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Newly found species fills evolutionary gap between fish and land animals
EurekAlert (AAAS) ^ | 05 April 2006 | Staff

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.


TOPICS: Heated Discussion
KEYWORDS: 375millionyears; coelacanth; crevolist; lungfish; tiktaalik; transitional
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To: Fester Chugabrew; CarolinaGuitarman
Intelligent design assumes

Assumption is a term of philosophy. Science assumes nothing and observes fact. The two methods are not compatible.

981 posted on 04/06/2006 3:56:32 PM PDT by jec41 (Screaming Eagle)
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To: King Prout
As long as you are on this thread posting comments to me I am certainly free to post back comments.

So, let me throw this to you ~ how many 80 year olds in the early 60s were at the top of their form on plate tectonics?

1, 2?

Ain't many.

Odds are they were much more concerned with their own daily movement than with that of the continents. Bet more of them thought "incontinence" was of greater importance than "continents" anyway.

982 posted on 04/06/2006 4:01:30 PM PDT by muawiyah (-)
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To: CarolinaGuitarman

Christians are not concern with the Bible at all ~ they are concerned with the Scriptures.


983 posted on 04/06/2006 4:02:44 PM PDT by muawiyah (-)
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To: freedumb2003

Oh they are cute! I'll see about posting some pics. I just started looking into their ancestory. Here's a little info.


History and Origin of the Breed

The first true Miniature Horses originated in Europe. As early as the sixteen hundreds, these tiny equines were being bred as pets for the European nobility. Paintings and articles were featuring the Miniature Horse by 1765. Lady Estella Hope and her sisters carried on the original English lines into the mid-nineteen hundreds. Many of the smallest Miniatures in the United States are from the Hope line. Unfortunately, not all early Miniatures were pampered pets of kings and queens. Some were used to work in the English Midlands and Northern European coal mines


An interesting new application for these little, mutant horses is training them as seeing eye horses. They are as intelligent as canines, possibly even more so, they live as much as thirty years, see in color, and have a 300 degree field of vision.





984 posted on 04/06/2006 4:03:03 PM PDT by Conservative Texan Mom (Some people say I'm stubborn, when it's usually just that I'm right.)
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To: jec41

Guess dark energy and dark matter don't exist ~


985 posted on 04/06/2006 4:03:57 PM PDT by muawiyah (-)
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To: jec41

Next you are going to tell us that the mind can never be subjected to scientific inquiry or examination.


986 posted on 04/06/2006 4:05:42 PM PDT by muawiyah (-)
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To: Fester Chugabrew

Still, Fester, Heisenberg's Uncertainty Principle can be readily demonstrated ~


987 posted on 04/06/2006 4:08:00 PM PDT by muawiyah (-)
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To: muawiyah

"Christians are not concern with the Bible at all ~ they are concerned with the Scriptures."

The Scriptures are the Bible. Scripture has no meaning outside of the written Word.

And Christians believe the Bible to be objectively true.


988 posted on 04/06/2006 4:09:18 PM PDT by CarolinaGuitarman ("There is grandeur in this view of life....")
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To: muawiyah

dodger,
How many geologists were in the top of their form between 1915 and 1960?
You claimed theat NOT ONE of them EVER accepted continental drift in this time period.
You have since crawdadded off this absolutism, but have not yet admitted openly that you posted pure BS.
Do so, dodger.
or don't.
either way, you add to the public record.


989 posted on 04/06/2006 4:10:27 PM PDT by King Prout (The UN 1967 Outer Space Treaty is bad for America and bad for humanity - DUMP IT.)
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To: jec41
I wish you'd keep on your materialism-only track, or admit that we can use mathematical methods to demonstrate what your lil' friend calls "objective reality"

Somebody just tried to remove the very mother of science, to wit, mathematics, from scientific inquiry.

990 posted on 04/06/2006 4:10:37 PM PDT by muawiyah (-)
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To: muawiyah

"Somebody just tried to remove the very mother of science, to wit, mathematics, from scientific inquiry."

For a very good reason. Math isn't science, and science isn't math. Science deals with the physical world; math with logical constructs.


991 posted on 04/06/2006 4:12:05 PM PDT by CarolinaGuitarman ("There is grandeur in this view of life....")
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To: muawiyah
Guess dark energy and dark matter don't exist ~

Both are hypothetical and are a matter of mathematical physics.

992 posted on 04/06/2006 4:12:25 PM PDT by jec41 (Screaming Eagle)
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To: CarolinaGuitarman
Not everything in the Bible is "scriptural", nor are all the "scriptural" elements in the Bible of interest to all Christians.

When it comes to Jehovah's Witnesses, for example, where the Bible has text that differs from their vision of "scripture" they rewrite it!

I suspect you are trying to apply a traditional Jewish approach to the Torah to what Christians think of as the Bible.

Christians simply do not handle the Bible the same way traditional Jews do the Torah. Besides their being different books (or collections of books), we really do have two different religious traditions involved.

It is not possible to discuss the Bible as Torah with any Christians I know of unless the Christian Hebrews do that, and I know some of them, and I don't recall them doing so.

993 posted on 04/06/2006 4:15:15 PM PDT by muawiyah (-)
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To: betty boop; Alamo-Girl; grey_whiskers

*shrugs*

the "lie" is an accusation levelled by literalists - either Genesis is 100% factual, or God Lied: Either the evidence does indeed show what science says it shows and the book is a lie, or the book is true and the evidence is an enormous lie that has led scientists astray. Either way, if they admit that the evidence does not square with Genesis 100%, then God lied. They therefore insist that the evidence MUST square with Genesis and see all natural science to be an attack on Genesis and, by proxy, against God.

It don't have to be so.

While the alternative I posted would not lend support to Genesis-literalism, it does quite adequately resolve the supposed conflict between recent divine Creation and the evidence embedded in the natural universe which points to an extensively ancient orgin. And it negates the "lie" problem: Does an author "lie" to his characters by setting the story in a well developed world? No. Of course not.


994 posted on 04/06/2006 4:20:41 PM PDT by King Prout (The UN 1967 Outer Space Treaty is bad for America and bad for humanity - DUMP IT.)
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To: Sofa King; yellowdoghunter
"There is nothing humble about thinking that the only knowledge that exists is that which you personally posses. Musical theory is quite real, and I know this from experience."

Excuse, please. Can't tell for sure, but I think it possible that while you are speaking of one or more of several music theory subjects, yellowdoghunter is actually talking about music appreciation, which can be considerably a less demanding part of the musical discipline.

995 posted on 04/06/2006 4:21:18 PM PDT by YHAOS
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To: William Terrell
The teaching of evolution is used for the point of being able to state that the world exists without a creator. That has been so stated by all the "fathers" of evolution.

That would be inaccurate. For example, Darwin said, in the last sentence of the 6th Edition of On the Origin of Species:

"There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone circling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved."

996 posted on 04/06/2006 4:21:20 PM PDT by Lurking Libertarian (Non sub homine, sed sub Deo et lege)
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To: muawiyah
Next you are going to tell us that the mind can never be subjected to scientific inquiry or examination.

Only your opinion would suppose that. We already have IQ tests, psychology, and psychiatrists.

997 posted on 04/06/2006 4:22:43 PM PDT by jec41 (Screaming Eagle)
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To: muawiyah
Not everything in the Bible is "scriptural", nor are all the "scriptural" elements in the Bible of interest to all Christians."

But all of Scripture is in the Bible. At least to most Christians.

"When it comes to Jehovah's Witnesses, for example, where the Bible has text that differs from their vision of "scripture" they rewrite it!"

They're subjectivists like you! :)

"I suspect you are trying to apply a traditional Jewish approach to the Torah to what Christians think of as the Bible."

No, I am saying what Christians believe.

"Christians simply do not handle the Bible the same way traditional Jews do the Torah. "

And yet they believe it is objectively true.

"Besides their being different books (or collections of books), we really do have two different religious traditions involved."

That's nice, but irrelevant to what I said.

"It is not possible to discuss the Bible as Torah with any Christians I know of unless the Christian Hebrews do that, and I know some of them, and I don't recall them doing so."

But you can discuss it as objective truth with no problems.
998 posted on 04/06/2006 4:22:56 PM PDT by CarolinaGuitarman ("There is grandeur in this view of life....")
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To: Conservative Texan Mom

Thats interesting about the miniature horses...where my mom lived in California, the people who lived in back of her, had a huge number of miniature horses....I used to like it in the spring, when the new little miniature horses were born...they were so dang cute, and spent all day in the back field of the ranch(which ran right up to my parents fence line), and ran and played all day long...some were so tiny, they were not much bigger than a large dog...

I actually saw something on Tv, about using these miniature horses as seeing eye horses...this particular seeing eye horse, was wearing something like jogging shoes on his hooves, so that he would not slip on the slippery floor, when going through an airport...

I have worked for years in nursing homes...we always had a group of people who would come in about once a week, and they would bring in animals for the residents to pet and fondle and play with...usually they brought in the usuals...dogs, cats, birds, and bunnies...but one day, I was passing in front of the front door, and noticed a miniature horse standing there..I speeded onto the nurses station, and informed the charge nurse that there was a horse standing at the front door...she looked at me as if I was insane...she felt my head, and asked me if I was ill and hallucinating...No, I reassured her, come and look...sure enough, there stood a miniature horse, ready for his nursing home visit...

The residents loved that little miniature horse, he quite the big hit...he was invited back for several more visits...anyone can bring in a cat or dog, or bird, or bunny, but our residents felt extra special, with a visit from a miniature horse...


999 posted on 04/06/2006 4:25:32 PM PDT by andysandmikesmom
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To: CarolinaGuitarman; muawiyah
CG, I believe he refers to this.
not "very good reason" at all.

If I am correct, in that that post is what he refers to, then muawiyah would have done well to give you a link to that whopper, so you would have been able to easily see what he was talking about.

1,000 posted on 04/06/2006 4:26:42 PM PDT by King Prout (The UN 1967 Outer Space Treaty is bad for America and bad for humanity - DUMP IT.)
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