Side-blotched lizards spend their year on earth looking to reproduce, and their strategies have lessons about evolution. An article in the May 9 edition of the Proceedings of the National Academy of Sciences provides the first genetic evidence of a trait that the animals recognize and use even if that trait seems on the surface to be counterproductive.

Cooperation is a tricky thing in terms of evolutionary theory, said Andrew McAdam, an assistant professor of fisheries and wildlife and zoology at Michigan State University and one of the papers authors. The question then is why do some organisms cooperate when it seems like being selfish should be the best strategy?

Turns out, its all in the genes.

For two decades, Barry Sinervo from the Department of Ecology and Evolutionary Biology at University of California Santa Cruz (the studys lead author) has been studying side-blotched lizards of the Central Valley of California, funded by the National Science Foundation. Males break down into three throat colors, flagging different behaviors, which Sinervo has discovered follow rock-paper-scissors cycles of lizard lust.

Orange-throated lizards are the big bullies, roaming far from home to raid female territories and mate. They generally beat blue-throated lizards, the stay-at-home dad types. The blues stick close to home to protect females and have a buddy system. One blue-throat will do battle with the orange-throat, enabling his buddy stay fit and mate. McAdam explains that the altruistic blue-throat does this, even though as a result he will sire few, if any, offspring.

The yellow-throated lizards are sneakers they casually sneak into female havens an
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Contact: Sue Nichols
nichols@msu.edu
517-353-8942
Michigan State University
2-May-2006