Lucy's Legacy: The Fossil That Revolutionised Our Knowledge of Human Evolution Fifty Years Later

On the morning of November 24, 1974, Donald Johanson and his doctoral student, Tom Grey, arrived at the location in Hadar, Ethiopia, where it was already quite hot. Originally, the two had planned to map the area, but when they were there, they decided to check for fossils. Sadly, at the time, there weren't many fossils visible on the surface, but they were able to locate pieces of gazelles, antelopes, and even a small monkey. Not exactly the luckiest of discoveries for a location believed to contain sediments older than three million years.

The two researchers began to head back to the car when the blazing sun was at its highest point, but they chose to take an alternative path along a gully. Johanson happened to glance over his shoulder at this moment and noticed something. A tiny fragment of bone that looked to be the right proximal ulna (forearm) of an animal, most likely a monkey, was lying on a hill. Johanson saw something strange, though, when he flipped the piece over in his fingers; it seemed to be the property of a hominid.

Johanson and Grey then discovered a fragment of skull bone, a femur, a pelvis, some ribs, and more while surveying the remainder of the hill.

Although these bones were little, Johanson, Grey, and others found several hundred bone fragments at the location now known as Afar Locality 288 during the course of the following few weeks of additional excavation. After meticulously recording each piece's precise location, they returned to camp to conduct additional investigation. After a while, the group had gathered about 40% of one skeleton from an unidentified hominid species.

The significance of this discovery and its implications for our knowledge of human ancestry was unknown to Johanson and Grey at the time, but they knew they had something unique on their hands.

Since her skeleton was discovered on that Ethiopian slope fifty years ago, Lucy has grown to become a legendary character in the history of human evolution. Lucy on a gravelly Hill "Lucy" may not seem like a name you'd give a significant scientific specimen, yet both the name and its origin story are quite memorable.

He and his then-girlfriend, Pamela Alderman, were talking about the possible sex of the enigmatic specimen that night in November 1974 while the excavation crew unwinded in their camp when the Beatles' 1967 hit song Lucy in the Sky with Diamonds started playing on the radio. They chose to call her Lucy since Johanson was certain the bones belonged to a woman.

Although Lucy was the first known specimen of the hominid species Australopithecus afarensis, the precise name of that species was not well-known at the time and is difficult to recall. Johanson told IFLScience, "Once that [name] was said, it stuck." After that, everyone simply began uttering phrases like

Will we return to the Lucy location? Will more of Lucy's skull be discovered, in your opinion? What was Lucy's age when she passed away? etc.

"Therefore, she started to become both a significant scientific finding and a personality." And that's a big part of what Lucy left behind. "[S]he has kind of established herself as the standard... I believe that people recognize this discovery as unique, perhaps more so than [it being merely a skeleton].

Australopithecus afarensis and Lucy

A member of the australopithecine group, which includes early hominins (humans and their close, now-extinct cousins) who inhabited Africa between 4.1 and 1.4 million years ago, is Australopithecus afarensis. Before Lucy's 1974 discovery, paleoanthropologists knew of just Australopithecus africanus, which translates to "southern ape of Africa," was another member of this group that was found in 1924. However, very few fossils had been found at this time, thus nothing was known about these extinct hominids.

However, Lucy's remains' relative completeness offered a hitherto unheard-of insight into the species. Crucially, Lucy's skeleton demonstrated that these early hominids, like contemporary humans, were bipedal, meaning they walked upright on two legs. For example, there are a number of characteristics specific to bipedality in Lucy's distal femur, the lower portion of her thigh bone that forms the upper portion of the knee joint. Lucy was able to balance on each leg because of the shaft's angle with respect to the condyles and the rounded portion of the joint.