If you go to Google’s search engine today, you’ll find a short animation of a short, brown, ape-like figure walking in between a chimp and a human. This litlle creature is among the greatest discoveries ever made in the study of our ancestry: Lucy the Australopithecus.
41 years ago today, scientists dug up a skeleton in Ethiopia unlike anything they had ever seen before. A member of the Australopithecus afarensis family, the 3.2 million-year-old fossil belonged to an animal that shared characteristics belonging to both apes and humans. She even appeared to have walked on two legs.
At the time, scientists believed that Lucy was humanity’s oldest direct ancestor after her species diverged from chimpanzees about 4 million years ago. While more recent research has shown that we probably split from chimps around 13 million years ago, Lucy’s discovery brought scientists closer to understanding how our species evolved, Doug Bolton writes for The Independent.
Scientists have known for a while that our genus, Homo, which includes our species as well as our cousins Homo habilis, Denisovans, and the recently-discovered Homo naledi, all evolved from Australopithecus ancestors. However, it’s unclear which Australopithecus species were our direct forerunners.
Though scientists do know that Lucy’s species is out of the running for that position, it’s still possible that they were some kind of distant cousin, Bolton writes.
Lucy’s discovery was incredibly lucky: Most fossils as old as hers are shattered beyond repair. But almost 40 percent of Lucy’s skeleton was found intact, including parts of her spine, which allowed scientists to deduce that her species walked on two legs, James Titcomb reports for The Telegraph.
Based on the fossil’s pelvis, they discovered that it had belonged to a female, who they dubbed “Lucy” after the song playing back at their camp: The Beatles’ “Lucy in the Sky with Diamonds.”
Lucy may not be the ancestral “missing link” in our evolutionary lineage, but the discovery was still suprising. At the time, scientists believed that bipedalism came out of having a larger, more developed brain, Titcomb writes. And despite having a brain about the same size as a chimp's, she could walk on two legs. Also, while she had long arms, lots of hair and a distended belly like a chimp’s, Lucy’s species probably also used basic stone tools at least 1 million years before scientists thought.
"We can now picture Lucy walking around the east African landscape with a stone tool in her hand scavenging and butchering meat," Shannon McPherron, an archeologist at the Max Planck Institute for Evolutionary Anthropology, tells Titcomb. "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."
These days, Lucy’s bones are on display at Ethiopia’s National Museum in Addis Ababa. But for today, at least, Google users around the world can see the digital nod to our ancient cousin.