By Bruce Bower
Scientists trying to untangle the human evolutionary family’s ancient secrets welcomed a new set of tantalizing and controversial finds this year. A series of fossil discoveries offered potentially important insights into the origins of the human genus, Homo. Most notably, a group of South African fossils triggered widespread excitement accompanied by head-scratching and vigorous debate.
If the discoverers of the South African fossils are right about what they have found, then at least some early members of the Homo genus possessed an unexpected patchwork of humanlike and apelike features, with legs and feet built for upright walking but shoulders, chests and hips suited to climbing trees. These ancient hominids had brains much smaller than anyone expected, housed in skulls shaped like those of later Homo species. In the year’s most intriguing evolutionary development, Lee Berger of the University of the Witwatersrand in Johannesburg and colleagues reported finding 1,550 fossils from a previously unknown species that they call Homo naledi (SN: 10/3/15, p. 6).