Taking the long way home
The incredible journey of a colony of normally stay-at-home daddy longlegs is bucking accepted theories about how species spread to and from islands, with genetic analysis showing they reversed the normal route, island-hopping to, instead of from, a continent: Australia. The theory of island biogeography, developed in part at Harvard by eminent biologist Edward O. Wilson, says that islands are populated by species from nearby continents, with fewer and fewer species represented the farther the islands are from the mainland. But the case of a family of daddy longlegs, spiderlike creatures also called harvestmen, throws all that out the window. Graduate student Prashant Sharma, a doctoral student in organismic and evolutionary biology at the Graduate School of Arts and Sciences, spent several years collecting and analyzing harvestmen from Australia and islands across the Pacific to solve the mystery of the creatures’ origin. Species of harvestmen in the Zalmoxidae family are spread across the...