Revelation 4:11Intelligent Design
Constantly searching for objectivity in the evolution debate...
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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.
The two sources I linked are: (1) EurekAlert!, which is the online news service of The American Association for the Advancement of Science; and (2) Nature magazine, one of the most highly regarded, peer-reviewed science journals in existence. Not classy enough for you?
I have made mistakes on occasion, but this isn't one of them. As others have pointed out, Newton's Laws have been superceded by Einstein's theory of gravity, and work is in progress on a better theory of gravity.
Einstein's theory is more precise than Newton's Law.
No, it was probably the same idiots who wrote this:
Huge predators would have lurked in Tiktaalik's rivers and lakes, study co-leader Shubin says—perhaps one reason why Tiktaalik appears to have been headed for land.
"Land had no predators, and it also had food in the form of invertebrates," Shubin said. "Put this all together and the shallows and mudflats might have been a good place to make a living."
Supposedly learned individuals put out this drivel and then other supposedly learned individuals soak it up like sponges...
You get your science education from Hollywood movies?
"A" link, but not "the" link -- a chain has many links, and so does an evolutionary sequence.
Do you have any arguments of substance, or is the whole of your objection an appeal to ridicule, without any actual attempt to dispute the claims?
And here comes RightWingNilla on the inside. He's three lengths ahead of Intelligent Design, coming to the turn. Four lengths. Five lengths. In the final stretch...
It's not drivel, it's based on the actual evidence, unlike your desperate attempts at empty ridicule as a substitute for actual analysis.
and then other supposedly learned individuals soak it up like sponges...
Because it best fits the totality of the evidence and makes predictions which are subsequently validated. That's that "science" thing you must have heard about.
It's amazing. Scientists, using ToE, predict that a fossil like this must exist. Then, BAM, it turns up. Creationist logic? ToE is "over".
Thank you. It was not clear in the manner you presented it.
I would be very surprised to hear such diatribe from a respectable project such as the ToL project at Arizona.
Give a creationist a fish and he'll say you made it up.
You should be aware that ID, with its vastly superior explanatory model, anticipated this find. In fact it anticipates everything.
And that leaves dumbass clueless twits nothing to do but rant against it on FR?
Here's a free clue. They are learned. They stayed in school, and read books and stuff. They learned biology from books and biologists, not preachers. They know stuff you don't. All you have is an opinion, and you know what opinions are like.
Of course, all of the 'true believers' hang on every word.
Please identify what is incorrect in what he wrote. Be specific.
I ain't no monkey's uncle.
There are a number of fish lineages which have both gills and lungs (as do amphbians, at least at some stages of their life cycle), so the transition from fish to land-dweller isn't as strange or "difficult" as it might seem at first glance. Start with gills, at some point add an auxilliary air-storage bag (such as the swim bladder), the bag develops in stages over time into a more fully functional lung, then as the lineage spends more and more time on land, the gills become a useless vestage and fade away as the lungs become the exclusive oxygen-gathering system. Various stages of this transition can be found in numerous extant species.
Some of us both (a) accept the overwhelming evidence for the common descent of all life on earth, and also (b) believe that humanity was created in the (spiritual) image of God.
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