Teaching Evolution

A blog devoted to teaching evolution, both in our schools and in our communities.

Wednesday, April 27, 2005

How Did Great White Sharks Evolve?

Humans have a fascination with sharks, and they're one of the best animals to study from an evolutionary perspective because they lose their teeth so often that fossils abound everywhere sharks have lived. An interesting debate is shaping up about how the Great White evolved: Is it a descendent of the megladon or the mako? Chuck Ciampaglio an assistant professor of geology at Wright State University, has some answers.

Most scientists would probably say the Great Whites evolved from the megladon line, which existed from two million to twenty million years ago. They were huge sharks, approximately the length of a Greyhound bus and possessing teeth that were up to six inches long. However, our research, which is based on analyzing fossils of several hundred shark teeth, shows that the Great White shares more similarities with the mako shark.

Researchers use uses electron microscopes to examine different designs of digital images of shark teeth. This is the kind of great research that's currently going on in the field of evolution. It's a shame that all the general public knows about evolution is that a lot of people think it's incompatible with their religious faith.


At 1:47 PM, Blogger dhodge said...

If you're interested in the evolution of sharks, you may want to check out the elusive megamouth shark. From what I understand, it's the giant squid of the shark world. I don't know if it's an evolutionary dead-end like the coelacanth, but it's at least as rare.


Post a Comment

<< Home