Who Is Lucy The Australopithecus, And Why Is She So Important To The Study Of Human Ancestry?

If you were one of the millions of people to use Google’s search engine yesterday, November 24, you would have seen the Google Doodle animation depicting a small, hairy, chimp-like creature, walking upright between a chimpanzee and a human — Google’s play on the famous March of Progress picture. The chimp-like creature with human features spotlighted in the doodle is Lucy the Australopithecus, a world-famous human ancestor discovered on November 24, 1974. But who is Lucy the Australopithecus, and what makes her so important to the study of our own human ancestry?


Many things make Lucy one of the most significant discoveries ever made. For starters, Lucy was the most complete Australopithecus skeleton ever found. In the 1970s, a “surge of discoveries” of human ancestor bones were being made, according to Time. However, the majority of them weren’t much more than bone fragments, which helped scientists at the time to piece together bits of our ancestry, but they were never able to get a clear picture of where we came from. Lucy’s discovery changed all that, as her skeleton was 40 percent complete — more than any other Australopithecus previously discovered.

“Unlike most other fossils of early man—a tooth here, a bone fragment there, occasionally a portion of a skull—this one comprised a good part of the skeleton.”

Lucy was also discovered to be a wholly new species of Australopithecus — Australopithecus afarensis. Most significant about Lucy was that although the size of her brain was only one-third that of modern man, she was found to be bipedal. This meant scientists who had previously believed that bipedalism occurred as the brain grew had to rethink everything they thought they knew about our ancestry. Donald Carl Johnson, one of the researchers who originally discovered Lucy, says that because carbon dating showed Lucy to be roughly 3.2 million-years-old, that means that she was around before hominids split into two branches — the one that led to us, and the one that led to their extinction.

“First, the old notion that man became bipedal as his brain grew is certainly false: Lucy was small-brained, but could stand erect. Second, because Lucy is basically so primitive, man may have split from his ape ancestors much later than 15 million years ago, as is commonly supposed.”

According to Smithsonian.com, Lucy shared characteristics that belonged to both humans and apes — she had long arms relative to the size of her legs, was covered in hair, and had a distended belly like a chimp, but she was also found to have used basic stone tools like our later ancestors did. Her discovery led scientists to originally believe that Lucy was the oldest direct ancestor to humans, after her species “diverged from chimpanzees about 4 million years ago.” Though recent discoveries tell us that we likely actually split from chimps around 13 million years ago, Lucy’s discovery has brought researchers one step closer to learning exactly how we evolved into modern humans.

Who Is Lucy The Australopithecus, And Why Is She So Important To The Study Of Human Ancestry? The nearly half-complete skeleton of Lucy the Australopithecus [Photo by Dave Einsel/Getty Images]With the discovery that Lucy used stone tools came the realization that Australopithecus afarensis were the first species in our evolutionary ladder to cook, cut, and eat meat, says Shannon McPherron, an archaeologist at the Max Planck Institute for Evolutionary Anthropology.

“We can now picture Lucy walking around the east African landscape with a stone tool in her hand scavenging and butchering meat. With stone tools in hand to quickly pull off flesh and break open bones, animal carcases would have become a more attractive source of food.”

Lucy, and all of her kind, may look more like modern man than other Australopithecus species, but she differs in one significant way: Lucy was actually very small. When she died, Lucy was a fully developed, albeit young, adult, but though she was bipedal like modern man, she stood just 3.7 feet tall, and weighed a measly 64 pounds.

She may have been quite tiny, but the discovery of Lucy the Australopithecus 41 years ago has led to a bigger understanding of our ancestry than any other finding before her.

[Photo by Dave Einsel/Getty Images]