New Fossil Links Four-legged Land Animals To Ancient Fish

National Science Foundation ^ | 01 April 2004 | Staff

[PatrickHenry]

Arlington, Va.—How land-living animals evolved from fish has long been a scientific puzzle. A key missing piece has been knowledge of how the fins of fish transformed into the arms and legs of our ancestors. In this week's issue of the journal Science, paleontologists Neil Shubin and Michael Coates from the University of Chicago and Ted Daeschler from the Academy of Natural Sciences in Philadelphia, describe a remarkable fossil that bridges the gap between fish and amphibian and provides a glimpse of the structure and function changes from fin to limb.

The fossil, a 365-million-year-old arm bone, or humerus, shares features with primitive fish fins but also has characteristics of a true limb bone. Discovered near a highway roadside in north-central Penn., the bone is the earliest of its kind from any limbed animal.

"It has long been understood that the first four-legged creatures on land arose from the lobed-finned fishes in the Devonian Period," said Rich Lane, director of the National Science Foundation's (NSF) geology and paleontology program. "Through this work, we've learned that fish developed the ability to prop their bodies through modification of their fins, leading to the emergence of tetrapod limbs."

NSF, the independent federal agency that supports fundamental research and education across all fields of science and engineering, funded the research.

The bone's structure reveals an animal that had powerful forelimbs, with extensive areas for the attachment of muscles at the shoulder. "The size and extent of these muscles means that the humerus played a significant role in the support and movement of the animal," reported Shubin. "These muscles would have been important in propping the body up and pushing it off of the ground."

Interestingly, modern-day fish have smaller versions of the muscles. According to Coates, "When this humerus is compared to those of closely-related fish, it becomes clear that the ability to prop the body is more ancient than we previously thought. This means that many of the features we thought evolved to allow for life on land originally evolved in fish living in aquatic ecosystems."

The layered rock along the Clinton County, Penn., roadside were deposited by ancient stream systems that flowed during the Devonian Period, about 365 million years ago. Enclosed in the rocks is fossil evidence of an ecosystem teeming with plant and animal life. "We found a number of interesting fossils at the site," reported Daeschler, who uncovered the fossil in 1993. "But the significance of this specimen went unnoticed for several years because only a small portion of the bone was exposed and most of it lay encased in a brick-sized piece of red sandstone."

Not until three years ago, when Fred Mullison, the fossil preparator at the Academy of Natural Sciences, excavated the bone from the rock, did the importance of the new specimen become evident.

The work was also funded by a grant from the National Geographic Society.

[PatrickHenry]

Your response was lacking in substance, but you were courteous. For that I thank you.

[RobRoy]

You are welcome.

[balrog666]

Content-free placemarker.

[RightWingNilla]

He never added anything positive to any conversation, but he was certainly colorful. I think he misses me a whole lot more than I miss him.

Got that right Patrickspacealienhenry!

[Aracelis]

As I implied above, any rational reader could not come to the conclusions stated in the article based on the evidence provided there. There is no reason to point by point make that argument. The article is short, let the readers decide for themselves.

A simple click on the link provided by PH will reveal to you that this article is a press release - not a journal article. Just a "Hey guys! This is what we're up to" piece...nothing more.

[Aracelis]

Whenever you want to know why God made something, it is best to ask him. Don't ask one of the pots why the potter put a handle on one. It's not their forte'.

I do, and with great frequency. The Lord has never told me, in matters related to science, that I should just "believe" one argument or another. He has consistently told me to investigate the issues for myself. I trust Him to reveal facts to me through my coursework, field and laboratory experiences.

[Junior]

Content-free placemarker.

An ID proponent now, are we?

[PatrickHenry]

Transitional placemarker.

[Michael_Michaelangelo]

Thanks! And good luck on your exam.

If you're interested, here are a couple articles I've read recently regarding this subject:

Link

Link

Link

[js1138]

Whenever you want to know why God made something, it is best to ask him.

Good point. That and your tagline illustrate how ID is not science. ID asks the why question and expects to find the answer in the rocks, so to speak. Evolution is about how, not why.

[RobRoy]

Sounds reasonable to me. So you are not one of the Evolutionist religious zealots. Not all who study evolution are. Many are real scientists.

[RobRoy]

But all I could respond to was the article and the fact that the press release did not support the claims. My warning to lay people is to not stop at the press release and just assume it is all true.

[RobRoy]

>>Good point. That and your tagline illustrate how ID is not science. ID asks the why question and expects to find the answer in the rocks, so to speak. Evolution is about how, not why.<<

Exactly, except I would say "The study of evolution is about how, not why."

It's not the study, the facts, or even the hypotheses about evolution that concern me. It is when Religious evolutionists claim that things not seen are in fact fact. Only what has been actually observed can be described beginning with the words, "We know..." The rest is just hypothesis and must be treated as such for it's adherents to be taken seriously.

[js1138]

It is when Religious evolutionists claim that things not seen are in fact fact.

I have never seen toledo, but I accept its existence as a fact. Word games are beneath everyone's dignity.

Thousands of people in this country have been legally executed for crimes that were unwitnessed. There is a point in any scientific investigation wher rational people accept conclusions as fact.

So if you wish to argue evidince, go right ahead, but lets drop this childish pretence that you have to witness something for it to be a fact.

[js1138]

I think I just set a record for misspellings.

[RobRoy]

So if you wish to argue evidince, go right ahead, but lets drop this childish pretence that you have to witness something for it to be a fact.<<

For you it is word games. For me it is not. I am a black and white thinker and make no apologies for it. If you do not witness a thing, you do not know it to be a fact, you believe it to be a fact.

The difference is what you believe vs what you know. And if you haven't been to Toledo, you do not KNOW it exists, you simply believe it exists.

To know a thing, you must experience it. You wish to shuffle the distinction under the table. I do not. Many claimed to KNOW Piltdown was an amazing find. They were wrong, because they didn't know - they only believed.

The difference matters and can be huge!

[js1138]

So, assuming you don't still live at home, do your parents exist (or did they)?

[RobRoy]

Yes, I see them occasionally.

But if you are saying that I should believe that someone else was really my parents because of a chunk of a bone that someone used to create a full skeleton out of their imagination, I'd be hard pressed to agree with you.

If you asked me not to believe it, but to KNOW it, we would really have to part intellectual company.

[js1138]

So if the police find, say a chunk of bone buried in your yard, by your rules of evidence they are not allowed to identify it as human or non-human?

[RobRoy]

If they pay me for it, or otherwise get my permission, they can use it to make stew, for all I care.

I would have a hard time respecting them intellectually if they required me to KNOW that it was a particular thing from a time before anyone alive today existed or wrote about it. They can come up with all kinds of theories, I just don't want them cramming them down my throat as fact.

It insults me even further when they place themselves on an intellectual pillar and arrogantly state that I am stupid if I disagaree with them.

I'm not that stupid - and they're not that smart.