How do caterpillars acquire chubby legs: NUS scientists trace the origins to an ancient genetic program associated with crabs

Adult insects, including butterflies and moths, typically have only three pairs of legs. But the existence of extra legs in caterpillars – chubby abdominal appendeages also known as ‘prolegs’ – has long posed an evolutionary mystery to biologists.

Butterfly beginnings

Biologists from Washington University in St. Louis collaborated with a large number of butterfly and plant specialists to reconstruct the origin and global spread of butterflies. Working with researchers from dozens of countries, Michael Landis and Mariana P. Braga in Arts & Sciences helped create the world’s largest butterfly tree of life, assembled with DNA from more than 2,000 species representing all butterfly families.