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.
BUAHAHAHAHAHHA!
You DON'T know what an argument is!! LOLOLOLOL! I didn't think you would actually post your ignorance.
Hint: An argument is unilateral ;)
I don't mind posting my ignorance. Look at some of my posts and you'll see!
The method of putting the two boards lies in truth.
nailing them together = Yes
Glueing them = Yes
Nailing and glueing = Yes
Dove tail = Yes
Pins/dowels = Yes
Using rubber bands = No
Your point is that you choose to believe that truth is only relative to your belief. When infact people believed the earth was once flat, which is not true. therefore what people believe doesn't constitute truth.
Actually, there are now two new gaps.
Show me the arguments. Science has only said that Creation and ID cannot be explained by science because they have not been observed as a material fact. If either can observe life different present the material fact and evidence.
Hypocrite!
Who is more qualified on the subject of life more than God?
Well, unadulterated inorance undermines your position.
Do a little research -- it is easy on the web.
FYI: An argument is a series of (logically provable) statements that support a proposition.
Thanks. I appreciate your help. It isn't easy being an illiterate Freeper!
It is until it starts making statements to the exclusion of, or against intelligent design. When faced with the idea that organized matter performing specific functions MIGHT be best explained by intelligent design, evolutionists cannot shut their mouths, even though they have nothing better to offer. Whatever they decide to offer as a better explanation, if ever such a thing should happen, it will not be science either.
And to the extent they posit scenarios that involve unobserved, undocumented events, they also depart from empirical science and step into the void of reasonable conjecture based upon their own a priori assumptions, such as uniformitarianism.
Creation is all around us - how can you say it isn't observed?
What creation have you observed as a material fact.
Define "material fact".
NIV Isaiah 59:15
Truth is nowhere to be found, and whoever shuns evil becomes a prey. The LORD looked and was displeased that there was no justice.
Between me and you, it isn't possible. ;)
"#826"
No, I got the point. You believe whatever one wishes to be reality can be.
"Sometimes "black" is "white""
And war is peace. More doublespeak.
"However, in terms of things spiritual, concepts such as "objective reality" don't have meaning."
True. But Christians don't believe that the Bible deals only in things *spiritual*. They believe it deals with objective reality too, something you deny exists.
Workin' in a quote mine
Goin' down down down
Workin' in a quote mine
Whop! about to slip down
Workin' in a quote mine
Goin' down down down
Workin' in a quote mine
Whop! about to slip down
Five o'clock in the mornin'
I'm all ready up and gone
Lord I am so tired
How long can this go on?
Your level of personal moral depravity has no bottom, does it?
A material fact is a phenomena that can be observed by the senses and there is evidence and emperical evidence for the fact. The method of science is obsevation of a material fact, evidence and emperical evidence of the fact and a explination of the fact that constitutes theory. The method does not observe anything other than a material fact. Without a material fact there can be no scientific theory. Facts are not absolute and a theory is of a higher order than a fact.
A material fact is a phenomena that can be observed by the senses and there is evidence and emperical evidence for the fact. The method of science is obsevation of a material fact, evidence and emperical evidence of the fact and a explination of the fact that constitutes theory. The method does not observe anything other than a material fact. Without a material fact there can be no scientific theory. Facts are not absolute and a theory is of a higher order than a fact.
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