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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

PH saw fit to put it in his list of "Brain on Creationism" quotes, IIRC.

No, that must be another one. I'm referring to a discussion I had with you where you stated this. If you make me dig it up and then equivocate and deny it you won't be moving up on my list of favorite people.

So why not just start with whether or not you recognize a difference between the natural and supernatural. Do you?

1,041 posted on 04/06/2006 7:04:06 PM PDT by ml1954
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To: Fester Chugabrew
And see, who says philosophy has come up with no new info in years and years. Perhaps it has, it's just being ignored.

You know what else I find interesting, This! Morality, values, virtues, and ethics, that are determined to be beneficial to life and happiness, and are derived from purely logical, philosophical reasoning. (that means no inference of faith, deity, mysticism, or other irrational reasoning), are remarkably similar to those that are consistent with Christianity, and 7 of out of the Ten commandments. The first three of the Ten Commandments address reverence toward God.
1,042 posted on 04/06/2006 7:06:18 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: muawiyah

Well, what I really want to know, scientifically of course, is how many of McNamara's bricks were discarded, and how thick is each one.


1,043 posted on 04/06/2006 7:11:13 PM PDT by Fester Chugabrew
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To: Fester Chugabrew
I still have several hundred of them. They are standard facing bricks. Of course MacNamara being MacNamara he had a custom beige sand topcoat baked on. It's tended to fall off over the years.

I, and many of my neighbors, have enjoyed them immensely ~ frequently around the 4th of July ~

1,044 posted on 04/06/2006 7:13:04 PM PDT by muawiyah (-)
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To: Conservative Texan Mom
You know what else I find interesting, This! Morality, values, virtues, and ethics, that are determined to be beneficial to life and happiness, and are derived from purely logical, philosophical reasoning. (that means no inference of faith, deity, mysticism, or other irrational reasoning), are remarkably similar to those that are consistent with Christianity, and 7 of out of the Ten commandments. The first three of the Ten Commandments address reverence toward God.

Do they apply to everyone, every time, and everywhere. Or to just someone, sometimes, and somewhere. Or can you observe these things and the opposite.

1,045 posted on 04/06/2006 7:14:10 PM PDT by jec41 (Screaming Eagle)
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To: Fester Chugabrew

(Intelligent design fits objective reality handily from both an inductive and deductive standpoint. It takes a philosophy of some kind to explain it away. Let an evolutionist fill in the blank: "The presence of organized matter performing specific functions is best explained by . . ."

They do not have an answer. They pretend such an answer resides outside the realm of science altogether. To a degree it resides outside the realm of absolute certitude in this life. So do many other things science contends with. Science does not even know how many rubber bands are manually discarded each year. I hardly think it capable of reconstructing genetic history on the basis of morphological similarities.)




Is this the part where someone says, "evolution doesn't address this"?


1,046 posted on 04/06/2006 7:15:55 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: ml1954
Don't care to make you dig something up, and don't want to pin you into some kind of corner. I just don't think the distinction between natural and supernatural is scientifically useful because it cannot be scientifically determined. I do not consider it unnatural, or supernatural, for intelligent design to take place on any scale, even a scale beyond my meager understanding. Intelligence and design are natural things, AFAIK.
1,047 posted on 04/06/2006 7:16:26 PM PDT by Fester Chugabrew
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To: PatrickHenry


1,048 posted on 04/06/2006 7:20:19 PM PDT by Central Scrutiniser (No one censors speech they agree with.)
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To: Conservative Texan Mom
Is this the part where someone says, "evolution doesn't address this"?

Yes, and by default. This is the part where evolution throws up it's hands and says "We cannot know, and we do not want to know." But it still wants to have a front row seat in public schools and by law exclude any other suggestions.

1,049 posted on 04/06/2006 7:21:08 PM PDT by Fester Chugabrew
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To: King Prout; grey_whiskers; Alamo-Girl; marron; hosepipe; TXnMA; gobucks; Slingshot
either Genesis is 100% factual, or God Lied

Oh, thanks King Prout, for clearing that problem up for me! Yet notwithstanding your having done so, may I say this particular line of reasoning makes absolutely no sense to me at all in the first place?

How could any Christian, of whatever denomination, say that our God on Whom salvation absolutely depends, "lies???" This makes no sense to me at all. FWIW.

*shrugs*

Thanks for the excellent conversation, KP.

1,050 posted on 04/06/2006 7:26:27 PM PDT by betty boop (The world of Appearance is Reality’s cloak -- "Nature loves to hide.")
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To: Fester Chugabrew

I just don't think the distinction between natural and supernatural is scientifically useful because it cannot be scientifically determined.

So how is it determined?

1,051 posted on 04/06/2006 7:26:49 PM PDT by ml1954
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To: Conservative Texan Mom

Sounds like you have a place full of critters...sounds like a lot of hard work, but also sounds like a lot of fun...I love critters all around, so what you describe sounds heavenly...


1,052 posted on 04/06/2006 7:26:59 PM PDT by andysandmikesmom
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To: Conservative Texan Mom

Natural law is ingrained, albeit darkly, in the hearts of all people. So is religion. Science takes second place, though certain people would like to think otherwise.


1,053 posted on 04/06/2006 7:27:56 PM PDT by Fester Chugabrew
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To: Fester Chugabrew
At bottom, science is ill fit to determine whether everything is supernatural or not. Right? Or have you come across the scientific method for determining what is or is not supernatural?

What is better fit than science to determine this and how would it do so? The method of science was specifically designed to determine the difference between faith and belief and fact. Before the scientific method everything was faith and belief.

1,054 posted on 04/06/2006 7:30:51 PM PDT by jec41 (Screaming Eagle)
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To: betty boop

The basic Genesis story predates the existence of the Hebrews anyway. It's all "Antedeluvian" (in the old Biblical dating scheme) for one thing, and with the whole world destroyed, it's really hard to go back and secure adequate witnesses.


1,055 posted on 04/06/2006 7:30:55 PM PDT by muawiyah (-)
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To: Conservative Texan Mom

The presence of organized matter performing specific functions is argued by anyone of opinion.


1,056 posted on 04/06/2006 7:35:52 PM PDT by jec41 (Screaming Eagle)
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To: Fester Chugabrew
Don't care to make you dig something up, and don't want to pin you into some kind of corner. I just don't think the distinction between natural and supernatural is scientifically useful because it cannot be scientifically determined. I do not consider it unnatural, or supernatural, for intelligent design to take place on any scale, even a scale beyond my meager understanding. Intelligence and design are natural things, AFAIK.

It has already been defined and determined. One is fact and one is faith and belief. It is adhered too by both philosophy and science.

1,057 posted on 04/06/2006 7:40:07 PM PDT by jec41 (Screaming Eagle)
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To: hosepipe; Lurking Libertarian; Alamo-Girl; marron
If true then Darwin was an ID'er.. You know intelligent design.. before it was called that.

That's exactly how I read the statement, hosepipe! LOLOL!!!

Here's a simple question on this theme: How did a "simple beginning" give rise to the fascinating multiplicity of what we observe with our own eyes every day in the world around us?

I conjecture even Darwin did't have the last word on that question, let along imagine that he did to begin with.

I imagine Darwin was a creature of his age. Probably as honest as they come, under the local conditions then acknowledged by the contemporary cognoscienti....

Am sleepy. Must go to bed. Good night, dear hosepipe!!! And pleasant dreams!!!

1,058 posted on 04/06/2006 7:41:07 PM PDT by betty boop (The world of Appearance is Reality’s cloak -- "Nature loves to hide.")
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To: King Prout; betty boop; Alamo-Girl
[ either Genesis is 100% factual, or God Lied ]

Or a range of other options like the reader missed something, misunderstood something, is dogma tied, or is metaphor challenged.. etc...

1,059 posted on 04/06/2006 7:41:24 PM PDT by hosepipe (CAUTION: This propaganda is laced with hyperbole..)
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To: andysandmikesmom
I sent you another Freepmail.

I feel like being here is a miracle. We really wanted to get out of the city. My son just turned 12. we felt like we needed to do it now, or he wouldn't associate farm life with his childhood. I know that all kinds of hilly billy things get said about Arkansas, but it is gorgeous here! We have seasons, mountains, and critters. Financially, it made no sense to move here because my husband's business was well rooted and thriving in Baytown(just outside of Houston, but it all runs together). Moving to a rural area has been a leap of faith, but it's all working out very well so far. We're very glad we did it. I have to admit though, after hearing some stories from some of the locals, some of the rumors are true.

The Freepmail tells you about a friend of mine that passed. She was a catalyst for our move somewhat. We'd been talking about it, but her passing made us realize that you've got to make the most of the time you've got, however long that is. We really wanted this for our family!
1,060 posted on 04/06/2006 7:43:15 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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