Radiometric dating technique used to date lucy

29 Aug

The paleoanthropologist—then a professor at Case Western Reserve University in Cleveland—was several weeks into his third expedition to Hadar, Ethiopia, a site that had proven to be a treasure trove of early fossil remains.His international field team had already found leg bones and several jaws that were among the oldest examples of hominids—the family of bipedal primates that includes humans and their ancestors—and Johanson was convinced that an even bigger discovery was in the offing.In this regard, Lucy was like nothing the researchers had ever seen.Anthropologists had often speculated that erect posture had developed as hominids evolved larger brains, but Lucy’s brain was only the size of a grapefruit—roughly as big as a chimpanzee’s.When he and Gray bent down to examine it, they saw that it rested next to other pieces of thighbone, vertebrae and ribs. “We were just astounded,” Johanson later told the New York Times.“You just don’t expect to find this much of a single individual.” Johanson and Gray raced to tell their colleagues. ” That night, the jubilant field team celebrated the discovery over dinner and several cans of beer.Many held that Australopithecus afarensis was not a discrete species, and still others—most notably the Kenyan paleoanthropologist Richard Leakey—balked at the assertion that fossils like Lucy were the direct ancestors of modern humans.The case for Australopithecus afarensis was strengthened in the early 1990s, however, when further research at Hadar yielded a wealth of other Lucy-like fossils including near-complete skulls of both male and female specimens.

Her larger pelvic opening suggested she was female, and wear on her wisdom teeth hinted she was probably around 20 years old when she died (more recent estimates suggest she may have been closer to 12 or 13).A more ancient or complete specimen had never been discovered.When pieced together, the small bits of brown bone painted a stunning picture of what Lucy would have looked like.As they drove up to their camp, Gray laid on the horn and yelled out, “We’ve got it! In the background, a stereo blared with The Beatles’ album “Sgt. When the song “Lucy in the Sky with Diamonds” came on, someone suggested calling the new skeleton “Lucy.” The name stuck.Along with the expedition’s co-director, the French geologist Maurice Taieb, Johanson and the rest of the field team spent the next several days scouring the Lucy discovery site.