were separated at birth!
Cheers!
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.
Oh good gawd. Go back to your post 426 which was a response to my post 424. I didn't mention either sharks or marsupials in my post. You brought up sharks and I had no idea why you did. Maybe you meant to reply to someone else. I don't have to explain why sharks were wandering around with marsupials. You said "Early placental mammals were driven from Australia by marsupials due to their reproductive superiority." I have no idea why you brought this up. I have no idea about sharks or marsupials except that it seems they would not compete for the same resources.
We simply cannot revise what Darwin understood as "evolution" to mere change.
Again
Darwin said this almost 150 years ago.
This is from Origin of Species (6th ed.), Chapter 2 - Variation Under Nature:
The many slight differences which appear in the offspring from the same parents, or which it may be presumed have thus arisen, from being observed in the individuals of the same species inhabiting the same confined locality, may be called individual differences. No one supposes that all the individuals of the same species are cast in the same actual mould. These individual differences are of the highest importance for us, for they are often inherited, as must be familiar to every one; and they thus afford materials for natural selection to act on and accumulate, in the same manner as man accumulates in any given direction individual differences in his domesticated productions.
There are also snakes that give live birth.
Leaving your eggs lying about is risky.
However, the second statement about Australia, South America and Antarctica was separate and distinct from anything having to do with sharks.
Your response to that suggested that you thought it to be a long swim from Australia (with its marsupials) to anywhere else (with marsupials).
Great Debate among evolutionists, creationists and intelligent designers.
The only place this debate is Great is in the minds of the creationists and intelligent designers. There is no debate among 99+% of scientists. And there is no debate between creationists/intelligent designers and that 99+% of scientists. The creationists/intelligent designers are just trying to create the illusion there's a debate, in the minds of an uninformed public, for political purposes, to advance their religious beliefs. And that is the Dove PA case in a nutshell.
"But it's still a fis... er, creeping th... - whatever it is, it's still one of those - no evolution there."
They also had strange views about sheep.
I don't know. Its not a subject I have considerd or have other than general knowledge.
Thanks for proving my earlier point and not wasting any more of my time. Evolution does not equal intelligent life form. Now I understand, thanks!
I didn't respond to anything about marsupials except how the marsupials would compete with sharks and run them into the sea. I think you just responded to the wrong posts. :-)
No you're a monkey's nth cousin
"Thanks for proving my earlier point and not wasting any more of my time."
Your silly statements still stand. No evolutionists say that there ever were egg laying primates. Nor is there any reason at all to think there should have been egg laying primates.
You didn't explain your *gills to testicle* theory. Does that require a few more pints?
"Evolution does not equal intelligent life form. Now I understand, thanks!"
In that case you may have evolved after all.
You are correct about one thing; these debates are over your head. Here is a link for something a little easier for you:
http://knitting.about.com/
J. Craig Venter has proposed creating an artificial lifeform into which we would insert genes found in viruses in the oceans (by the tens, if not hundreds, of millions, to see what they do).
Now that's "noncommital".
There are many people outside the three realms who'd just like to see how the whole machine works ~ and forget about this common origin stuff ~ it's gumming everything up and blinding us to the possibilities of real research.
Possibly a poor choice of words, there, PH. If you meant "produce" as in "to present" or "to display", yes.
But I shudder to think of some of the more zealous adherents of ID attempting to concoct such a fossil and pass it off as legitimate, using the justification "well, look at the platypus, it doesn't make sense either."
Full Disclosure: Harpies don't count. We already have mentions of Helen Thomas photos in the first few replies...
Cheers!
Have a good night.
were separated at birth!
Cheers!
Whatever his time, he observed a fact not noticed by others thousands of years before. 400 religious views today are different and some have strange views of sheep.
Cheers!
Big difference.
Folks had been watching "facts" for hundreds of years when they flew kites. The Wright Brothers, however, came up with an idea, and proved it with a working model.
Di: Evidence exists for viral insertion of genetic information. What evidence do you have for "recombinant DNA technology" as a mechanism for the aquisition of genetic information? Be sure to specify the mechanisms of the technology itself.
Just to stir the pot, check out this site.
Full Disclosure: H5N1. Tag, you're it.
Cheers!
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