Marcus Kronforst (left) and Krushnamegh Kunte at Harvard’s FAS Center for Systems Biology used genetic analysis to examine the evolutionary history of the Appalachian tiger swallowtail, discovered in 2002. “Our work provides perhaps the first animal example that illustrates how hybrid species may be selectively favored when they inherit from their parent species-specific combinations of genes that underlie important ecological traits,” said Kunte, a postdoctoral fellow at the center.