Flitting among the cool slopes of the Appalachian Mountains is a tiger swallowtail butterfly species that evolved when two other species of swallowtails hybridized long ago, a rarity in the animal world, biologists have found.
Flitting among the cool slopes of the Appalachian Mountains is a tiger swallowtail butterfly species that evolved when two other species of swallowtails hybridized long ago, a rarity in the animal world, biologists have found.