Disinherited Ancestor: Lucy’s kind may occupy evolutionary side branch
By Bruce Bower
About 30 years ago, African excavations yielded the 3.2-million-year-old partial skeleton that became known as Lucy. The find, along with other fossils unearthed soon after, belongs to the species Australopithecus afarensis. Many scientists regard these creatures as ancestors of both the lineage that led to modern humans and of another, now-extinct evolutionary lineage known as robust australopithecines.
However, an analysis of an A. afarensis jaw from a skull discovered in 2002 near Lucy’s site in Ethiopia supports a longstanding minority viewpoint that Lucy’s kind occupied only a side branch of human evolution. A. afarensis evolved into the relatively small-brained, large-jawed robust australopithecines but didn’t contribute to the evolution of modern people, says anthropologist Yoel Rak of Tel Aviv University.