BLOOMINGTON, Ind. — A popular view among evolutionary biologists that fundamental genes do not acquire new functions was challenged this week by a new study in the Proceedings of the National Academy of Sciences.
Indiana University Bloomington biologist Armin Moczek and research associate Debra Rose report that two ancient genes were "co-opted" to help build a new trait in beetles — the fancy antlers that give horned beetles their name. The genes, Distal-less and homothorax, touch most aspects of insect larval development, and have therefore been considered off-limits to the evolution of new traits.
In the two horned beetle species Moczek and Rose studied, the genetic sequences of Distal-less and homothorax were hardly different, suggesting the two genes have retained their unique identities because of selective pressures not to change. What changed was not the genes themselves, but when and where they are turned on.