If you drive into the high veld country an hour northwest of Johannesburg, South Africa, you might not even notice when you cross into the Cradle of Humankind. The reason 180 square miles of open grasslands and scattered acacia and stinkwood trees have been given such a resonant honorific—it’s a World Heritage site, no less—lies mostly hidden underground, in the fossil-rich labyrinth of caves and sinkholes that riddle the limestone bedrock. On Thursday, scientists announced a new offering from the Cradle of Humankind: an ancient species called Homo naledi. Judging by the features of the fossil bones, H. naledi may indeed be one of the earliest members of our genus. So are these rolling hills truly the birthplace of