migrate in the autumn. The results show that the willow warbler holds a long-distance migration record in the ten-gram ...



[Image: 1-evolution.jpg]

Zoologist outlines how humans have altered evolution over past century
Zoologist Sarah Otto, with the University of British Columbia, has published a report in the journal Proceedings of the Royal Society B regarding human influence on evolution over the past century. She notes that the number ...
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#27
RE: A little bird told me... a funny story of evolution.


Tiny raptor tracks lead to big discovery
November 16, 2018, University of Queensland

[Image: tinyraptortr.jpg]
Dinosaur reconstructions by Dr Anthony Romilio. Credit: University of Queensland
Tracks made by dinosaurs the size of sparrows have been discovered in South Korea by an international team of palaeontologists.




University of Queensland researcher Dr. Anthony Romilio was part of the team which described the tracks, which were originally found by Professor Kyung Soo Kim from Chinju National University of Education, South Korea.

"These 110-million-year-old footprints and trackways were made by carnivorous dinosaurs commonly known as raptors," Dr. Romilio said.

"These new tracks are just one centimetre in length, which means the dinosaur that made them was an animal you could have easily held in your hand.

"They are the world's smallest dinosaur tracks."

To estimate the size of the dinosaur that made the tracks, the team measured the footprint length and multiplied the value by 4.5 to get an approximate hip height.

"The diminutive sizes of these new tracks are extraordinary; the tracks were made by tiny dinosaurs about the size of sparrows," Dr. Romilio said.

"Raptors placed only two of their toes on the ground, while the third toe was retracted like a cat's claw."

The research team are unsure if the tracks were made by a small adult species, or baby dinosaurs.




Credit: University of Queensland"Very small dinosaur species like the Chinese Microraptor were crow-sized, but these had feet too large to match the South Korean footprints," Dr. Romilio said.


"If the tracks were made by dinosaur chicks, we are unclear as to the specific dinosaur that made them, since dinosaurs such as Velociraptor and Utahraptor had larger feet then the ones discovered in these new tracks."

Professor Kim said the Cretaceous lake deposits at the discovery site created perfect conditions that allowed for the preservation of tiny footprints rarely found elsewhere.

"In addition to tiny dinosaur tracks, we have footprints made by birds, pterosaurs, lizards, turtles, mammals, and even frogs," he said.

"We have named these small tracks Dromaeosauriformipes rarus, which means rare footprints made by a member of the raptor family known as dromaeosaurs," Professor Kim said.

The research is published in Scientific Reports and included scientists from South Korea, the United States, China, Spain and Australia.

Explore further: High–tech imaging stamps on Queensland dinosaur stampede theory

More information: Kyung Soo Kim et al. Smallest known raptor tracks suggest microraptorine activity in lakeshore setting, Scientific Reports (2018). DOI: 10.1038/s41598-018-35289-4 

Journal reference: Scientific Reports
Provided by: University of Queensland



Read more at: https://phys.org/news/2018-11-tiny-raptor-tracks-big-discovery.html#jCp


Quote:After examining the genes, vonHoldt discovered that the "mega" is genetically distinct from the small- and large-beaked morphs. Not only does it carry two copies of the large allele—like the large-beaked finches—but it also has other chromosomal changes, apparently the product of an additional evolutionary step.
[Image: hqdefault.jpg] "Itza IGF-1"
Geneticists solve long-standing finch beak mystery
November 19, 2018, Princeton University

[Image: princetongen.jpg]
Black-bellied seedcrackers (Pyrenestes ostrinus) can have large (right) or small beaks on birds of the same size, a trait that had mystified researchers for years. Princeton biologist Bridgett vonHoldt found that the two morphs differ in a …more
Bridgett vonHoldt is best known for her work with dogs and wolves, so she was surprised when a bird biologist pulled her aside and said, "I really think you can help me solve this problem." So she turned to a mystery he'd been wrestling with for more than 20 years.




"I love a good challenge and especially working on new questions!" said vonHoldt, an assistant professor of ecology and evolutionary biology at Princeton. "I was presented with a new problem in an entirely new system, which was an incredible opportunity to explore how different ecologies could promote different evolutionary patterns."

The birder and biologist was Tom Smith, who has spent his career studying finches—specifically, black-bellied seedcrackers (Pyrenestes ostrinus)—in Cameroon and in his lab at the University of California-Los Angeles.

He and his colleagues have spent years investigating why some of these finches have small beaks while others have large beaks. Much of their original work identified differences in the hardness of the seeds they eat, a story quite similar to that of Darwin's finches. Smith, who is a professor at UCLA as well as the founding director of the Center for Tropical Research, established a breeding colony of these finches to understand the inheritance of beak size.

The result was startlingly and elegantly simple: Mendelian genetics, best known to generations of high school students through Punnett squares. The larger beak was the dominant trait, so two small-billed parents could only have small-billed offspring, but if either parent had a large bill, their offspring would have a mix of large and small bills, perfectly matching the 3:1 pattern predicted by Gregor Mendel centuries ago.



[Image: 1-princetongen.jpg]
Princeton biologist Bridgett vonHoldt discovered that the 'mega' morph of the black-bellied seedcrackers (Pyrenestes ostrinus), a Cameroonian finch, appears to result from an additional evolutionary step after the evolution of the large- and small-beaked morphs. Credit: Dr. Tom Smith, UCLA

"You never get this!" said vonHoldt with a laugh. "Traits rarely show such a clean pattern of inheritance, especially traits that are very central to fitness in a wild population."


That Mendelian pattern was the key, said vonHoldt. With new technology to analyze the entire genome, combined with the Smith's years of ecological data and insights, they had all the pieces to find and understand the genes behind this mystery.

Smith had found the Mendelian pattern in these Cameroonian birds through observation, but he hadn't been able to identify the gene responsible for it. But when vonHoldt compared the genes of the large-beaked birds to those of their smaller-beaked counterparts, she found one stretch of DNA—300,000 base pairs, apparently inherited as a chunk—that always varied between finches of large and small beak size. And right in the middle of that piece of chromosome was the gene IGF-1, familiar to vonHoldt from canine genetics.



"In dogs, this is a giant gene, literally and figuratively," she said. "It's a growth-factor gene. In dogs, if you change how it's expressed, with just a few genetic changes you can change a normal-sized dog into a dwarfed, teacup-sized dog."

The gene can affect a specific trait or a whole animal, depending where it's located on the genome and when it is expressed. "If this gene is expressed more, you expect a larger trait: a larger body, a larger foot, a larger ear, whatever it is controlling. It then is easy to imagine that with a small change to this gene, traits could very easily change in size or shape. We suspect this is the story here, with these beaks," vonHoldt said.

[Image: 2-princetongen.jpg]
Princeton biologist Bridgett vonHoldt, seen here with her dog Marla, branched out from her usual field of canine genetics to tackle a bird mystery: Why does a species of Cameroonian finches have two beak sizes? Credit: Chris Fascenelli, Princeton University

Smith and his colleagues had already determined that beak size affected diet—whether a finch lived on large or small seeds—but it didn't seem to have any impact on mate selection. "Females don't prefer males with a large beak, or vice-versa," said vonHoldt.

In these birds, the bill was the only trait changing size; large-beaked and small-beaked black-bellied seedcrackers are otherwise identical. But Smith also discovered a third morph of these finches, which he called the "mega" variety, with an even bigger bill and a larger overall body size.

After examining the genes, vonHoldt discovered that the "mega" is genetically distinct from the small- and large-beaked morphs. Not only does it carry two copies of the large allele—like the large-beaked finches—but it also has other chromosomal changes, apparently the product of an additional evolutionary step.

VonHoldt said she appreciated the opportunity to branch out from her usual subjects. "Dogs and wolves have helped me ask the questions I find exciting, from domestication to conservation," she said, such as her work with the wolves in Yellowstone National Park. "There is so much to explore beyond canines. This was a great opportunity to make new collaborations, think about a different problem and use new methods to tackle an old question."

Explore further: Evolution in action detected in Darwin's finches

More information: Bridgett M. vonHoldt et al, Growth factor gene IGF1 is associated with bill size in the black-bellied seedcracker Pyrenestes ostrinus, Nature Communications (2018). DOI: 10.1038/s41467-018-07374-9 

Journal reference: Nature Communications
Provided by: Princeton University



Read more at: https://phys.org/news/2018-11-geneticist...y.html#jCp



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Jumping genes shed light on how advanced life may have emerged
A previously unappreciated interaction in the genome turns out to have possibly been one of the driving forces in the emergence of advanced life, billions of years ago.
[Image: 1x1.gif]43 minutes ago in Evolution Cell & Microbiology Molecular & Computational Biology
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#28
Embryological study of the skull reveals dinosaur-bird connection
November 20, 2018, Universidad de Chile

[Image: 5bf3f8f8c167a.jpg]
Birds evolved from dinosaurs, radically transforming their skull as it became toothless and the brain grew bigger. The large dinosaur with a dark outline in the image is Erlikosaurus; below, the modern seabird Sula. During evolution, birds lost two of the skull bones once present in dinosaurs: The prefrontal, and the postorbital. However, during the embryonic development of birds, starting points for the formation of these bones are still present. The dark circles above illustrate the appearance of these embryonic bones under the microscope, as revealed by a purple stain that is bone-specific (alizarin red). The embryonic prefrontal and postorbital later fuse to other embryonic bones, becoming undetectable in the adult. Credit: Luis Pérez López [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)], from Wikimedia Commons


Birds are the surviving descendants of predatory dinosaurs. However, since the likes of Tyrannosaurus and Velociraptor, some parts of their anatomy have become radically transformed. The skull, for instance, is now toothless, and accommodates much larger eyes and brain. Skulls are like 3-D puzzles made of smaller bones: As the eye socket and brain case expanded along evolution, birds lost two bones of the skull that were once present in dinosaurs -the prefrontal, at the upper front corner of the eye, and the postorbital, behind the eye (See the skull of Erlikosaurus compared to the seabird Sula in the image below).




Or rather, this seemed to be the case.
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 A new study published in Nature Ecology & Evolution has uncovered how during embryonic development of the bird skull, both of these dinosaur bones are still present as starting points of bone formation (ossification centers). Rather than becoming independent bones of the adult skull (as in ancient predatory dinosaurs), they fuse quickly to other embryonic bones, becoming undetectable in the adult bird. 
[Image: source.gif]

The study is the master's thesis of evolutionary biologist Daniel Smith.

During the evolution of toothed, dinosar-like birds in the Cretaceous period, the disappearance of the adult postorbital coincided with an increase in size of the brain, as well as the frontal bone above the brain. The new study shows how the embryonic postorbital of birds fuses to the frontal, becoming part of that bone. By adding itself to the frontal, the postorbital could have allowed it to expand and accommodate a larger brain in evolution. This discovery has also unraveled a long-standing mystery of embryology: In most animals, the frontal bone is formed from cells coming from the outer layer of the early embryo, called the ectoderm. Birds are very unusual because their frontal bone develops from two sources of embryonic cells: The front portion is formed from the ectoderm, but the back portion is formed from an inner layer of the embryo, called the mesoderm. The reason for this was enigmatic, but some scientists had suggested that the back portion of the frontal was different because it evolved from a different bone, that became assimilated into the frontal. The new study has confirmed this hypothesis, by showing that the back portion of the frontal actually starts out as a separate embryonic bone, the same that once developed into the postorbital of dinosaurs (see the image of duck embryos below).

[Image: 5bf3f905be1e8.jpg]
These images of duck embryos show how the postorbital is at a first a separate embryonic bone (above), the same that in dinosaurs became a separate bone of the adult skull. At a later stage, the embryonic postorbital fuses to the frontal, …more
Professor Bhart-Anjan Bhullar at Yale University (who was not part of the study) summarizes the work of his colleagues: "Smith-Paredes et al. have discovered dinosaurian vestiges hidden in the embryonic skull of birds, and in so doing have presented an elegant solution to the question of why the avian frontal bone is a composite structure: it incorporates other bones thought lost during the dinosaur-bird transition. 


Therefore, evolution has worked in a graceful, elegant way —by subtly removing seams and fusing existing building blocks —to build something remarkably divergent and unique."
[Image: WindyFondJay-small.gif]


The Vargas lab has previously studied how parts of the embryonic wrist, shank and foot also show a general dinosaur pattern, before developing an anatomy that is specific to birds. The new study provides further evidence for the "inner dinosaur" of birds, in the sense that much of their embryology is still the same as in their ancient ancestors.

Explore further: Birds' unique skulls linked to young dinosaur brains

More information: Daniel Smith-Paredes et al. Dinosaur ossification centres in embryonic birds uncover developmental evolution of the skull, Nature Ecology & Evolution (2018). DOI: 10.1038/s41559-018-0713-1 

Journal reference: Nature Ecology & Evolution
Provided by: Universidad de Chile



Read more at: https://phys.org/news/2018-11-embryological-skull-reveals-dinosaur-bird.html#jCp
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[Image: tumblr_oi8i5xLZEq1ufvrblo5_400.gif] dino-descendants...

meet dino-precedents...  Arrow

Three ancient skeletons, ancestors of giant dinosaurs, unearthed in Brazil
November 21, 2018 by Bob Yirka, Phys.org report

[Image: threeancient.jpg]
Reconstructed skeleton and representative elements of Macrocollum itaquii. (a) Skull in left lateral view (CAPPA/UFSM 0001a). (b) Skull in dorsal view (CAPPA/UFSM 0001a). © Skull in ventral view (CAPPA/UFSM 0001b). (d) Fourth cervical …more


A trio of researchers, two with Universidade Federal de Santa Maria, the other Universidade de São Paulo, have unearthed the remains of three early ancestors of the giant dinosaurs that would later roam the Earth. In their paper published in the journal Biology Letters, Rodrigo Temp Müller, Max Cardoso Langer and Sérgio Dias-da-Silva describe the three complete and very well-preserved dinosaur skeletons they uncovered in a southern part of Brazil.




The skeletal remains have been dated to approximately 225 million years ago, putting them in the Late Triassic, or more specifically, the Norian. The researchers note that they were much smaller than their descendants, standing just five feet tall and weighing approximately 200 pounds—their heads were small enough to be held by a human hand. The remains represent a new species of dinosaur—they have been named Macrocollum itaquii, and are members of a clad made up of other members of the Gondwanan Triassic taxa. They were vegetarian and had very long necks, which allowed them to reach up for higher food sources. They also walked on just two legs. The dinosaurs trod the Earth during the time when Brazil was still a part of the supercontinent Pangaea.

Prior research has shown that the most dominant type of vegetation during the Late Triassic was gymnosperms (plants with no flowers that produced seeds and cones) and ferns. A long neck would have allowed the dinosaurs to reach higher than other creatures that lived during the same time period, giving them an obvious advantage.

The researchers report that the skeletal remains were found very close together inside five tons of rock and that they were very well preserved. They suggest that the fact that they died together indicates that they likely also lived together, evidence that the early dinosaurs were social creatures. They also suggest that the discovery of M. itaquii skeletal remains will fill in the evolutionary history of dinosaurs in general and sauropodomorphs in particular, perhaps explaining how their descendants grew so large. They note that fossils from early Norian rocks are quite scarce; thus, the find is likely to generate considerable interest in the archaeological community.

[Image: 1x1.gif] Explore further: Dinosaurs' rise was 'more gradual,' new fossil evidence suggests

More information: Rodrigo Temp Müller et al. An exceptionally preserved association of complete dinosaur skeletons reveals the oldest long-necked sauropodomorphs, Biology Letters (2018). DOI: 10.1098/rsbl.2018.0633 

Journal reference: Biology Letters


Read more at: https://phys.org/news/2018-11-ancient-skeletons-ancestors-giant-dinosaurs.html#jCp
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#30
Darwin's finches have developed a taste for junk food, and it may be impacting their evolution
December 5, 2018 by Umass Boston Office Of Communications, University of Massachusetts Boston

[Image: 1-darwinsfinch.jpg]
Finches eat from an egg crate left by the researchers. Credit: University of Massachusetts Boston
A UMass Boston professor and his colleagues have published new research showing that feeding on human junk food may be altering the course of evolution in Darwin's finches.




Assistant Professor of Evolutionary Biology Luis De León says feeding on human foods is weakening natural selection on ground finch beaks, which is what drives the formation of new species in the wild. These findings, published in the journal Evolutionary Applications, suggest that the seemingly harmless activity of feeding birds might be altering the course of evolution in the iconic Darwin's finches in the Galápagos islands.

"If we continue to feed finches, we're not only affecting the individual species, but the processes that lead to the formation of new species," De León said. "We're getting in the way of evolution."

Galápagos finches are famed for being the inspiration behind Charles Darwin's pioneering work on evolution. They are an example of adaptive radiation, an evolutionary process that produces new species from a single, rapidly diversifying lineage. Their common ancestor arrived on the Galápagos about two million years ago, and since then Darwin's finches have evolved into more than a dozen recognized species differing in body size, beak shape, and feeding behavior.

De León and fellow researchers from UMass Amherst, Universidad San Francisco de Quito, McGill University, and Norwegian University of Science and Technology were on Santa Cruz Island when they found two forms of medium ground finches—a small and large version—while studying beak size at an isolated, pristine site.

When they repeated the same set of measurements at a nearby urban site, the distinction between the two beak sizes was not present. Studying data collected by other researchers in the 1970s, the researchers could see the two types of medium ground finches had been present in the area before, but something had changed in the last 40-50 years.

They hypothesized that the change might have to do with urbanization and the rapidly increasing human population in that area. In particular, the introduction of novel foods brought by humans.

[Image: 2-darwinsfinch.jpg]
Assistant Professor of Evolutionary Biology Luis De León studies Darwin's finches. Credit: University of Massachusetts Boston
Using egg crates filled with natural seeds and human junk food—chips, cookies, and rice—the researchers tested to see if the finches were in fact feeding on human food and what their preference was, weighing the food before and after to see how much was eaten.



De León said they found that finches in the urban area were almost exclusively feeding on human food. When the experiment was repeated at an isolated site in nature, the finches ignored the trays.

They found that "urban" finches feed on human junk foods, and in fact prefer these foods over their natural diet. This indicates that ongoing urbanization in the Galápagos is eroding the ecological differences that originally drove the formation of species in Darwin's finches.

"In contrast to their natural diet, the finches are changing their diet to human junk food," De León said. "We know one way finches diversify and become new species is by specializing in different food types. All three or four species of ground finches at urban sites on Santa Cruz Island seem to be converging onto the same junk food diet. If that's the case, the selection pressures that would be naturally  keeping them apart would be weakening, possibly leading to the collapse of the adaptive radiation of ground finches."

Researchers also found a strong preference for human foods at EG Beach, a non-urban site visited by tourists located 12 kilometers away from the town of Puerto Ayora. This suggests that human behavior, rather than human population density, is the main driver of finches' preference for human food, expanding the impacts of urbanization beyond city centers.

Now that the researchers know that finches are changing their diets to human junk food, they need to look at the consequences for the actual evolution of the species on this island.

"When thinking about preserving biodiversity in general, we often focus on preserving individual species," he said. "What we show with this work is we also need to consider preserving the processes that lead to the formation of species."

[Image: 3-darwinsfinch.jpg]
Finches eat off a plate in an urban area of the Galapagos. Credit: K. Gotanda
De León and a PhD student will return to the Galapagos in January.

De León said they will continue to do more genetic analysis, looking at whether there is an increase in gene flow across the four species of ground finch. Now that the birds are eating the same diet, researchers want to know if they are also interbreeding.

Elaine Montes, a second-year PhD student at UMass Boston who is working with De León, will look at the physiological consequences of human junk food on Galapagos finches by analyzing telomeres, a long chain of repetitive DNA at the end of every chromosome that can shorten due to stress and aging.

"We want to see whether they have a shorter life span than birds in nature," he said.

De León has worked at UMass Boston for two years. He received his PhD at McGill University, where he started his work on Galapagos finches 14 years ago.

"It's a fascinating place. Every species is so unique; it captures your imagination. You can imagine how Darwin was fascinated by looking at all those species," he said. "I feel privileged to essentially walk in Darwin's footsteps."

[Image: 1x1.gif] Explore further: Epigenetics may explain how Darwin's finches respond to rapid environmental change

More information: Luis F. De León et al. Urbanization erodes niche segregation in Darwin's finches, Evolutionary Applications (2018). DOI: 10.1111/eva.12721 

Provided by: University of Massachusetts Boston


Read more at: https://phys.org/news/2018-12-darwin-fin...g.html#jCp








Medullary bone found in Cretaceous birds

December 5, 2018, Chinese Academy of Sciences

[Image: medullarybon.jpg]
Main slab of Pengornithid Enantiornithine, preserved in three-dimensions unlike most compression fossils from the Jehol Biota. Scale bar is one centimeter. Credit: Jingmai O'Connor
A team of scientists led by Jingmai O'Connor from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), Chinese Academy of Sciences, reported the first occurrence of medullary bone in Enantiornithes, the dominant clade of birds during the Cretaceous. The findings were published in Nature Communications on Dec. 5.




Medullary bone is a bone tissue unique to birds today. It is present only in females about to lay eggs and forms in the empty spaces within the skeleton. This bone tissue serves as a reservoir for calcium needed to form the eggshell.

Medullary bone has been reported in a variety of non-avian dinosaurs including Tyrannosaurus rex, ornithopod dinosaurs like Tenontosaurus, and several sauropods (huge long-necked dinosaurs) including Mussasaurus. It has also been identified in pterosaurs, which are flying reptiles closely related to dinosaurs.

Since the first report of medullary bone in a Mesozoic fossil in 2005, this tissue has attracted great interest because it links birds and dinosaurs. However, the presence of this bone tissue in pterosaurs and non-avian dinosaurs is perplexing. Non-avian dinosaurs were so large and their eggs so small that they shouldn't have required medullary bone. Since pterosaurs laid soft-shelled eggs, they also shouldn't have required medullary bone.

Some reported instances of medullary bone are probably actually bone pathologies causing abnormal growth. However, in this report, IVPP scientists, working together with Mark Norell from the American Museum of Natural History and Greg Erickson from Florida State University, argued that no previous description of medullary bone in a Mesozoic reptile was well supported.

[Image: 1-medullarybon.jpg]
Cross section of the femur bone viewed under polarized light showing the thick layer of medullary bone within the medullary cavity. Credit: Jingmai O'Connor
The new report is the best support for medullary bone in the Mesozoic so far since it was found throughout the entire preserved skeleton, suggesting it was part of a system-wide process rather than a local pathology. However, the authors concede that scientists still know too little about medullary bone to confirm, without additional evidence (e.g., association with a nest or eggs), that the fossilized individual with this tissue was reproductively active.

In light of the currently available evidence, medullary bone might have been an entirely avian feature even in the Mesozoic. It evolved as a result of the thinned, hollow bones in birds, which lightened the skeleton for flight, as well as their increased egg size.

[Image: 1x1.gif] Explore further: Pregnant T. rex could aid in dino sex-typing

More information: Jingmai O'Connor et al, Medullary bone in an Early Cretaceous enantiornithine bird and discussion regarding its identification in fossils, Nature Communications (2018). DOI: 10.1038/s41467-018-07621-z 

Journal reference: Nature Communications [Image: img-dot.gif] [Image: img-dot.gif]
Provided by: Chinese Academy of Sciences



Read more at: https://phys.org/news/2018-12-medullary-bone-cretaceous-birds.html#jCp
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#31
New discovery pushes origin of feathers back by 
Arrow  70 million years  Doh
December 17, 2018, University of Bristol

[Image: 10-newdiscovery.jpg]
A reconstruction of the studied Daohugou pterosaur, with four different feather types over its head, neck, body, and wings, and a generally ginger-brown color. Credit: Reconstruction by Yuan Zhang.
An international team of palaeontologists, which includes the University of Bristol, has discovered that the flying reptiles, pterosaurs, actually had four kinds of feathers, and these are shared with dinosaurs - pushing back the origin of feathers by some 70 million years.




Pterosaurs are the flying reptiles that lived side by side with dinosaurs, 230 to 66 million years ago. It has long been known that pterosaurs had some sort of furry covering often called 'pycnofibres', and it was presumed that it was fundamentally different to feathers of dinosaurs and birds.

In a new work published today in the journal Nature Ecology & Evolution, a team from Nanjing, Bristol, Cork, Beijing, Dublin, and Hong Kong show that pterosaurs had at least four types of feathers:
  • simple filaments ('hairs')

  • bundles of filaments,

  • filaments with a tuft halfway down

  • down feathers.
These four types are now also known from two major groups of dinosaurs - the ornithischians, which were plant-eaters, and the theropods, which include the ancestors of birds.

Baoyu Jiang of Nanjing University, who led the research, said: "We went to Inner Mongolia to do fieldwork in the Daohugou Formation.

"We already knew that the sites had produced excellent specimens of pterosaurs with their pycnofibres preserved and I was sure we could learn more by careful study."

[Image: 11-newdiscovery.jpg]
The four feather types: filaments, filament bunches, tufted filament, down feather. Scale bars for photos, are a-d: 100μm, 200μm, 500μm and 1mm). Credit: Zixiao Yang
Zixiao Yang, also of Nanjing University, has studied the Daohugou localities and the pterosaurs as part of his PhD work. He said: "This was a fantastic opportunity to work on some amazing fossils.

"I was able to explore every corner of the specimens using high-powered microscopes, and we found many examples of all four feathers."

Maria McNamara of University College Cork, added: "Some critics have suggested that actually there is only one simple type of pycnofibre, but our studies show the different feather types are real.

"We focused on clear areas where the feathers did not overlap and where we could see their structure clearly. They even show fine details of melanosomes, which may have given the fluffy feathers a ginger colour."

Professor Mike Benton from the University of Bristol's School of Earth Sciences, said: "We ran some evolutionary analyses and they showed clearly that the pterosaur pycnofibres are feathers, just like those seen in modern birds and across various dinosaur groups.





[Image: 5c17691d25c15.jpg]
Preservation, microstructure and chemistry of the fossilized filamentous structures. Credit: Baoyu Jiang, Michael Benton et al./Nature Ecology & Evolution"Despite careful searching, we couldn't find any anatomical evidence that the four pycnofibre types are in any way different from the feathers of birds and dinosaurs. Therefore, because they are the same, they must share an evolutionary origin, and that was about 250 million years ago, long before the origin of birds."


Birds have two types of advanced feathers used in flight and for body smoothing, the contour feathers with a hollow quill and barbs down both sides.

These are found only in birds and the theropod dinosaurs close to bird origins. But the other feather types of modern birds include monofilaments and down feathers, and these are seen much more widely across dinosaurs and pterosaurs.

The armoured dinosaurs and the giant sauropods probably did not have feathers, but they were likely suppressed, meaning they were prevented from growing, at least in the adults, just as hair is suppressed in whales, elephants, and hippos. Pigs are a classic example, where the piglets are covered with hair like little puppies, and then, as they grow, the hair growth is suppressed.

Professor Benton added: "This discovery has amazing implications for our understanding of the origin of feathers, but also for a major time of revolution of life on land.



[Image: 5c17692c76eac.jpg]
Phylogenetic comparative analysis of integumentary filament and feather evolution in pterosaurs and archosaurs. Credit: Baoyu Jiang, Michael Benton et al./Nature Ecology & Evolution"When feathers arose, about 250 million years ago, life was recovering from the devasting end-Permian mass extinction.


"Independent evidence shows that land vertebrates, including the ancestors of mammals and dinosaurs, had switched gait from sprawling to upright, had acquired different degrees of warm-bloodedness, and were generally living life at a faster pace.

"The mammal ancestors by then had hair, so likely the pterosaursdinosaurs and relatives had also acquired feathers to help insulate them.

"The hunt for feathers in fossils is heating up and finding their functions in such early forms is imperative. It can rewrite our understanding of a major revolution in life on Earth during the Triassic, and also our understanding of the genomic regulation of feathers, scales, and hairs in the skin."

 Explore further: Scientists discover how birds and dinosaurs evolved to dazzle with colourful displays

More information: Zixiao Yang et al. Pterosaur integumentary structures with complex feather-like branching, Nature Ecology & Evolution (2018). DOI: 10.1038/s41559-018-0728-7 

Journal reference: Nature Ecology & Evolution 
Provided by: University of Bristol



Read more at: https://phys.org/news/2018-12-discovery-...s.html#jCp





Fossils suggest flowers originated  Arrow  50 million years earlier than thought  Doh

December 18, 2018, eLife

[Image: fossilssugge.jpg]
Nanjinganthus fossil, showing its ovary (bottom centre), sepals and petals (on the sides) and a tree-shaped top. Credit: Fu et al., 2018
Scientists have described a fossil plant species that suggests flowers bloomed in the Early Jurassic, more than 174 million years ago, according to new research in the open-access journal eLife.




Before now, angiosperms (flowering plants) were thought to have a history of no more than 130 million years. The discovery of the novel flower species, which the study authors named Nanjinganthus dendrostyla, throws widely accepted theories of plant evolution into question, by suggesting that they existed around 50 million years earlier. Nanjinganthus also has a variety of 'unexpected' characteristics according to almost all of these theories.

Angiosperms are an important member of the plant kingdom, and their origin has been the topic of long-standing debate among evolutionary biologists. Many previously thought angiosperms could be no more than 130 million years old. However, molecular clocks have indicated that they must be older than this. Until now, there has been no convincing fossil-based evidence to prove that they existed further back in time.

"Researchers were not certain where and how flowers came into existence because it seems that many flowers just popped up in the Cretaceous from nowhere," explains lead author Qiang Fu, Associate Research Professor at the Nanjing Institute of Geology and Paleontology, China. "Studying fossil flowers, especially those from earlier geologic periods, is the only reliable way to get an answer to these questions."

The team studied 264 specimens of 198 individual flowers preserved on 34 rock slabs from the South Xiangshan Formation—an outcrop of rocks in the Nanjing region of China renowned for bearing fossils from the Early Jurassic epoch. The abundance of fossil samples used in the study allowed the researchers to dissect some of them and study them with sophisticated microscopy, providing high-resolution pictures of the flowers from different angles and magnifications. They then used this detailed information about the shape and structure of the different fossil flowers to reconstruct the features of Nanjinganthus dendrostyla.

The key feature of an angiosperm is 'angio-ovuly' - the presence of fully enclosed ovules, which are precursors of seeds before pollination. In the current study, the reconstructed flower was found to have a cup-form receptacle and ovarian roof that together enclose the ovules/seeds. This was a crucial discovery, because the presence of this feature confirmed the flower's status as an angiosperm. Although there have been reports of angiosperms from the Middle-Late Jurassic epochs in northeastern China, there are structural features of Nanjinganthus that distinguish it from these other specimens and suggest that it is a new genus of angiosperms.

Having made this discovery, the team now wants to understand whether angiosperms are either monophyletic—which would mean Nanjinganthus represents a stem group giving rise to all later species—or polyphyletic, whereby Nanjinganthus represents an evolutionary dead end and has little to do with many later species.

"The origin of angiosperms has long been an academic 'headache' for many botanists," concludes senior author Xin Wang, Research Professor at the Nanjing Institute of Geology and Paleontology. "Our discovery has moved the botany field forward and will allow a better understanding of angiosperms, which in turn will enhance our ability to efficiently use and look after our planet's plant-based resources."

 Explore further: Ancient flower fossil points to core eudicot boom 99 million years ago

More information: Qiang Fu et al, An unexpected noncarpellate epigynous flower from the Jurassic of China, eLife (2018). DOI: 10.7554/eLife.38827 

Journal reference: eLife 
Provided by: eLife



Read more at: https://phys.org/news/2018-12-fossils-mi...t.html#jCp
Along the vines of the Vineyard.
With a forked tongue the snake singsss...
Reply
#32
We really are "re-defining" what we have in Scientific 'Group Think'.

As I stated in a note by your earlier quantum measurements, ALL things should be re-thought.

Even as we discover new things in science; we have human 'culture' moving BACKWARDS into Mason Zionists Satanist behavior.  You can now be fired for not having teaching students their true history of Palestine, ALL schools teachers in 29 different states must sign letter not to Boycott Israeli items or take any action promoting such, ALL new congress critters must also sign this pledge.

Even the Donald is in trouble with the Israelis and NOT the Russians for gaming the 2016 elections Mueller is moving in.

That's what my little bird told me. Cry

Bob... Ninja Assimilated
"The Light" - Jefferson Starship-Windows of Heaven Album
I'm an Earthling with a Martian Soul wanting to go Home.   
You have to turn your own lightbulb on. ©stevo25 & rhw007
Reply
#33
...couple molecules ago.
[Image: brainreprese.jpg]
Brain represents optical illusion as delayed reality
A study of humans and monkeys published in JNeurosci has found the same subset of neurons encode actual and illusory complex flow motion. This finding supports, at the level of single neurons, what the Czech scientist Jan ...
[Image: 1x1.gif]Feb 18, 2019 in Neuroscience

Quote:Posted by rhw007 - Wednesday, December 19th, 2018, 05:14 am
We really are "re-defining" what we have in Scientific 'Group Think'.

As I stated in a note by your earlier quantum measurements, ALL things should be re-thought.

and with that caveat.





[Image: darwinsfinch.jpg]
Darwin's finches don't tell the whole story of avian evolution
The connection between bird diet and skull shape is surprisingly weak for most species according to a new study led by UCL and the Natural History Museum, 
[Image: source.gif]
rewriting our understanding of how ecosystems influence evolution.
[Image: 1x1.gif]5 minutes ago in Evolution




Although it took 2 months to reply...as far as evolution is concerned ,itza blink of an eye. LilD
Quote:Posted by rhw007 - Wednesday, December 19th, 2018

Brain represents optical illusion as delayed reality
by Society for Neuroscience
[Image: brainreprese.jpg]
                               Fixate the black dot move backwards away from origin point.

                                                           Walking backward Improvising fore wordz.


Quote:"It is evolutionary history, rather than diet, that has most significantly influenced cranial shape. If you are descended from a duck-like ancestor,youareaduck you will probably have a duck bill, no matter what diet you have.  However, shared diet establishes the parameters of skull evolution, determining the range of potential shapes which can evolve," added Dr. Felice.



Darwin's finches don't tell the whole story of avian evolution

February 19, 2019, University College London



[Image: darwinsfinch.jpg]
This shows the very different skull shape in four different bird species that all eat the same diet: aquatic animals. Despite eating similar diets, they acquire their prey in very different ways and have very different skull shapes. The colored dots on each skull are the 3D landmarks used to quantify skull shape, and each color represents a different sub region of the skull. From top to bottom, the northern gannet (Morus bassanus), Eurasian spoonbill (Platalea leucorodia), the brown pelican (Pelecanus occidentalis), and the Adélie penguin (Pygoscelis adeliae). Credit: Dr. Ryan Felice, UCL



The connection between bird diet and skull shape is surprisingly weak for most species according to a new study led by UCL and the Natural History Museum, rewriting our understanding of how ecosystems influence evolution.








Charles Darwin's 19th century observations of finches on the Galápagos Islands concluded that bird speciation was primarily influenced by ecosystem; the way a bird forages and eats forms its skull shape and drives evolutionary change.



However, a new study by UCL and NHM researchers testing a wider range of species than ever before has found that on a global scale, shared ancestry and behaviour are more important factors than diet.



The study, published in Royal Society journal Proceedings B, tested the skull shape of 352 bird species, representing 159 out of the 195 existing families, making it the largest study of its kind.



"If we apply Darwin's conclusion for different kinds of birds who primarily eat fish, pelicans and penguins should have exactly the same head and beak shape, as they both use their beaks to eat fish. However, pelicans have a long beak and large throat pouch, while penguins' beaks are comparatively small," explained Dr. Ryan Felice (UCL Biosciences), one of the authors of the study.



"Although they eat the same thing, pelicans and penguins acquire their prey in different ways, demonstrating the important role behaviour plays in cranial evolution."



Penguins' mouths have a series of spines pointing down their throats, so that food stays in there when caught. Pelicans ingeniously catch fish in their pouch and then tip it back to drain out the water and swallow the fish immediately.



"It is evolutionary history, rather than diet, that has most significantly influenced cranial shape. If you are descended from a duck-like ancestor, you will probably have a duck bill, no matter what diet you have. However, shared diet establishes the parameters of skull evolution, determining the range of potential shapes which can evolve," added Dr. Felice.



The researchers also discovered that birds who eat grains—such as finches and quail—and those who survive on the nectar of flowers—like hummingbirds—exhibit the highest rate of cranial evolution. By contrast, terrestrial carnivores—hawks, falcons, owls and other birds who hunt and eat using their talons—exhibit a very slow rate of cranial change.



"This is where natural selection comes into play," said Professor Anjali Goswami, a Research Leader at the Natural History Museum and a co-author on the study.



"Birds that eat nectar or seeds are going to experience lots of competition for resources and must evolve in order to survive."



"Our study focused on the skull, but we hypothesise that other parts of the body could be shaped by diet and ecology, such as wings, talons, and stomachs, as these are the parts of their bodies which are crucial for catching and digesting prey."



The study used state-of-the-art equipment to build high resolution 3-D digital models of the bird skulls. This allowed researchers to plot many more points on the skull than previously possible, allowing them to make robust and accurate measurements.



"Our next step is to expand this analysis to other groups of animals, like mammals, reptiles, and dinosaurs," said Dr. Felice. "Our goal is to understand all of the different factors that have shaped skull evolution through time."



Dr. Felice's partners on the paper were Dr. Joseph Tobias (Imperial College London), Dr. Alex Pigot (UCL Biosciences) and Professor Anjali Goswami (UCL Biosciences & Natural History Museum).



Explore further: Bird beaks did not adapt to food types as previously thought, study suggests



More information: Dietary Niche and the Evolution of Cranial Morphology in Birds , Proceedings of the Royal Society B: Biological Sciences (2019). DOI: 10.1098/rspb.2018.2677 



Journal reference: Proceedings of the Royal Society B
Provided by: University College London





Read more at: https://phys.org/news/2019-02-darwin-finches-dont-story-avian.html#jCp
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