skully

Nearly 2 million years ago, an adult and a child walking through the South African landscape somehow fell through openings in a partly eroded, underground cave and died. Today, that fatal plunge has led to their identification as representatives of a new hominid species — and a contentious debate among paleoanthropologists over the pair’s evolutionary relationship to modern humans. In the April 9 //Science//, anthropologist Lee Berger of the University of the Witwatersrand in Johannesburg and his colleagues assign newly discovered fossils from these ancient individuals to the species //Australopithecus sediba//. They propose that the species served as an evolutionary bridge from apelike members of //Australopithecus// to the //Homo// genus, which includes living people. In a local African tongue, //sediba// means fountain or wellspring, a reference to this species as a candidate ancestor of the //Homo// line. “//Australopithecus sediba// could be a Rosetta Stone for anatomically defining the //Homo// genus,” Berger says. Despite the importance of finding hominid fossils from the poorly understood period between 2 million and 1.7 million years ago, paleoanthropologists familiar with the finds doubt that they will illuminate //Homo// origins. “There’s no compelling evidence that this newly proposed species was ancestral to //Homo//,” remarks Bernard Wood of George Washington University in Washington, D.C.