ScienceDaily (Nov. 9, 2009) Why do so many animal species -- including fish, birds and insects -- display such rich diversity in coloration and other traits? In new research, Gregory Grether, UCLA professor of ecology and evolutionary biology, and Christopher Anderson, who recently earned his doctorate in Grether's laboratory, offer an answer.
At least since Charles Darwin, biologists have noticed that species differ in "secondary sexual traits," such as bright coloring or elaborate horns, Grether said. Darwin attributed this diversity to sexual selection, meaning the traits increased an animal's ability to attract mates.