|
|
|
| GGG managers are SunkenCiv, StayAt HomeMother & Ernest_at_the_Beach | |
|
|
Thanks Red Badger. |
|
|
|
|
Posted on 07/27/2011 1:55:41 PM PDT by Red Badger
One of the world's most famous fossil creatures, widely considered the earliest known bird, is getting a rude present on the 150th birthday of its discovery: A new analysis suggests it isn't a bird at all.
Chinese scientists are proposing a change to the evolutionary family tree that boots Archaeopteryx off the "bird" branch and onto a closely related branch of birdlike dinosaurs.
Archaeopteryx (ahr-kee-AHP'-teh-rihx) was a crow-sized creature that lived about 150 million years ago. It had wings and feathers, but also quite un-birdlike traits like teeth and a bony tail. Discovered in 1861 in Germany, two years after Charles Darwin published "On the Origin of Species," it quickly became an icon for evolution and has remained popular since.
The Chinese scientists acknowledge they have only weak evidence to support their proposal, which hinges on including a newly recognized dinosaur.
Other experts say the change could easily be reversed by further discoveries. And while it might shake scientific understanding within the bird lineage, they said, it doesn't make much difference for some other evolutionary questions.
Archaeopteryx dwells in a section of the family tree that's been reshuffled repeatedly over the past 15 or 20 years and still remains murky. It contains the small, two-legged dinosaurs that took the first steps toward flight. Fossil discoveries have blurred the distinction between dinosaurlike birds and birdlike dinosaurs, with traits such as feathers and wishbones no longer seen as reliable guides.
"Birds have been so embedded within this group of small dinosaurs ... it's very difficult to tell who is who," said Lawrence Witmer of Ohio University, who studies early bird evolution but didn't participate in the new study.
The proposed reclassification of Archaeopteryx wouldn't change the idea that birds arose from this part of the tree, he said, but it could make scientists reevaluate what they think about evolution within the bird lineage itself.
"Much of what we've known about the early evolution of birds has in a sense been filtered through Archaeopteryx," Witmer said. "Archaeopteryx has been the touchstone... (Now) the centerpiece for many of those hypotheses may or may not be part of that lineage."
The new analysis is presented in Thursday's issue of the journal Nature by Xing Xu of the Chinese Academy of Sciences in Beijing, and colleagues. They compared 384 specific anatomical traits of 89 species to figure out how the animals were related. The result was a tree that grouped Archaeopteryx with deinonychosaurs, two-legged meat-eaters that are evolutionary cousins to birds.
But that result appeared only when the analysis included a previously unknown dinosaur that's similar to Archaeopteryx, which the researchers dubbed Xiaotingia zhengi. It was about the size of a chicken when it lived some 160 million years ago in the Liaoning province of China, home to many feathered dinosaurs and early birds.
Julia Clarke of the University of Texas at Austin, who did not participate in the study, said the reclassification appeared to be justified by the current data. But she emphasized the study dealt with a poorly understood section of the evolutionary tree, and that more fossil discoveries could very well shift Archaeopteryx back to the "bird" branch.
Anyway, moving it "a couple of branches" isn't a huge change, and whether it's considered a bird or not is mostly a semantic issue that doesn't greatly affect larger questions about the origin of flight, she said.
Luis Chiappe, an expert in early bird evolution at the Natural History Museum of Los Angeles County who wasn't part of the new study, said he doesn't think the evidence is very solid.
"I feel this needs to be reassessed by other people, and I'm sure it will be," he said.
To say birds evolved from a ground bound species like raptors is BS, especially when there were many air borne species already flying around. Why wouldn't the flying lizards have been the ones to evolve into birds? The fact is, there is zero evidence to support the dino to bird theory except for speculation on the parts of evolutionists.
Like the story of the blind men and the elephant.......
If it looks like a duck.....
Heck, the next thing you know scientists will figure out that petroleum doesn’t come from “fossils” 5000 feet under hard granite.....
Many of the so called “dino bird” fossils recently found in China, in fact all, have been outed as fakes and the so called feathers were not feathers at all.
?????
People who refute evolution are as unconvinceable as atheists. Atheists wouldn’t believe in Christ if he turned water into wine right under their noses, and anti-evolutionists try to explain away the preponderant weight of scientific evidence which sustains evolution, with convoluted, distorted arguments which are more unbelievable than the theory they attempt to disprove.
The Archeopteryx has definite intermediate characteristics - wings, feathers, teeth, claws. The presumable dinosaurs which gave rise to birds had wishbones, hollows in their bones, the same foot structure, and in some cases, feathers.
“Why wouldn’t the flying lizards have been the ones to evolve into birds? “
They do have as close a skeletal similarity to birds as do Raptor like dinosaurs. Their flight was more similar to that of bats than of birds.
Many of the so called “dino bird” fossils recently found in China, in fact all, have been outed as fakes and the so called feathers were not feathers at all.
?????
People who refute evolution are as unconvinceable as atheists. Atheists wouldn’t believe in Christ if he turned water into wine right under their noses, and anti-evolutionists try to explain away the preponderant weight of scientific evidence which sustains evolution, with convoluted, distorted arguments which are more unbelievable than the theory they attempt to disprove.
The Archeopteryx has definite intermediate characteristics - wings, feathers, teeth, claws. The presumable dinosaurs which gave rise to birds had wishbones, hollows in their bones, the same foot structure, and in some cases, feathers.
“Why wouldn’t the flying lizards have been the ones to evolve into birds? “
They do have as close a skeletal similarity to birds as do Raptor like dinosaurs. Their flight was more similar to that of bats than of birds.
Also, Archeopteryx is much older than these supposed therapod dino-bird missing links that are featured on, say, Discovery channel.
|
|
|
| GGG managers are SunkenCiv, StayAt HomeMother & Ernest_at_the_Beach | |
|
|
|
Thanks Red Badger. |
|
|
|
|
Actually the Chinese fake birds were in the news a couple of times in the 90s, also some fake dinosaur re-assemblys. Folks wanted to make a little money.
Interesting post. I have wondered why anyone would think that a creature with scales would, through natural selection, grow feathers. Until it was completely feathered and able to fly, there seems no benefit and a pretty significant liability to having a few feathers versus having a lot of scales. Add to that the transition from cold blooded to warm blooded... well, again, it is hard to see that happening incrementally as there is no survival advantage until the transition is complete.
R-ky-op-tur-icks
The first reason for feathers, before flight was even possible, would be body temperature control for small creatures.
Feathers are insullation, keeping small animals warmer in the cold and cooler in warm times.
If those feathered animals now leap from one tree to another, or off a high bank, certain types of feathers might help extend the leap, or slow the fall...
Get it?
TN4Liberty: "Add to that the transition from cold blooded to warm blooded... well, again, it is hard to see that happening incrementally as there is no survival advantage until the transition is complete."
"Hard to see..."??
Of course it's hard to see, if you refuse to open your eyes, pal.
Today, the very words cold blooded and warm blooded are falling into disuse, precisely because there are so many intermediate living animals which have some characteristics of both.
Among generally colder-blooded animals, tuna, swordfish and sharks have some warm-blooded characteristics.
Among generally warmer-blooded animals, bats and some small birds have have colder-blooded characteristics.
In short, even today there are advantages to intermediate forms.
Why is that so "hard to see..."?
In plain fact, no scientist can explain how these evolutionary leaps occured. And then there is the enigma of how complex life arose spontaneously from carbon chains in the seas. If they stuck to just the well established facts, evolutionists would have to admit they have no adequate theory to explain either life's origins or the flowering of so many species.
Certainly this is a possibility. But then someone needs to explain why my cat doesn't have feathers. In fact, I am aware of no small mammal which sports featers rather than fur.
As I stated above, I am not anti-evolution (ie. I am not a 'created by God in 7 days' person). But I believe evolution has been intelligently guided, either directly by God or indirectly by some sort of feedback mechanism whereby the built-in intelligence of Nature is able to assess data from the environment and design evolutionary changes accordingly. I do not believe in a Nature-as-God concept such as Gaia. I believe in the Holy Father of Jesus.
If the above is not perfectly clear it's because evolutionary science is primarily still in the theoretical stage. I don't have the answers to the vital questions, but I can recognize dissembling on the part of advocates of mechanistic evolution when I encounter it.
Of course they can.
You just don't like the explanations, because they don't fit your religious ideas.
Evolution facts include the confirmed observations of A) descent with modifications and B) natural selection.
Evolution theory is many-times confirmed in the fossil record, in DNA analyses and inputs from virtually every other branch of science.
And there is no other scientific theory to compete with Evolution.
Indeed, there is not even a serious alternate scientific hypothesis out there.
Yes, the origin of life on earth is the subject of several scientific hypotheses, most of them various possible types of abiogenesis.
Another two potential hypotheses have been mentioned, though neither is testable scientifically: panspermia (life arrived on meteors from outer space) and intelligent design (which is unspecified in scientific terms).
ARepublicanForAllReasons: "If they stuck to just the well established facts, evolutionists would have to admit they have no adequate theory to explain either life's origins or the flowering of so many species."
Evolution theory does not explain life's origins.
Evolution theory begins once life has started.
Several hypotheses for abiogenesis have been proposed, though none has yet been confirmed.
The "flowering of so many species" is a simple extension over time of basic evoloutionary processes: A) descent with modifications and B) natural selection.
Bird down feathers have enough similarities to mammal hair to suggest they evolved to serve the same purposes.
Consider:
These facts suggest that mammal hair likely evolved many mullions of years before the earliest bird feathers.
But there is no reason I know of to expect any connection will be found between the earliest mammal hair and later bird down feathers.
ARepublicanForAllReasons: "I don't have the answers to the vital questions, but I can recognize dissembling on the part of advocates of mechanistic evolution when I encounter it."
I shudder to think whom you might have "encountered".
Did you not have a good science teacher in any grade in school?
Basic science consists of facts (=confirmed observations), hypotheses (unconfirmed explanations) and theories (confirmed explanations), plus an occasional scientific "law" which can be expressed mathematically.
Regarding evolution, there are facts, a confirmed theory and a number of unconfirmed hypotheses.
There are no mathematical "laws" of evolution, that I know of.
So, my point is: what, exactly is your problem with the scientific facts, theory and hypotheses relating to evolution?
So you feel the need to be insulting why?
Quote the alleged insult, and explain your problem with it.
More important, explain why you can't see what should be perfectly obvious.
“TN4Liberty: “So you feel the need to be insulting why?”
Quote the alleged insult, and explain your problem with it.
More important, explain why you can’t see what should be perfectly obvious. “
Confrontational? Condescending? Better words? I would think that only a social misfit wouldn’t see that in your words. One must assume you were either deliberately insulting or socially tone deaf to explain your remarks. I’ll accept a third hypothesis if you can present one.
BTW, doing a little research - the feather from scale conversion is just one of many theories, all speculative, and all with holes in them. None are apparently universally accepted. Some speculation exists that perhaps scales evolved from feathers. Or perhaps both evolved from a common cell type that birds now have on their legs. Interesting concepts, don’t you think? One might wonder why you can’t see alternatives that are so obvious.
Also, I’d appreciate some links describing cold blooded birds and warm blooded reptiles you speak of (or semi-cold/semi-warm). Thanks in advance.
Ah, you did provide links. Wikipedia. I’ll get right on that. Meanwhile, you can go back to insulting everyone on the thread.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.