SAN FRANCISCO, CALIFORNIA—Some 100 footprints near Ileret, Kenya, are thought to have been left 1.5 million years old by a hunting party made up of Homo erectus adults. “What we can say is that we have a number of individuals, probably males, that are moving across a lake shore in a way that is consistent with how carnivores move,” palaeoanthropologist Neil Roach of the American Museum of Natural History said at the annual meeting of the Paleoanthropology Society, reported in Nature. Some researchers have speculated that Homo erectus turned from scavenging to hunting to obtain more calories for their developing brains. But “hunting is a difficult thing to prove in human evolution,” Roach said. He and his team plan to study footprints left behind by subsistence hunters today in order to get a better idea of their patterns of movement for comparison. To read in-depth about the evolution of throwing, see "No Changeups on the Savannah."