She was classified as one of the most significant scientific discoveries of the 20th century: a small woman, slightly more than one meter tall, who lived in east Africa and died at 30, more than 3 million years ago.
For more than three decades, Lucy and her kind were considered the ancient forbears of the human race, among the first to walk upright. But Tel Aviv University researchers revealed in a journal article published yesterday that Australopithecus afarensis, which walked nearly upright but had a brain resembling that of a chimpanzee, was nothing but a cousin of those forbears and belongs to a different branch of the human family - one that became extinct millions of years ago.
The findings mean that researchers now recognize an evolutionary gap of more than 1 million years during which no fossils have been found that could be considered the ancient ancestors of humankind.
The findings of the research team, led by Prof. Yoel Rak, require a return to the drawing board for a new tree to describe the roots of the human family.
"Lucy was an icon, she was famous as the ancient mother of the human race," said Rak, whose team's research was published on the cover of the American journal Proceedings of the National Academy of Sciences. "But it turns out that's not so."
Rak and other researchers arrived at their conclusion by conducting an anatomic analysis of a skull of the same species as Lucy and comparing the findings with 146 other skulls of hominids and monkeys. He discovered that, in contrast to the prevailing view, the afarensis belongs to a family that does not have a direct link to homo sapiens.
Dozens of skulls peer out from the walls of Rak's office. Some look human, while others appear to more closely resemble monkeys, but all those hominids became extinct a minimum of tens of thousands of years ago.
Rak, who teaches anatomy and evolution, is one of the most important researchers in the world when it comes to the evolutionary development of mankind. He based his latest findings on an analysis of another skull of the same type as Lucy's, which his team found in Afar, in Ethiopia, four years ago.
"One of our assistants found the new skull," said Rak. "He identified a tooth rolling around on the slope. In accordance with the method by which we work, he fired in the air and we all ran over to see. And truly, we discovered there many elements of the skull. We sifted through almost the entire mountain and brought everything to a museum in Addis Ababa. Today these findings are considered state treasures, and the Ethiopians, rightly, don't allow them to be removed. We sat in the museum and spent months cleaning, attaching and reconstructing. That's how we got an almost perfect skull of Australopithecus afarensis, the species that Lucy belonged to."