Editorial - Transitional fossil supports evolution
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Discovery of evolutionary link was a scientific inevitability
by Steve Rissing (biologist, Ohio State University)
(Columbus Dispatch, 4/18/2006)
People in the know were not surprised or any more certain about the
dangers of smoking when specific molecules were finally linked to
lung cancer. They were predicted by earlier research and careful
searching found them.
So it was, last week, when the journal Nature reported the discovery
of a transitional fossil between fish and tetrapods, fourlegged
animals that live on land. Such fossils were predicted by earlier
research and careful searching found them.
In a powerful display of the predictive power of paleontology as
science, a team of researchers led by Daryl Shubin of the University
of Chicago decided to search for just such fish-tetrapod
transitional fossils in exposed layers of 375-million-year-old rocks
from ancient, shallow river beds.
Rocks from the era just before tetrapods are exposed on Ellesmere
Island in northern Canada. While only 600 miles from the North Pole
now, these rock layers provide a snapshot of past equatorial
environments first inhabited by tetrapods.
The new fossil species, Tiktaalik roseae, described from a number of
specimens collected since 1999, likely populated shallow waters.
While it has fishlike characteristics such as fins and scales,
Tiktaalik also has forelimbs with effective wrists, elbows,
shoulders and digits.
These and ribs stronger than those of similarly sized fish suggest
Tiktaalik spent considerable time on land.
The head resembles that of a crocodile with eyes and snout on top.
Some aspects of Tiktaalik's gills, while similar to those found in
earlier fish, display changes suggesting the eventual ear structure
But, Tiktaalik displays no really new characteristics. All of its
features, fish or tetrapod, have been found before, just never in a
single fossil species.
That convergence in a single species provides more strong support
for current hypotheses of animal evolution.
Nonetheless, the discovery of Tiktaalik should come as no surprise.
Like comets traveling the solar system, we know they are there
even if we are not sure of their individual form.
Discovering Tiktaalik is like hitting a comet with a space probe,
which we've also done recently.
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Comment: While many creationists continue spouting their lie that
transitional fossils don't exist, the facts demonstrate otherwise.
- Todd Greene
Discovery put creationist on the defensive
by Martin Brazeau (biologist, Uppsala University [Sweden])
(Columbus Dispatch, 5/7/2006)
It appears that creationist Mark Looy of the Answers in Genesis
ministries was pretty badly stung by the April 12 Dispatch
editorial "Evidence mounts" on the fossil Tiktaalik roseae, the now
famous fish-to-land intermediate. Creationists are having a hard
time trying to explain this one away, as we can see in Looy's April
29 letter to the editor. As a paleontologist who works on similar
animals and who has examined the Tiktaalik fossils firsthand, I
comment on Looy's letter.
In writing, "There is a fish called a coelacanth" that "has the same
kind of lobe fins as Tiktaalik. . . . It eventually was determined,
however, that the coelacanth used those lobe fins for better
maneuvering through the water, not for walking," Looy simultaneously
created the impression that the scientists who studied Tiktaalik
were unaware of coelacanths and that there are virtually no
differences in the fin-limb of Tiktaalik and that of a coelacanth.
Of course, if he had read the original papers, he should have
realized that what makes Tiktaalik so special is the number of ways
in which it is different from other lobefinned fishes, not only in
limbs but in its skull and ribs. To make matters worse for
creationists, those differences come in the form of similarities
The most baffling comment came when Looy wrote that "the bones in
the fins of both the coelacanth and the new fossil are imbedded in
the muscle and are not attached to the axial skeleton, which you
would have in a reptile or an amphibian." He should pick up a basic
anatomy textbook: The front limbs of amphibians don't have such a
I'm sorry to bother Dispatch editors and readers with mundane
details of anatomy, but the good folks at Answers in Genesis forgot
to include them. The irony is that this group is notable for its
position that evolutionists and creationists have the same evidence,
but we just interpret them through different preconceived
worldviews. If that's so, why did Answers in Genesis have to distort
reality so much?
You might want to consider and comment on Dr. Brad's analysis of the
recent announcements regarding that thingy. It can be found at:
Like Veto Roley, it appears Dr. Brad uses a definition which simply
precludes the possibility of there being any transitional fossils. Of
course, his article also says many other things as well.
- --- In Maury_and_Baty, Robert Baty wrote (post #7860):
> Todd,Actually, I'm going to point this out to Martin Brazeau, who is
> You might want to consider and comment on Dr. Brad's analysis of
> the recent announcements regarding that thingy. It can be found
> Like Veto Roley, it appears Dr. Brad uses a definition which
> simply precludes the possibility of there being any transitional
> fossils. Of course, his article also says many other things as
eminently more qualified to discuss the details than I am. I'll be
asking him if he'll dissect Brad Harrub's article, and if I can
publish his critique on my website (even though I suspect, if he
does it, that he'll have it in his blog as well).
- Todd Greene