Findings redefine human evolution

Ben Wolford

KSU professor: Apes evolved from humans

Check out a graphic that explains Ardi’s structure.

Much of what we thought we knew about human evolution is wrong.

That’s what research from Kent State professor C. Owen Lovejoy and a team of scientists suggests. The 11 articles of analysis – including five authored by Lovejoy – appear in a special edition of Science Magazine today.

“His research findings clearly redefine our understanding of human evolution,” said John West, Kent State’s vice president for research.

And it has made national and international headlines, with Lovejoy’s name appearing on news Web sites in Mexico, Brazil and Turkey.

“I got calls from the BBC in London and CNN who want him on their morning show,” Kent State spokeswoman Emily Vincent said.

After discovering a skeleton of Ardipithecus ramidus in 1994, a team of more than 40 scientists, including Lovejoy, spent 15 years analyzing the fossils. Today they release their findings.

“Darwin argued that the canine reduced because we took up tools and that the brain got big because we began to use tools, and that was his algorithm for human evolution,” Lovejoy said in a video interview published by Kent State. “It’s completely wrong, but it’s only wrong because of what we know today.”

The skeleton, nicknamed “Ardi,” is the oldest, most complete hominid fossil ever discovered. It predates “Lucy” – the Australopithecus afarensis that gave Lovejoy previous acclaim when he reconstructed her skeleton – by more than a million years.

“Everybody in the world up to now has thought that we evolved from something that was generally chimpanzee-like,” Lovejoy said. “It turns out that chimpanzees have evolved from something that’s more human-like.”

Essentially, Ardi discounts the thought that a missing link, a transitional figure between humans and modern chimpanzees and gorillas, will be discovered. Ardi’s human characteristics suggest a novel picture of the last common ancestor of great apes.

Lovejoy participated in a press conference announcing his team’s long-withheld findings yesterday morning in Washington, D.C.

One of the more illuminating discoveries is Ardi’s method of locomotion.

“Ardi lived in a cooler, deep forest environment,” said Richard Meindl, chair of Kent State’s anthropology department. “Why is it interesting? Because we used to think human ancestors developed the ability to walk – the modern way – in open grassland, like a savanna. This individual was living in a deep forest.”

Ardi could climb through trees on all fours with an opposable big toe like a chimpanzee’s. But on the ground, she walked on two legs.

When scientists found Ardi’s skeleton, it was in poor condition, trampled and scattered by 4.4 million years of existence.

“It took us about three or four years just to clean the specimen because the bones were so soft,” Lovejoy said.

In her lifetime, Meindl said, Ardi would have stood 4 feet tall and weighed 120 pounds. She was discovered 40 miles from the site where Lucy was found in Ethiopia.

Lovejoy is one of the most prolific and notable researchers at Kent State and was admitted as a member of the National Academy of Sciences in 2007. Lovejoy teaches Biology of Ardipithecus this semester, a graduate-level course.

West said Lovejoy kept his research’s revelations even from him.

“There’s been kind of an embargo within the group on talking about that,” West said. “He hinted that there was something coming but never the details of it.”

Not only do Lovejoy’s contributions to the team’s research add to the prestige of Kent State’s research arm, West said this work gets to the heart of human curiosity.

“All of us are interested in what our origins are,” West said. “And certainly evolution is a key topic for investigation. The fact that we’ve pushed back two million years the understanding of the origins of human evolution has a significant impact on our understanding of the world around us.”

Contact news team leader Ben Wolford at [email protected].

College of Arts and Sciences reporter Mariana Silva contributed to this report.