BOB HIRSHON (host):
Speedily evolving lizards. I’m Bob Hirshon and this is Science Update.
The tiny green anole lizard is native to the southeastern United States, but the invasive brown anole from Cuba has also taken hold. In the journal Science, UT Austin biologist Yoel Stuart and his colleagues report that green anoles may be rapidly evolving as a result: Where the two species co-exist, the green anoles live higher in trees, and have significantly larger toe pads.
YOEL STUART (University of Texas, Austin):
What we’ve shown is that evolution can be quite fast when selection is strong and when there’s variation for selection to act on.
In fact, the toe pads changed in only twenty generations, and other experiments showed that the change was genetic, and not just a result of climbing behavior. Stuart say the finding offers hope for some native species threatened by introduced ones: if they evolve that rapidly, maybe they can avoid being out-competed into extinction. I’m Bob Hirshon, for AAAS, the science society.