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.

[js1138]

What does your post mean?

[PatrickHenry]

Talk.origins has a long and fairly new article on the confusion surrounding Haeckel's Embryos.

[Oztrich Boy]

Well if you can't see how the Creationist rules of debate operate...

[balrog666]

Shall I declare victory and make it official?

[js1138]

I know how these threads go. Creationists bring up 100 year old controversies as if nothing has happened in the meantime. The Haeckel drawings bear the same relationship to biology as as Lowell's Mars drawings do to astronomy, and they are referenced in textbooks for the same reason. They are an interesting part of the history of science.

[PatrickHenry]

Shall I declare victory and make it official?

Wait. They still have Piltdown Man in their bag of tricks. (That's okay, we have Rev. Jim Jones.)

[fish hawk]

Stuff it!! Where your knowledge is. I wasn't talking to you anyway.

[VadeRetro]

From your link: The similarities between vertebrate embryos are real.

From 29+ Evidences For Macroevolution:

Figure 2.4.1. Cat and human embryos in the tailbud stage. A cat embryo is shown on top, a human embryo below. Note the post-anal tail in both, positioned at the lower left below the head of each. The human embryo is about 32 days old.

Ontogeny and Development of Organisms.

[VadeRetro]

Stuff it!! Where your knowledge is. I wasn't talking to you anyway.

My objection to your proposal remains as stated.

[PatrickHenry]

Stuff it!
</idiot mode>

[VadeRetro]

Stuff it!

Reality isn't everything. The Great Pumpkin is.

[PatrickHenry]

Fish --> [transitional fossil found!] --> Amphibians

Creos in panic!!! ((((Suicide watch in effect))))

TOTAL DENIAL!!! Creation "science" fails again!!!!! ##Kool aid ready###

ARRRRGGHHHH!!! </f.christian memorial mode>

[headsonpikes]

Seems to me that you miss ol' effdot. ;^)

[PatrickHenry]

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.

[Aracelis]

Post 174 "The Bible. Read it, and you won't need to read anymore."

Pst 203 "I myself love to read scientific articles and journals."

Ok, kid...which is it? Read the Bible only, or it's ok to read other stuff too? Oh wait, I forgot about the 11th Commandment. You know - the one that was chipped off when Moses' servant, Herschel, tripped and dropped the Tablets? The one that said, "Thou shalt remain ignorant." Pretty important one around here it seems.

"No I am not kidding, and don't patronize me."

If you knew RadioAstronomer, you would also know that he never patronizes...he is a scientist, and sometimes that means asking uncomfortable or seemingly simplistic questions.

"Take care wise guy."

Ibid, my previous remark. BTW, you want arrogance and wise remarks, talk to me. I'm not nearly as nice as my friend, RadioAstronomer, and certainly far more controversial.

Free Tip of the Day - You wanna be taken seriously, learn to spell.

[Aracelis]

Creos in panic!!! ((((Suicide watch in effect))))

Suicide is a sin. I refer you to the 11th Commandment, which goes into effect anytime substantial and credible scientific information is revealed.

[Aracelis]

They still have Piltdown Man in their bag of tricks.

Irrelevant, as we Piltdowns have all evolved.

[PatrickHenry]

Nice pic. Looks like someone bashed you in the eye. Not everyone likes a smart-mouth. Of course, I'm not everyone ...

[RadioAstronomer]

I agree, no creationism in our schools and no evolution either. Good start, clean slate.

*Bzzzzt*, wrong, but thank you for playing.

You may want the kids in your schools to be ignorant, however, I do not.

[js1138]

I'm not nearly as nice as my friend, RadioAstronomer, and certainly far more controversial.

Been there, done that.