After 50 years, Lucy faces rivals with other human ancestors

In 1974, paleoanthropologist Don Johanson and student Tom Gray unearthed a 40% complete skeleton of an early human ancestor, fundamentally changing the human family tree. The specimen acquired a nickname that persisted: Lucy, after the Beatles song playing at the fossil hunter’s camp--“Lucy in the Sky with Diamonds.” At 3.2 million years old, some thought her species, Australopithecus afarensis, was close to when the ancestor of humans had split from the ancestor of chimpanzees