6TH GRADE SOCIAL STUDIESNOV. 5, 2015 The ‘Lucy’ fossil rewrote the story of humanity Forty years ago in east Africa, a team of scientists found a fossil that changed our understanding of human evolution “Might Lucy be our By Melissa Hogenboom direct ancestor, a missing 27 November 2014 gap in the human family tree?”

Taung child

Forty years ago, on a Sunday momentous find, because the morning in late November 1974, a sediments at the site were known team of scientists were digging in to be 3.2 million years old. "I an isolated spot in the Afar region realised this was part of a skeleton of Ethiopia. that was older than three million Surveying the area, years," says Johanson. It was the paleoanthropologist Donald most ancient early human – or Johanson spotted a small part of hominin – ever found. Later it an elbow bone. He immediately became apparent that it was also recognised it as coming from a the most complete: fully 40% of human ancestor. And there was the skeleton had been preserved. plenty more. "As I looked up the At the group's campsite that slopes to my left I saw bits of the night, Johanson played a Beatles Lucy skull, a chunk of jaw, a couple of cassette that he had brought with vertebrae," says Johanson. him, and the song "Lucy in the Sky It was immediately obvious with Diamonds" came on. By this that the skeleton was a time Johanson thought the PAGE 1 6TH GRADE SOCIAL STUDIESNOV. 5, 2015

the the prominent anatomist Sir Arthur Keith as just an skeleton ape and of no major importance. was female, Over the next 25 years, more evidence emerged because it and showed that Dart had been right all along. By was small. the time Lucy came along, anthropologists accepted So someone that australopithecines were early humans, not just said to him: apes. So upon her discovery, Lucy became the oldest "why don't potential ancestor for every known hominin species. A replica of Lucy’s skull you call it The immediate question was: what was she like? Lucy?" The name stuck immediately. "All of a sudden," says Johanson, "she became a person." Lucy had an "incredible amalgam of more primitive and more derived features that had not It would be another four years before Lucy was been seen before," says Johanson. Her skull, jaws officially described. She belonged to a new species and teeth were more ape-like than those of other calledAustralopithecus afarensis, and it was clear Australopithecus. Her braincase was also very small, that she was one of the most important fossils ever no bigger than that of a chimp. She had a hefty jaw, discovered. a low forehead and long dangly arms. But at the campsite the morning after the For Johanson, in the field at Hadar, it was discovery, the discussion was dominated by immediately apparent that Lucy walked upright, like questions. How old was Lucy when she died? Did the Taung Child. That's because the shape and she have children? What was she like? And might positioning of her pelvis reflected a fully upright she be our direct ancestor, a missing gap in the gait. Lucy's knee and ankle were also preserved and human family tree? Forty years later, we are starting seem to reflect bipedal walking. Later studies of A. to have answers to some of these questions. afarensis feet offer even more evidence. Though she was a new species, Lucy was not When she was discovered, Lucy was hailed as the firstAustralopithecus found. That was the Taung the oldest direct ancestor of modern humans. "A. Child, the fossilised skull of a young child who lived afarensis took us one small step closer to that about 2.8 million years ago in Taung, South Africa. common ancestor we share with chimpanzees," says The Taung Child was discovered in 1924 and was Tim White of the University of California, Berkeley. studied by anatomist Raymond Dart. He realised "We knew we were genetically incredibly close to that it belonged to a new species, which he called chimpanzees, with the last common ancestor we Australopithecus africanus. shared with them estimated to be around six million Dart wrote: "I knew at a glance that what lay in years ago. Lucy had closed a gap in our knowledge." my hands was no ordinary anthropoidal brain. Here It now looks like Lucy did not take us as close in lime-consolidated sand was the replica of a brain to our common ancestor with chimps as everyone three times as large as that of a baboon and thought. The latest genetic studies suggest we considerably bigger than that of an adult actually split from chimpanzees much earlier, chimpanzee…" The Taung Child's teeth were more perhaps as much as 13 million years ago. If that is like a human child's than an ape's. Dart also true, the 3-million-year-old Lucy arrived quite late in concluded that it could walk upright, like humans, the story of human evolution. Older fossils, such as because the part of the skull where the spinal cord the 4.4-million-year-old Ardipithecus described by meets the brain was human-like. White and his colleagues, are closer to our ape The Taung Child was the first hint that humans ancestors. originated from Africa. But when Dart published his analysis the following year, he came in for stiff criticism. At the time, Europe and Asia was thought to be the crucial hub for human evolution, and scientists did not accept that Africa was an important site. The Taung Child was denounced by

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