By Bruce Bower
MINNEAPOLIS — Fossils described last year as representatives of an ancient species critical to human evolution have reentered the scientific spotlight and set off a new round of debate over the finds’ true identity.
Researchers described analyses of new and previously recovered remains of a South African species called Australopithecus sediba on April 16 at a meeting of the American Association of Physical Anthropologists. Evidence is accumulating, they reported, that 2-million-year-old A. sediba formed an evolutionary connection between relatively apelike members of Australopithecus and the Homo genus, which includes living people.
It’s now clear that A. sediba shares more skeletal features with early Homo specimens than any other known Australopithecus species does, said Darryl de Ruiter of Texas A&M University in College Station. “We think A. sediba is a possible candidate ancestor for the genus Homo.”
De Ruiter suspects that an isolated population of the hominid species Australopithecus africanus gradually evolved into A. sediba, resulting in a species characterized by an unusual mix of skeletal traits, some typical of Australopithecus in general and others of early Homo.