Unlike in most mystery novels, a murder wasn’t incriminated after Lucy’s bones were found.
Archaeologists discovered one of the most famous examples of our early ancestors the Australopithecus afarensis, dubbed Lucy, in Hadar, Ethiopia. The story goes like this: in 1974, the archaeologist Donald Johanson spotted something poking out of the sand in a gully that had already been excavated. Upon further inspection, the Johanson and his team immediately realized that the there were human-like bones on the site - and more than just one. 162 bones later, listening to the Beatles song “Lucy in the Sky with Diamonds” on repeat, they dubbed the skeleton they found Lucy.
Lucy and her kin Australopithecus afarensis lived between two and four million years ago. 200,000 years ago, the first Homo sapiens walked the earth. In less than two million years, our entire genus, Homo, expanded all over the world. How did Australopithecus afarensis like Lucy become iPhone-wielding, test-taking students?
The short answer: evolution. The Australopithecus afarensis species was believed to be the direct ancestors of Homo habilis, believed to be the first in the Homo genus. Directly tracing down the Homo Habilis evolutionary line eventually led archaeologists to Homo neanderthalensis, commonly known as the Neanderthals, and Homo sapiens: humans. This genealogy, however, is now put under doubt: recent discoveries may suggest that we aren’t direct descendants of Lucy at all.
In 2013, an excavation crew in South Africa scraped through a 10 in. high tunnel known as Spiderman’s Crawl and clambered down a 40 ft. drop known as the Dragon’s Back to reach the Dinaledi, or Star, Chamber. In the Rising Star Chamber, these archaeologists identified at least 15 separate specimens, excavating over 1,200 bones.. The specimens were different than other human species that had been discovered: the legs and feet were long like those of a human; the skull was human-like as well, but smaller than a modern human’s; the pelvis was primitive like Lucy’s. The latest addition to our long list of ancestors - Homo Naledi.
Archaeologists have not yet radiocarbon dated the specimens since the process could damage the bones. Expert estimates, however, suggest the Homo Naledi might fit into the evolutionary timeline around 2.5 million years ago. In fact, Homo Naledi may be the bridge between the genus Homo, which we belong to, and the genus Australopithecus, which Lucy belonged to. But since Homo Naledi and Lucy lived at the same time, Australopithecus afarensis like Lucy would most likely be a cousin to Homo Naledi rather than an ancestor. Archaeologists can no longer draw a straight line down from the Australopithecus genus to the Homo genus. Then, is the Australopithecus genus just a dead end? How did the Australopithecus genus die out? Why?