Castaway Lizards Put Evolution to the Test
by Brian Vastag
When Hurricane Frances swept through the Caribbean in 2004, it wiped out populations of little anole lizards living on seven tiny islands in the Bahamas. Instead of mourning the loss, Harvard University biologist Jonathan Losos spied an opportunity: He could, for the first time, test a controversial 70-year-old idea in evolutionary biology.
What might happen, Losos wondered, if he dropped pairs of anole lizards, castaway-like, onto each island? Would they simply go extinct? Or could the reptilian couples launch — or found — new colonies that would diverge in appearance, taking the first steps on the long road toward becoming different species?
The lizards, it turned out, thrived. After two years, one island sheltered 40 lizards descended from the first couple. More intriguingly, within just a few generations, the back legs of the lizards on all seven islands began to shrink. Shorter legs provide more agility for the lizards as they navigate the shrunken shrubbery on the tiny islands. And agile lizards can catch more insects and more easily dodge hungry birds…
(read more: Washington Post) (photo: Lanare)
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Read the paper here:
http://www.sciencemag.org/content/early/2012/02/01/science.1209566.abstract?sid=36a2d0a1-42b3-4c51-a2f4-16a689ef2209
