The island of Madagascar — one of the last large land masses colonized by humans – -sits about 250 miles (400 kilometers) off the coast of East Africa. While it’s still regarded as a place of unique biodiversity, Madagascar long ago lost all its large-bodied vertebrates, including giant lemurs, elephant birds, turtles, and hippopotami. A human genetic study now links these losses in time with the first major expansion of humans on the island, around 1,000 years ago.