Posted on 04/05/2006 10:32:31 AM PDT by PatrickHenry
Paleontologists have discovered fossils of a species that provides the missing evolutionary link between fish and the first animals that walked out of water onto land about 375 million years ago. The newly found species, Tiktaalik roseae, has a skull, a neck, ribs and parts of the limbs that are similar to four-legged animals known as tetrapods, as well as fish-like features such as a primitive jaw, fins and scales.
These fossils, found on Ellesmere Island in Arctic Canada, are the most compelling examples yet of an animal that was at the cusp of the fish-tetrapod transition. The new find is described in two related research articles highlighted on the cover of the April 6, 2006, issue of Nature.
"Tiktaalik blurs the boundary between fish and land-living animal both in terms of its anatomy and its way of life," said Neil Shubin, professor and chairman of organismal biology at the University of Chicago and co-leader of the project.
Tiktaalik was a predator with sharp teeth, a crocodile-like head and a flattened body. The well-preserved skeletal material from several specimens, ranging from 4 to 9 feet long, enabled the researchers to study the mosaic pattern of evolutionary change in different parts of the skeleton as fish evolved into land animals.
The high quality of the fossils also allowed the team to examine the joint surfaces on many of the fin bones, concluding that the shoulder, elbow and wrist joints were capable of supporting the body-like limbed animals.
"Human comprehension of the history of life on Earth is taking a major leap forward," said H. Richard Lane, director of sedimentary geology and paleobiology at the National Science Foundation. "These exciting discoveries are providing fossil 'Rosetta Stones' for a deeper understanding of this evolutionary milestone--fish to land-roaming tetrapods."
One of the most important aspects of this discovery is the illumination of the fin-to-limb transition. In a second paper in the journal, the scientists describe in depth how the pectoral fin of the fish serves as the origin of the tetrapod limb.
Embedded in the fin of Tiktaalik are bones that compare to the upper arm, forearm and primitive parts of the hand of land-living animals.
"Most of the major joints of the fin are functional in this fish," Shubin said. "The shoulder, elbow and even parts of the wrist are already there and working in ways similar to the earliest land-living animals."
At the time that Tiktaalik lived, what is now the Canadian Arctic region was part of a landmass that straddled the equator. It had a subtropical climate, much like the Amazon basin today. The species lived in the small streams of this delta system. According to Shubin, the ecological setting in which these animals evolved provided an environment conducive to the transition to life on land.
"We knew that the rocks on Ellesmere Island offered a glimpse into the right time period and the right ancient environments to provide the potential for finding fossils documenting this important evolutionary transition," said Ted Daeschler of the Academy of Natural Sciences in Philadelphia, a co-leader of the project. "Finding the fossils within this remote, rugged terrain, however, required a lot of time and effort."
The nature of the deposits where the fossils were found and the skeletal structure of Tiktaalik suggests the animal lived in shallow water and perhaps even out of the water for short periods.
"The skeleton of Tiktaalik indicates that it could support its body under the force of gravity whether in very shallow water or on land," said Farish Jenkins, professor of organismic and evolutionary biology at Harvard University and co-author of the papers. "This represents a critical early phase in the evolution of all limbed animals, including humans--albeit a very ancient step."
The new fossils were collected during four summers of exploration in Canada's Nunavut Territory, 600 miles from the North Pole, by paleontologists from the Academy of Natural Sciences in Philadelphia, the University of Chicago and Harvard University. Although the team has amassed a diverse assemblage of fossil fish, Shubin said, the discovery of these transitional fossils in 2004 was a vindication of their persistence.
The scientists asked the Nunavut people to propose a formal scientific name for the new species. The Elders Council of Nunavut, the Inuit Qaujimajatuqangit, suggested "Tiktaalik" (tic-TAH-lick)--the word in the Inuktikuk language for "a large, shallow water fish."
The scientists worked through the Department of Culture, Language, Elders and Youth in Nunavut to collaborate with the local Inuit communities. All fossils are the property of the people of Nunavut and will be returned to Canada after they are studied.
The team depended on the maps of the Geological Survey of Canada. The researchers received permits from the Department of Culture, Language, Elders and Youth of the Government of Nunavut, and logistical support in the form of helicopters and bush planes from Polar Continental Shelf Project of Natural Resources Canada. The National Science Foundation and the National Geographic Society, along with an anonymous donor, also helped fund the project.
"Must make you proud inventing such an ignorant strawman argument. Do you have anything of substance to say about THIS find, or are you content to just make things up?"
To be sure, that was not a bad satire of the often ridiculous extrapolations made on popular "science" shows like "When Dinosaurs Roamed" (or whatever it was called). I mean, with a few exception, they don't know how these critters moved and certainly can't tell us much about how they behaved, but those programs make out as if we know as much about their behaviour and life cycle as we do African lions, for example. I wouldn't mind it too much if they would preface the show (and every return from a commercial) with a disclaimer that nearly everything you are about to see is highly (extremely highly) speculatory.
Now you're just lying.
Saying doesn't make it so. Do you have a specific objection or are you just in the mood to be contrary?
I dunno... maybe some do like that idea...
The analogy to red shift is also not sound scientifically, but as a lay explanation is fine. Don't ever confuse the two and forget DNA in living organisms propigated by reproduction over time is not the same as particles of light travelling in space.
Here is a better tree of life project.
Also, I am not sure if the text accompanying the post (10) is yours or from the project page in Arizona. eg, "Creationists are forever claiming that the evolutionary picture revealed by the evidentiary jigsaw puzzle is nothing more than the arbitrary result of our prejudices..."
Is this your writing or is it taken from the Arizona ToL project?
Thanks.
Did you write all that yourself?
no, the upsidedown darwin walking fish is a symbol of the theory of evolution is over...
Dinosaur science is a term that refers to older, less useful and informative methods being used. If you were a scientist you'd know that.
Mine. If I quote something, I always say so and give the source.
What a stupid remark. So if we find a fossil in the 21st century, it's 19th century research?
So, someone has actually observed something rise from nothing, observed life rise from non-life, observed multi-celled organisms rise from single-celled organisms, observed intelligence rise from non-intelligence? You've got yourself a scoop there, buddy.
No, most people have observed it including yourself. Evolution is defined simply as occurring change or change is ongoing or a observed fact. The Theory of Evolution explains the observed fact. For the simplest proof there are 6.7 billion people on earth and no two have been found to be exactly the same so some change has occurred. Get a picture of your parents and stand in front of a mirror. If you are exactly the same no change has occurred and you are a clone. However is if there is any difference, no matter how small, some change or evolution has occurred. Evolution whether by reproduction or nature is still change.
No one has observed something rise from nothing, observed life rise from non-life, observed multi-celled organisms rise from single-celled organisms, observed intelligence rise from non-intelligence, nor has science proclaimed to do so. It does not address things other than observed facts. That you would pretend that it does is dishonest and misinterpetation. The origin of life is your faith and belief and when you can present it as a material fact it will be explained by science.
Now if you have looked in that mirror, you may find that you are a clone in thought but you have changed as a material fact.
There's nothing "desparate [sic]" about reporting yet another find (out of countless thousands) which yet again match the predictions of evolutionary theory and thereby confirming evolution, while violating the predictions of the anti-evolutionists and thereby falsifying the beliefs of the anti-evolutionists. It happens on a daily basis.
What is "desparate [sic]" however, is the frantic hand-waving, frightened ridicule, rash straw men, urgent dismissals, and reckless insults employed by the anti-evolutionists in a frenzied attempt to try to convince anyone that these kinds of finds aren't actually the overwhelming confirmation of evolution that they obviously are.
If you're still unclear on the concept, read this: Explaining the Scientific Method.
"Actually, looking at the bones can give an excellent understanding of how they moved."
Up to a point. When I was child all the museums and books protrayed T.Rex and his close relatives as Godzilla-type creatures, standing up, quite improbably on their hind legs. Now they are pictured as carrying themselves much more like birds, with tail out behind and neck and head forward.
"Sure; but they don't, contrary to anti-evo belief, just make it up out of thin air."
They extrapolate so far from so little that they might almost as well. But of course those shows are not science, they're entertainment.
In your dreams. Meanwhile, the vast and overwhelming mountains of evidence and research findings confirming evolutionary biology, along multiple independent cross-confirming lines, continues to mount higher on a daily basis.
Are you sure you know what in the hell you're talking about?
Nonsense. Good science is good science and bad science is bad science, regardless of era.
Maxwell's Equations are still in use today. We still produce Sodium by the same basic method that Davy pioneered in 1807.
Thats trollhappy for ya.
I am going to go out on a limb and make a few bold predictions:
In his next few posts he will insult your knowledge and credentials. Then he will post pages of irrelevant information from random sources. Finally at the end of everything (after he takes his meds?) he'll say it was all a joke and you should lighten up.
I saw nothing in Strategerist's posting that suggests that he (or she, as the case may be) is "hoping" for anything. Why do you ask such a question?
...because that's the way Zavien Doombringer reaches *his* conclusions, and thus he (incorrectly) presumes that everyone else does likewise.
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