Show me LIVING creatures; I can draw THAT line really well.
If we dig up one of THESE, will it be ape, human, mutant, alien?
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.
then every once in a while, someone comes along, who actually asks probing questions, appears to hold one opinion, but does take the time to examine the evidence, and then admits that perhaps they were mistaken in their original analysis, and come around to seeing things in a different light...but that is really quite rare...
And then there are the posers. But you're point is well taken and the reason why it's best to be civil with the newly arrived on Crevo threads, except when they've registered in the past few months and start repeating the same old, same old stuff. You are a touchstone of civility and I thank you for that.
Well, I am not always civil...dont you remember my great faux pas on these threads? Altho, I did immediately apologize, and ask for my post to be removed...it was the one and only time I ever hit 'abuse', and it was 'abuse' called on myself...gosh I was so embarrassed...I thank you however for the compliment, I try to remain civil, sometimes tho, I just burst...
Good catch!
Actually, borders are ok as long as they are the same color! (Same on both sides...)
As soon as you nail the jello to the wall, along comes someone to eat it!
Ah, now I can type quite speedily..perhaps that is my problem...I need to slow down...perhaps that will save me from further faux pas in the future...type slow...type slow...thanks, this may work...
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. Using your creationist scientific postulates, where do you think the insurmountable barrier lies in #946?
Do I get to use Science or just look at the purty pictures?
Simple fix:
Hook up a generator to your treadmill to get the POWER for your PC!
You do consider yourself a creationist, don't you? It should be obvious then where the line should be drawn.. Using your creationist scientific postulates, where do you think the insurmountable barrier lies in #946?
Do I get to use Science or just look at the purty pictures?
Sorry double click. Maybe the mod can remove one.
Show me LIVING creatures; I can draw THAT line really well.
Math is even worse: group, ring, field, prime, associate, composite, unit, ideal, product, power, real, imaginary, fiber and on and on all have completely different meanings, which often have nothing in common with their ordinary meaning.
"ideal class group" sounds vaguely Marxist...
Every field of study has its own jargon, which simply has to be learned. Sometimes, as in the math examples, these are regular words. sometimes, like medicine or cladistics, they're made up for the occasion.
Gauss even borrowed Linnean taxonomic terms for the theory of quadratic forms: class, order, genus
"Golf has it's own dictionary too. Fat means something completely different than what it does in everyday life. If you want to converse in (and criticize) the domain you need to learn the lingo."
Good try, but I would change lingo to spin. :)
"What about the word 'love' in Tennis?...it means one thing in tennis, another thing applied to emotions..."
That's good; it reminds me of a hononym.
But I gotta say, does that mean that if the pro-ID people got THEIR own dictionary, would that make it correct, or does this separate dictionary only apply for the evo THEORY?
... Which is the opposite of a "hoyesnym"?
But I gotta say, does that mean that if the pro-ID people got THEIR own dictionary, would that make it correct, or does this separate dictionary only apply for the evo THEORY?
The pro-ID people are presently engaged in attempting to change the definition of science in an effort to claim ID is scientific. This in and of itself should be a convincing demonstration that ID isn't science.
We're not going to have to explain again why there's nothing wrong with a theory (or "THEORY" as you put it), again, are we? You know, as in "germ THEORY," "gravitational THEORY," "atomic THEORY"?
If you haven't yet grasped that each discipline has its own specialized vocabulary, or find that suspicious, you should consider continuing your education. Otherwise you might go around expecting to be able to taste quarks because they are classified into flavors.
Dear Sun: Beware evos who demand to set the terms, for they will control the debate if you allow them. And control is all these Asberger's sufferers (see wikipedia if you are unfamiliar with Asberger's Syndrome) are after. It's not like they'll have a date this Saturday night.
Dear Coyoteman--came across a nice little quote, and I thought of you--
Anthropologists believe that the plural of anecdote is “data.”
IOW--Anthropology is just sociology with relics. A social science trying to pass itself off as important.
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