Newly found species fills evolutionary gap between fish and land animals

EurekAlert (AAAS) ^ | 05 April 2006 | Staff

[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.

[andysandmikesmom]

Its quite obvious, that you have no idea what I am talking about, and that you have no real intention to make further serious inquiries...so be it...you fail to understand that when studying anything scientific, it is best to understand what the words mean in the 'scientific' context...'willfull ignorance' is a phrase that has been used many times on the various Crevo threads, and you certainly display as such, and seem happy doing so...good luck with that, you will need it...

[PatrickHenry]

Nice prime!

[Gumlegs]

The compliment of a true connoisseur is the greatest of all.

[VadeRetro]

Again, this is a recent discovery.

Yes. Back around 1965, I can remember my High School Biology teacher intoning, "The human body contains hundreds of cells, class! Perhaps over a thousand!"

[js1138]

Science had advanced since my day. Back in 1959, we were taught that the body contained not more than a dozen cells. I don't know where we;d be without creation science.

I think everyone should take note that we are not engaging in name calling here. We are actually commending a creationist for bringing this advanced science to our attention.

[VadeRetro]

Computers were important in all this. Helped us to count higher.

[Coyoteman]

The evo-freakboys...

That list was based on one I put together from my own research and study, and after some modification I am still the primary one to post it.

Personal insults like this do you no credit.

[andysandmikesmom]

Are there no evo-freakgirls?

[Gumlegs]

It's a good thing only evolutionists resort to personal insults. Imagine what she'd call you otherwise.

[Coyoteman]

Nice piece discussing the use of theory in science.

I was not familiar with it so I looked it up. The URL is:

http://www.csicop.org/specialarticles/terminology.html

Thanks!

[andysandmikesmom]

Your post #1291, and the link to the article are appreciated by me...its a very interesting read...I especially like the last paragraph, where it is talked about someone throwing on a white lab coat, and spouting some pseudo-scientific jargon about something or another...this description reminds me of some of the speakers on the 'CreationNetwork' on TV....they try to look all important, and try to actually appear to be somewhat scientifically literate, yet when one breaks down what they are actually saying, all it comes down to is that they are simply attempting to discredit evolution with their word tricks...

Sometimes its actually hard to gauge exactly what they are saying, because every few minutes, the discussion is interrupted by a series of 'testimonials' from their viewers about what a great job they are doing, or a call for people to buy any or all of the various 'tape', 'CDs', 'books', and other materials they have...its more a ploy for getting money, than actually providing any scientific research....but they are adept at throwing out what sound like good scientific terms...

[Ichneumon]

B) Darwin convinced scientists to believe his theory based on antiquated information, at that time, like we only have one cell, when we really have trillions, and when there are new discoveries, evo scientists just change the theories.

Are you really this stupid? Do you actually believe that there was a time when anyone, anywhere, ever believed that the human body "only has one cell"? Much less in 1859, centuries after the first discovery of the cell?

Clue for the clueless: From the very first moment cells were first discovered, thousands of them were visible in the tiny bit of tissue under that primitive microscope, and their microscopic size was clearly understood. So what kind of moron today would be able to swallow the idiotic notion that anyone back then would ever have been dense enough to say, "hey, I'll bet the human body is only made of one of these microscopic things"...

Oh, wait, you're an anti-evolutionist -- so you're able to believe three transparently idiotic and illogical things before breakfast. Forget I asked.

And to make it clear that Darwin was well aware that bodies are made up of multiple cells:

"We need not here consider how the bodies of some animals first became divided into a series of segments, or how they became divided into right and left sides, with corresponding organs, for such questions are almost beyond investigation. It is, however, probable that some serial structures are the result of cells multiplying by division, entailing the multiplication of the parts developed from such cells."
Charles Darwin, "On the Origin of Species", 1859

Is being grossly ignorant of science, scientific knowledge, and its history, a *requirement* for being an anti-evolutionist? It sure seems to be.

[PatrickHenry]

Are you really this stupid? Do you actually believe that there was a time when anyone, anywhere, ever believed that the human body "only has one cell"? Much less in 1859, centuries after the first discovery of the cell?

I believe in the one-cell theory. Teach the controversy!

[Ichneumon]

It is true that everyone starts out as a single cell, but I suppose the stork theory is taught by anti-evolutionists.

Ovulation versus cretinism

Two different theories exist concerning the origin of children: the theory of sexual reproduction, and the theory of the stork. Many people believe in the theory of sexual reproduction because they have been taught this theory at school.

In reality, however, many of the world's leading scientists are in favour of the theory of the stork. If the theory of sexual reproduction is taught in schools, it must only be taught as a theory and not as the truth. Alternative theories, such as the theory of the stork, must also be taught.

Evidence supporting the theory of the stork includes the following:

1. It is a scientifically established fact that the stork does exist. This can be confirmed by every ornithologist.

2. The alleged human foetal development contains several features that the theory of sexual reproduction is unable to explain.

3. The theory of sexual reproduction implies that a child is approximately nine months old at birth. This is an absurd claim. Everyone knows that a newborn child is newborn.

4. According to the theory of sexual reproduction, children are a result of sexual intercourse. There are, however, several well documented cases where sexual intercourse has not led to the birth of a child.

5. Statistical studies in the Netherlands have indicated a positive correlation between the birth rate and the number of storks. Both are decreasing.

6. The theory of the stork can be investigated by rigorous scientific methods. The only assumption involved is that children are delivered by the stork.

(Original version by Erkki Aalto, Dept. of Obstetrics, Gynaecology and Stork Science, University of Helsinki --- English version by Jopi Louko, Institute of Stork Research, University of Alberta)

[js1138]

I really have mixed feelings about enjoying a Tom Tomorrow cartoon. I can only compare it to liking Eric the Viking with Tim Robbins.

[PatrickHenry]

The scientific case against Craterism

1. Meteor craters have not been observed to happen, now or in the past.
2. Meteor craters have never been reproduced in the lab, and are thus not scientific.
3. Thomas Jefferson said: "Gentlemen, I would rather believe that two Yankee professors would lie than believe that stones fall from heaven."
4. The odds against a random rock falling from the sky, striking the earth, and making a crater are astronomical.
5. The second law of thermodynamics prohibits meteor craters.
6. Meteor craters are not mentioned in the bible, nor are "rocks from the sky."
7. Craterism is a product of materialism and a Godless, naturalistic worldview.
8. Belief that rocks can fall from the sky promotes hedonism and amoral, animalistic behavior.
9. Craterism makes no predictions and is untestable; it is therefore not scientific.
10. Craterists can produce micro-craters, but have no evidence of macro-cratering.
11. Aristotle didn't believe in Craterism. Nor did Galileo, Newton, or Einstein.
12. Einstein even said: "God does not play dice!" Are you smarter than Einstein?
13. Scientists are abandoning craterism because they know it is not supported by evidence.
14. Anyone who thinks there are rocks in the sky has rocks in his head.
15. It takes more faith to believe in Craterism than it does to believe in the Tooth Fairy.
16. More and more scientists are turning to "Intelligent Crater" theory (IC). Craterism is a theory in crisis!

[andysandmikesmom]

Well, now, you have gone and done it...introduced the stork 'theory'...when I was a little girl, my grandmother assured me, that when she had her babies(this was of course, back in the old days, the 1920's and her babies were delivered at home by the visiting doctor), those babies actually were brought into the house, by the doctor in his little black bag...that was her 'little black bag' theory of where babies came from...I used to wonder, did she think I was really stupid enough to swallow that story?

So now, here are three 'theories' of where babies come from...take your pick...they come as a result of a)..sex...b)the stork...c)the doctors little black bag...

I am sure there are many more other various 'theories' as to where babies come from...

[Sun]

You missed the point. I was asked for ONE scientist, and provided 700.

Also, just because THIS news story shows 700 does not mean that it is limited to 700.

I have other news stories besides this one.

Sometimes, though, people don't really like to hear the truth.

[Sun]

Thanks for the article, but I'm just looking for an answer that shows that one species can become an entirely different species.

[Sun]

Maybe we IDers should have our very own dictionary, too.