Posted on 04/02/2004 4:25:18 PM PST by 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.
The creationist movement also does not like to talk about the scientists who leave after being given the opportunity to do real field research. In 1957, the Geoscience Research Institute was formed in order to search for evidence of Noah's Flood in the geological record. The project fell apart when both of the creationists involved with the project, P. Edgar Hare and Richard Ritland, completed their field research with the conclusion that fossils were much older than allowed under the creationist assertions, and that no geological or paleontological evidence of any sort could be found to indicate the occurrence of a world-wide flood. (Numbers, 1992, pp 291-293) Hare concluded, "We have been taught for years that almost everything in the geological record is the result of the Flood. I've seen enough in the field to realize that quite substantial portions of the geologic record are not the direct result of the Flood. We have also been led to believe . . . that the evidence for the extreme age of the earth is extremely tenuous and really not worthy of any credence at all. I have tried to make a rather careful study of this evidence over the past several years, and I feel that the evidence is not ambiguous but that it is just as clear as the evidence that the earth is round." (cited in Numbers, 1992, p. 294) Ritland, for his part, pointed out that Morris's book The Genesis Flood contained "flagrant errors which the uninitiated person is scarcely able to detect". (cited in Numbers, 1992, p. 294) Ritland concluded that further attempts to justify Flood geology would "only bring embarrassment and discredit to the cause of God". (cited in Numbers, 1992, p. 293)Who Are the Creation Scientists?
Quite modest in size and scope, and still seriously padded with irrelevant and fallacious entries!
"Invented" means there was intelligent design. Enviros, please try to be just a tad more consistent with your use of the english language. "Eyes seem to have developed independently by accident several times" would be a more intelligent and precise construction.
ER 1470 (Homo rudolfensis) is pretty good. Half the creationists scream it's "An ape! Just an ape!" The other half screams "It's a man! Just a man!"
Note the table about halfway down this web page.
There is only one thing a creationist will never say: "Thank you for pointing out my error. I was misled by an unreliable source. I won't repeat that mistake."
The problem comes when you pretend that, since "science keeps changing its story," phlogistion theory, or flat earth theory might be due for a comeback. Hemlines go up and down, but science converges on an ever more accurate model of reality. It is following this increasing accuracy, not fashion, when it makes changes. We really have learned some things, which is why phlogiston theory won't be coming back. Neither will Global Flood Geology.
In the restaurant of your intellect, we'd all starve.
One of the best, but most misunderstood, of Emerson's sayings in Self-Reliance:
A foolish consistency is the hobgoblin of little minds, adored by little statesman and philosophers and divines.
First, we have a fish, with fins attached to its head.
Then, we have an amphibian, with well-developed powerful forearms with extensive areas for attachments of muscles at the shoulder.
According to the evolutionists, what is a "transitional" form? ......... Why it's a creature "with well-developed powerful forearms with extensive areas for attachments of muscles at the shoulder" (now where did I just hear that?).
A "transitional form" would be one with powerful forearms attached to the head, or one with fins attached to the shoulder.
The evolutionist view predicts that we should find these kinds of fossils in various stages of development. The creationist view predicts that we should find them mysteriously missing.
I haven't been much of an "enviro" for a quarter century or more. As far as avoiding anthropomorphic language, it's more fun to use it and watch the arguments from semantics that follow. I like the screams that result when I use the Dawkins quote "Evolution is smarter than you are."
That's what happens when you wake up from your nap and head straight for FR without a cup of coffee. Well... you know what I meant.
They've been saying that since 1859, when there really wasn't much fossil progression to show. They keep saying it, but they have to ignore an awful lot that has turned up since then. It doesn't matter how much we actually find, the mantra never changes because it can't.
...but you can't make him think.
I like the fact that this shows, once again, (as in his selection of The Blind Watchmaker" as title for his argument), that Dawkins is incapable of speaking of evolution without packaging it in terms of an Intelligent Designer.
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