Colorful butterflies share survival traits.

• Position: Hybrid Insects

Bright black-and-red butterflies that flit across the sunlit edges of Amazonian rain forests are natural hedonists, and it does them good, according to genetic data gathered by an international consortium of researchers, who discovered that different species of the Postman butterfly are crossbreeding to acquire superior wing colors more quickly. They also have a surprisingly large number of genes devoted to smell and taste.

The use of color to attract mates and fend off predators is widespread in daytime-loving butterflies, while night-flying moths are famous for having large antennae to sniff out potential mates' pheromones. Thus, researchers predicted that, because they are such visual creatures, the butterflies would not be able to smell or taste very well. "instead, we learned that they have a rich repertoire of genes for olfaction [smell] and chemosensation [in this case, taste]," says University of California, Irvine, biologist Adriana Briscoe, article coauthor. Delicate antennae contain smell receptors, and the butterflies' tiny feet hold taste buds.

Briscoe explains that additional findings by the consortium could help scientists better understand trait sharing on other species, such as Homo sapiens and Neanderthals.

Researchers first sequenced the genome of the...