White Lizards Evolve In New Mexico Dunes
By HENRY FOUNTAIN
Published: January 4, 2010
http://graphics8.nytimes.com.nyud.net:8090/images/2010/01/05/science/05oblizard/popup.jpgErica Bree Rosenblum/University of Idaho
Several lizard species that are dark have developed white skin in the White
Sands of New Mexico.
The White Sands of New Mexico are a good place to study evolution in progress. One reason is that the terrain, gypsum dunes white as a sheet of paper, is so different from the surrounding area. Another is that the dunes formed only about 6,000 years ago.
“From an evolutionary perspective, that’s really the blink of an eye,” said Erica Bree Rosenblum, a professor at the University of Idaho who has been studying evolution at White Sands for much of the past decade. Her focus has been on three lizard species that elsewhere are dark skinned but in White Sands have each evolved a white-skinned variety that makes them hard to find. “It’s really obvious what’s happened,” Dr. Rosenblum said. “Everybody got white so that they could better escape from their predators.” It’s a great example of convergent evolution, of species independently acquiring the same traits.
One question about convergent evolution is the mechanism by which it happens. Sure, these three lizards all developed white skin, but did they do it in the same way? Dr. Rosenblum and her colleagues have provided answers to this question in a paper in The Proceedings of the National Academy of Sciences.
“At first blush it seems like the answer is yes,” she said. In at least two of the lizard species, the researchers found that mutations on the same gene, linked to the production of the skin pigment melanin, were responsible.
More:
http://www.nytimes.com/2010/01/05/science/05oblizard.html?ref=science