The new finding may explain why female starlings take singing talent into account when choosing their mates and is an important first step towards proving a decade-old theory that suggests evolution has found a way to stop male birds from engaging in false sexual advertising.
The theory, which is known as the Immunocompetence Handicap Hypothesis, or ICHH, proposes that males of lesser reproductive quality are prevented from cheating producing a signal that falsely indicates high reproductive quality by some cost associated with producing that signal, explains Deborah Duffy, lead author on the new paper.
Duffy, a recent Ph.D. graduate of Johns Hopkins, is now a postdoctoral fellow at Indiana University. She is co-author with Greg Ball, professor of psychological and brain sciences in the Krieger School of Arts and Sciences at Johns Hopkins, of a paper published in the April 22 issue of The Proceedings of the Royal Society of London.
Understanding the function of mate choice is essential to understanding evolution, Ball says. Females clearly have an important role in mate selection in the wild, and this selection process has a big effect on what genes will appear later in the population.
Ball finds the link between mate selection and the immune system particularly intriguing.
Understanding how this variation in immunocompetence is regulated and maintained could be very valuable in our quest to understand the factors that control the immune system, he says.
When they proposed the Immunocompetence Handicap Hypothesis in 1992, researchers Ivar Folstad and Andrew John Karte
Contact: Michael Purdy
Johns Hopkins University