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.
(But if you really WANTED a brown slug of plastic...)
I think it's interesting that a variant on that theory was roundly ridiculed...
by two characters in the book The French Lieutenant's Woman...
Cheers!
You should keep doing what you insist on doing. Refuse any knowledge. You should deny all facts and suppress science so everyone can return to the dark ages where all was faith and belief. I don't know the best for all education but I would accept new knowledge. The only accept you allow is your own opinion. It is possible though not likely that your worst nightmare may come true. Someday someone might observe ID or creation as a fact. As a observed fact, whether by a Deity, God, nature or otherwise it will be explained as a observed fact by science. It will become a thing known.
It will not affect science other than greater acceptance of science. However your philosophy and all others will be devastated. Philosophy may cease to exist. All religions vary and in the end only one or none can be correct. The knowledge of science that you refuse to accept will become the religion that you accuse it to be and will be accepted by most.
Maybe you can;t because you have no method. However of 6.7 billion people on earth most agree their are no two exactly the same. However a few deny change and think themselves clones.
Is that a trick question?
What was it that science observed? I didn't get it.
"I've yet to meet a human that lays eggs, much less hang from trees on its days off, unless you want to discuss the welfare class."
Anyone miss this bit o' racism from the Creationoid PistolPaknMama?
Who notices racism in America. Hell,that would be like being aware of the pull of gravity. (sarcasm aimed at the race baters and their liberal abetors, such as Alan Colmes)
Anyone miss this bit o' racism from the Creationoid PistolPaknMama?
Yeah but I haven't decided which is smarter. Those that lay around and are supported by those working or those working to support those laying around.
More like kittens now, but still a bit ratty.
"Looked" and "moved" seem to be the key words here, milord. There are real things — and there are simulacra of real things, if the experience/testimony of humankind in historical experience might be recognized as material to this dialog.
To suggest that the above statement is in any way aligned with a truthful analytical standard according to which we humans ought to be moving right now, in response to the exigencies of current global realities, strikes me as a bit tendentious. In that it assumes as true (valid) the very thing that remains to be tested, falsified, or "proved." I.e., that simulacra have free will, such that they can, for example, willingly flee a battlefield.
Though it is interesting that cyborgs in this fictional piece reacted the way they did, we have no way of reliably ascertaining, of knowing, why they did so. Are cyborgs "reasonable," strictly speaking?
Somehow I think that C. S. Lewis would have had a field day with the sort of reasoning presented in the article at the top of this thread....
Oh. I just noticed our little conversation has been removed to the "Smokey Backroom".... How delightful! Thanks so much for writing, King Prout! Good night!
on post 1082, I forgot to include the assumption of not being aware of the ToE.
So, if we weren't aware of that theory, and came across this, and other fossils, would we develop it or something else to explain the fossils.
Are we making evidence fit the theory?
...based on reason alone.
Scientific empiricism does not guarantee "truth" (whatever that is), but it is the most effective method known for minimizing and discovering errors. Things which have not been scientifically verified may happen to be correct, but the *level* and *type* of certainty are different.
Anyone who says they are certain is simply emoting.
Not necessarily emoting. There are degrees of trust and confidence (say in the expertise of a pilot or a wine-taster) which, while not as justified as scientific rigor, are not due merely to emotion or chance.
Thank God.. A cigar and an adult beverage would be nice about now..
And I agree with you that self-induced blindness is the worst kind.
Thank you for your reply, dear hosepipe!
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