Posted by: Steve Coplan | April 7, 2006

The Coelacanth toppled from its perch?

Has Buffalo City lost a major tourist draw? The news that a University of Chicago evolutionary biologist has found the 375-million-year old fossil of the 'missing link' between sea and land animals could mean that the Coelacanth at a mere 70 million years old fades from its current prominent state in the popular consciousness. Buffalo City (the river port formerly known by its colonial name of East London) which was where the Coelecanth was first identified by the scientific world, could relinquish its international standing in the zoological world to the remote north of Ninavut.

The New York Times reports: "The skeletons have the fins, scales and other attributes of a giant fish, four to nine feet long. But on closer examination, the scientists found telling anatomical traits of a transitional creature, a fish that is still a fish but has changes that anticipate the emergence of land animals — and is thus a predecessor of amphibians, reptiles and dinosaurs, mammals and eventually humans."

While the 'missing link' angle makes for good marketing, the more serious articles in Nature point to a more nuanced view that suggests an inflection point rather than a marker in the ground. The fossils provide some strong hints on how the transition from land to sea happened at a morphological level, such as the development of a proto-wrist. So while this may be a useful argument against creationists who argue that that there are no transitional or mosaic fossils, the more interesting outcome is evidence to explain the mechanisms of evolution and adaptation. By developing wrists, the fish could support its weight in the shallows, where there would be less competition for food – plants and inverbetrates. Neil Shubin explains some of his deductions on this podcast.

The distinction, however, is that the Coelacanth is a living fossil.

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