image: An adult Caenorhabditis elegans crawls on Serratia marcescens in a Petri dish. S. marcescens is a pathogenic bacteria that quickly kills C. elegans if eaten. This image relates to an article that appeared in the July 8, 2011, issue of Science, published by AAAS. The study, by Dr. Levi Morran of Indiana University in Bloomington, Ind., and colleagues was titled, "Running with the Red Queen: Host-Parasite Coevolution Selects for Biparental Sex." view more
Credit: Image © <i>Science</i>/AAAS