Links With Your Coffee
Thanks Shelley
I know. I was just as surprised as you are. Dr. Francis Collins, former director of the Human Genome Project, author of The Language Of God, and new director of the National Institutes of Health performed live in front of a group of Washington locals at the Capitol building today. He actually jammed with Aerosmith’s Joe Perry in an “unplugged” performance of Bob Dylan’s, “The Times They Are A Changin’.” This is not the kind of thing one expects in the hallowed halls of the Capitol building. But maybe it’s time to expect the unexpected?
PARIS (AFP) – The stunning remains of a "four-winged" dinosaur have confirmed that birds owe their ancestry to two-footed dinosaurs that lived millions of years ago, the world's most famous fossil-hunter said. Xing Xu of the Chinese Academy of Science in Beijing is staking the claim thanks to an astonishingly-preserved fossil of a bird-like dinosaur called Anchiornis huxleyi. Until now, A. huxleyi was thought to be a primitive bird. It was presumed to have been a near-contemporary of Archaeopteryx, the first recognised bird, which flew around 150 million years ago. But these opinions were based on an incomplete fossil. The new, nearly-complete specimen gives a different picture, suggesting that A. huxleyi is millions of years older than Archaeopteryx and has both dinosaur and avian features. It is the long-sought evidence that proves birds descended from theropod dinosaurs, argues Xu.
Lorrie Moore, the award-winning fiction writer, talks about her new novel, "A Gate at the Stairs," with Sam Tanenhaus, the editor of The New York Times Book Review.
Comments
A. huxleyi is a great example of how evolutionary hypotheses are totally subject to testing: look for more fossils and use the new fossils to do more refined analyses on the fossils we have. The hypothesis is: birds are descended from theropod dinosaurs. The null hypothesis is that they aren't. Evidence supporting the theropod link would be to find a fossil, older than Archaeopteryx, that has a mixture of bird and theropod characters (being relatively more theropod-like than Archaeopteryx). That's pretty much what A. huxleyi is. Creationists are always on about the lack of transitional forms in the fossil record. This is a canard; there are plenty. A huxleyi is just the latest good example.
The term "four winged" is a little weird. Yes, A. huxleyi had feathers on all four limbs, but it's joints show quite clearly (as the authors themselves state) that the thing couldn't have flown. Thus, the term 'wing' should really be avoided. The feathers very likely had a thermoregulatory function in these stem group birds (this is an old hypothesis). Eventually (i.e. later in bird evolution), these feathers took on a new function in flight, which, if true, would be a great example of what Gould famously called a spandrel.
Cool stuff.
Post a comment