Lemurs first arrived on the island of Madagascar 53.2 million years ago, probably hitching a ride on a vegetation raft from mainland Africa. The island was predator free, and the lemurs evolved into an abundance of species to thrive in its various habitats—an expansion that hasn’t stopped since. Because they are all native to Madagascar, the island hosts a whopping 15 percent of all primate species. Today, three specific groups of lemurs—mouse lemurs, sportive lemurs, and brown lemurs—have very high rates of speciation, or how fast new species form. For instance, the team found that diversification among lorises, bushbabies, and galagos (lemur primate relatives) on continental Africa and Asia is much slower.