About 50 years ago, Donald Johanson’s life changed in the blink of an eye.
"My life certainly was BL — you know, “before Lucy” — and AL, “after Lucy,'" said Johanson, Ph.D.
The BL period of Johanson’s life ended in 1974. Back then, Johanson was a 31-year-old anthropology professor, doing field research in Ethiopia with a group of grad students. And one day — Nov. 24, to be exact — he and his team were hanging out at their campsite, listening to the Beatles, getting ready for the day’s research expedition. They’d been out there for a while at this point, and so far, the trip had turned up some interesting animal fossils, but no major discoveries. So that day, Johanson decided to check out a new part of the field site.
"I always leave with an optimistic outlook when I begin searching for fossils. And it was a place I had not visited before," Johanson said.
After a long day of investigation, they still hadn’t found much, and Johanson was about ready to head back to camp.
"And as we were leaving, we just went through this little channel where we hadn’t walked earlier," he said.
As they passed through the channel, Johanson happened to glance over his right shoulder.
"And I always scan the landscape around me as I’m walking, and looked down, and saw a little wrench-shaped bone, it was just about 2 inches long, and it was obviously from the elbow," he said. "And I thought, well, it’s so small, it’s probably from a baboon or something like that. But when I picked it up and looked at the anatomy of it, I could see that the anatomy was from a human ancestor, and not a monkey."
Johanson couldn’t believe it — a human fossil. This was the moment he’d been waiting for.
"And I looked up the slope, and saw other bones eroding out of a sandstone. So I saw a bit of an arm and a bit of a leg, and that led to a pelvis, and it ultimately led to 40% of a single skeleton that was 3.2 million years old," he said.
Prior to this moment, Johanson felt lucky if he happened to find a single fragment of a jaw or the remains of a knee joint. But almost half the remains of an individual skeleton, in one place? This was practically unheard of. Johanson and his team brought the fossils back to camp and organized them into an approximation of their original structure. When they stepped back from the table, they found themselves looking at the vague outline of an ancient human ancestor. And they decided to give her a name.
"Lucy, after 'Lucy in the Sky With Diamonds,'" he said.
And so began the AL chapter of Johanson’s career.
"Well, I certainly knew that it was such a unique discovery that it was really gonna change my life in many ways. Because of the science that would come out of it, but also, as I thought about it, my role as a communicator — a public communicator about the science of human origins."
Before long, Lucy — and Johanson — were a sensation.
"I was always overwhelmed that the lecture hall was completely full. People had a real thirst for understanding their origins," he said.
Johanson realized Lucy was an unprecedented opportunity to help quench that thirst.
"When you have a piece of jaw or a vertebra, it’s very difficult to really connect with something that’s given a number like KNMER1560 or something," he said.
It’s one thing to try to grasp the concept of a human ancestor that’s over 3 million years old. So instead, Johanson just tried to focus on introducing people to Lucy.
"People would say, 'If we saw Lucy, what would she look like?' And I’d say, 'Well, one thing is we’d see her walking up right, which is very rare,'" he said. "But as she got closer to us, one would see that she had a very small skull, which meant she had a relatively small brain case, the size of which was about a cup and a half of coffee. Ours is about six cups of coffee. We would see her face a very projecting muzzle. And we would see a creature that had fairly long arms that reach farther down towards the knees than ours do. They could visualize that as a person, as an individual."
That brain case was a big deal. Prior to Lucy, the prevailing theory about human evolution was that we started walking on two legs because our brains were developing faster than our bodies. Lucy threw that idea out the window. But Johanson said the cultural fascination with Lucy was deeper than pure science.
"It’s one of the fundamental questions that we all ask ourselves, and maybe all ask our parents. You know, 'Where do I come from?'"
It’s a question Johanson never got the chance to ask his own father.
"As a young boy, my biological father passed when I was only 2 years old, so I never knew him, but in the neighborhood where I was living there was an anthropologist," Johanson said.
This friendly neighborhood anthropologist was named Paul Leser. Johanson was the kind of kid who ran around the neighborhood picking up lizards and catching butterflies. And Leser sensed that Johanson’s curiosity needed some encouragement.
"And the greatest gift that he gave me was access to his library. I was always interested in the natural world. And he showed me a book when I was 13 years old called “Man’s Place in Nature,” that was written way back in the 1800s by Thomas Henry Huxley. And I read that book in one evening, it was so interesting. Because it suggested that humans and apes had a common ancestor. And that the oldest ancestors of humans would be discovered in Africa. And that was an epiphany for me. That was when the spark went off."
Back then, Johanson says, many in the scientific community thought that our closest human ancestors came from Europe. But that chance encounter with Leser and his dog set Johanson on a path that led to a remote valley in Ethiopia. And now, scientists have a definitive answer to that age-old question about where we come from.
"As the evidence has rolled in over all these years, it’s quite clear that all the branches on the human family tree lead back to Africa. We are all Africans, we are all descended from people who evolved in Africa and migrated out of Africa," Johanson said.
Not long ago, Johanson got the chance to revisit the site where he first saw Lucy. And when I asked him what that was like, he said it gave him goosebumps. "50 years ago as I walked by that spot, if I had looked to my left instead of my right, I might never have found Lucy."
As he approaches the golden anniversary of his discovery, Johanson has been reflecting on the role of good fortune in his evolution from a kid chasing butterflies to one of the most significant public communicators in his field. And it’s got him thinking about what Lucy can still teach us about our evolution as a species. Now that we understand so much more about our past, Johanson wants us to ask ourselves another fundamental question: What do we want our future to look like?
"I look back on our ancestors, and of course, the time when Lucy’s species was living. They lived in a world that was very intertwined with the natural world. We think of ourselves as being very separate. And with that perception, we tend forget how impactful we are on the natural world. And if we’re going to continue to exploit the natural world and damage the natural world … our future is going to be in peril," Johanson said.
These days, Johanson is mostly focused on his work as the founding director of the Institute of Human Origins at Arizona State University. But back when he was still teaching, he says part of his job was to remind his students that the scientific and the existential are also intertwined.
"It’s not a straight line from ape to angel, I told my students, when I was teaching in the classroom, how fortunate we are to be who we are. We’ve had a common origin, a common beginning in Africa. I think that we have, in many ways we have a common destiny," Johanson said.