Naming Evolution's Winners And Losers

Mammals and many species of birds and fish are among evolution's "winners," while crocodiles, alligators and a reptile cousin of snakes known as the tuatara are among the losers, according to new research by UCLA scientists and colleagues.

"Our results indicate that mammals are special," said Michael Alfaro, a UCLA assistant professor of ecology and evolutionary biology and lead author of the research.

The study, published July 24 in the early online edition of Proceedings of the National Academy of Sciences, also shows that new species emerge nearly as often as they die off.

Alfaro and his colleagues analyzed DNA sequences and fossils from 47 major vertebrate groups and used a computational approach to calculate whether the "species richness" of each group was exceptionally high or low. The research allows scientists to calculate for the first time which animal lineages have exceptional rates of success.

Among the evolutionary winners are most modern birds, including the songbirds, parrots, doves, eagles, hummingbirds and pigeons; a group that includes most mammals; and a group of fish that includes most of the fish that live on coral reefs, said Alfaro, an evolutionary biologist.

Science Daily Article

This is a very interesting article on the winners and losers of evolution. I can see what they have been trying to do, using biodiversity as a gauge for success though is not that exact though. Take this quote "Crocodiles and alligators are nearly 250 million years old yet have diversified into only 23 species". In my opinion this does not mean they are less successful than any mammals or birds, its just that they have not been subjected to the environmental changes other species have, so they have no need for diversification. In fact i would call them successful, they are perfectly suited to their environments a have been for 250 million years.

Very interesting find you have there, although I too would have classed things like crocodiles as the winners too. Anything that can last for as long as they have without needing to change very much has got to be a winner.

Too bad my phone won't let me look at the article though

[edit on 24-8-2009 by ShiningSabrewolf]

I think its the ability to adapt that makes one species a winner over another.

Yes!!

In your face evil reptilian overlords!!!