image: The male red sea urchin, Strongylocentrotus franciscanus, spawning off the coast of Bamfield, British Columbia. Field experiments demonstrated that the rate of evolution in gamete recognition proteins depends on population density. This image relates to an article in the 14 April 2006 issue of the journal Science, published by AAAS. The study, by Don R. Levitan and D.L. Ferrell of Florida State University, was titled "Selection on Gamete Recognition Proteins Depends on Sex, Density, and Genotype Frequency." view more
Credit: Image courtesy of Don R. Levitan of Florida State University, via <i>Science</I>-AAAS.