WASHINGTON (AP).- An analysis of 2 million-year-old bones found in South Africa offers the most powerful case so far in identifying the transitional figure that came before modern humans — findings some are calling a potential game-changer in understanding evolution. The bones are from Australopithecus sediba. The research places that pre-human branch of the evolutionary tree as the best candidate to be the ancestor of the human line, said Lee R. Berger of the University of Witwatersrand in South Africa. The bones, found in 2008 in the fossil-rich cave region of Malapa near Johannesburg, show a head-to-foot combination of features of Australopithecus and the human genus, Homo. “It’s as if evolution is caught in one vital moment, a stop-action snapshot of evolution in