In 1974, former Cleveland Natural History Museum curator Donald Johanson brought a suitcase full of bones from Ethiopia to Cleveland and one of the first people he contacted to study the remains was newly-minted Ph.D researcher Owen Lovejoy.
Lovejoy, 50 years later, recalls his first impression of seeing the fossils.
"I was stunned by the fact that they were so perfectly preserved," he said. "It's over 3 million years old and it's almost perfectly preserved right there in the bone."
Lovejoy right away recognized that this creature walked upright.
The question that intrigued him was, why? Why did human ancestors descend from the trees to walk on two legs?
Lovejoy said there are several clues:
"Humans are omnivores," he said, "and searching for food becomes a wide ranging activity. And if you find it, what are you going to do with it?"
He said an upright stance allowed our distant ancestors to carry food back to the group.
He said the implications of that innovation in our evolution were profound.
Our early ancestors, like Lucy (Australopithecus afarensis),lived in a social group, "in which the males and females pair bonded with one another and formed family units."
Lovejoy said recent research on the human brain shows that we were wired early on to form social bonds stronger than any of our primate relatives.
"And as a consequence, human ancestors were capable of achieving all sorts of successful adaptations because they cooperated and because they had a special, reproductive system that was built out of a whole set of pair bonds and family structures," according to Lovejoy.
"If you look at other primates, the males are virtually uninvolved in any aspect of the reproductive process except for competing to get access to the females. So when you have a parenting pair, you have twice the reproductive energy of a typical primate. And that's another reason why we were so successful. We put twice as much energy into reproduction as any other primate does."
Guests:
-Jeff St. Clair, Midday Host, Ideastream Public Media
-Owen Lovejoy, Ph.D., Professor of Anthropology, Kent State University
