Asymmetric Warfare Between Earwigs Explored

ScienceDaily (Aug. 15, 2012) — Symmetrical looks are highly prized in the animal kingdom, but according to a new report by San Francisco State University biologists on an insect called the maritime earwig, asymmetry might come with its own perks.

Animals -- including humans -- seem to use symmetry as a shortcut for evaluating potential mates. Symmetrical features usually indicate normal development, while asymmetry could point to an underlying developmental defect that would render a mate less fit.

"The evolutionary theory that underpins symmetry in mate choice is very straightforward," said Andrew Zink, assistant professor of biology.

"Asymmetry is likely to represent a heritable defect in foraging or survival, and therefore females who pick more symmetrical males are more likely to pass on genes for success."

But the study conducted by Zink's graduate student Nicole Munoz, published August 15 online by the journal Ethology, suggests there are some instances where asymmetrical features are useful enough to be maintained among males in a population.

Continued: http://www.sciencedaily.com/releases/2012/08/120815083245.htm