Science: The Lucy Link

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An old skeleton, a new name

Lucy was not much more than a meter tall (just under 4 ft.), suffered from arthritis and had a head like an ape. But last week she became a front-page celebrity. Anthropologist Donald Carl Johanson of the Cleveland Museum of Natural History called a press conference to claim that Lucy* is Australopithecus afarensis, a new species in man's evolutionary lineage. He put her age at 3.5 million years, which makes her younger than man's earliest known ancestor, Ramapithecus, who lived 10 million to 14 million years ago. But Johanson said Lucy came before the hominids split into two branches, one leading eventually to Homo sapiens and another leading to the now extinct ape man Australopithecus. The discovery, said Johanson, is "an exciting and provocative breakthrough."

Even before Johanson assembled Lucy's remaining bones, he could see that she had been bipedal: the clue was a telltale knee joint. In addition, Lucy's tiny skull suggested a brain too small to place her among previously discovered toolmaking hominids. At first, Johanson and his partner, Timothy White of the University of California at Berkeley, tentatively classified her as Australopithecus africanus, a species discovered in 1924 by South African Anthropologist Raymond Dart. The team changed its view after locating the bones of 13 creatures roughly similar to Lucy in the Afar region, and comparing them with other hominid fossils found in 1975 by the well-known anthropologist Mary Leakey, in Laetolil, Tanzania. Above all, Lucy's unusual dental and cranial features convinced the pair that she was of a different species.

The implications, says Johanson, are profound. First, the old notion that man became bipedal as his brain grew is certainly false: Lucy was small-brained, but could stand erect. Second, because Lucy is basically so primitive, man may have split from his ape ancestors much later than 15 million years ago, as is commonly supposed. Says Johanson: "Afarensis suggests that anthropologists might reopen the case of a divergence which occurred between 8 and 10 million years ago."

Johanson's announcement, however, left most colleagues puzzled. The bones have been around for more than four years now, long since dated by potassium-argon tests, and many anthropologists who have studied them are generally convinced that Lucy is an Australopithecus africanus, not some new species.

Also, the notion that man became bipedal in tandem with his brain growth is no longer widely held. (More likely, changing survival needs led him out of the jungle to the African savanna, where he stood to peer over tall grasses.) As for Johanson's announcing a "new" name for Lucy, some specialists observe he did that a year ago in a little-noticed Cleveland Museum journal. "I don't think Johanson has made a particularly good case for her being a different species," says a leading anthropologist, and adds: "He's a guy who's always trying to upstage people."

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