By Anne Ryman, The Arizona Republic

TEMPE, Ariz. — The man who found Lucy, the world’s most famous fossil, is never far from her. Just steps from Donald Johanson’s office at Arizona State University is a tiny skeleton made of plastic casts of the 3.2 million-year-old fossil. They’re wired together and propped inside a glass box.

Lucy souvenirs decorate Johanson’s office: an “I Love Lucy” button, a framed Lucy stamp issued in Ethiopia and porcelain Lucy salt-and-pepper shakers.

Single discoveries often define a scientist’s career, but nothing in Johanson’s field was as big as the Lucy find in 1974.

Lucy is the oldest, most complete skeleton of an adult ancestor of humans. A new ancestral species, Australopithecus afarensis, she prompted a controversial overhaul of the evolutionary tree. Scientists since have found older fossils, but none has matched Lucy’s fame.

In four decades, Johanson and colleagues gathered about 370 additional specimens, shedding further light on the species. As director of Arizona State’s Institute of Human Origins, Johanson oversees seven scientists who have generated their own recent headlines. He, though, will forever be identified with Lucy and will always wrestle with the riddles the fossil continues to pose.

Johanson sits in his office beneath replicas of famous cave paintings in Lascaux, France. His resonant voice quickens as he speaks of Lucy as if she were alive, recalling how “we found her.”

The 31-year-old paleoanthropologist had just finished his Ph.D. His team had chosen a remote area in northeastern Ethiopia, known as Hadar, because of the fossils regularly coughed up by the region’s shifting tectonic plates. Rare, heavy rains cut deep gashes into the hills and reveal ancient fossils to the sharp-eyed scientist.

That Sunday, Johanson felt lucky. The son of a widowed immigrant cleaning woman, he had been told by his high-school counselor that he wasn’t smart enough to attend college. He went anyway. And now, on this clear morning, he wrote the words “feel good” in his journal.

Accompanied by a graduate student, Tom Gray, they walked and looked for fossils in the heat of more than 100 degrees.

A brownish-gray object caught Johanson’s eye. The 2 1/2-inch fossil had a curved flare resembling a humanlike elbow. They quickly spotted more fossils: a piece of jaw with a molar, parts of a leg and arm, a shard of skull.

Johanson knew they had made a rare and special find.

They gathered up the pieces of jaw, marked the spot and jumped into a Land Rover for the half-hour trip back to camp.

They stayed up all night, drank beer and celebrated. The Beatles song, Lucy in the Sky With Diamonds, played on a tape recorder.

Johanson’s girlfriend, Pamela, said, “Why don’t you call her Lucy?”

The name took hold.

For three weeks, the team scoured the hillside and gully, uncovering fossil fragments and pieces. Time and the elements had scattered Lucy over an area about the size of a living room. They found no two fossils the same, which reinforced Johanson’s theory that the fossils belonged to one individual.

Johanson spent the next five years intensely studying Lucy. The Ethiopian government agreed to let him borrow the fossils because the country had no sophisticated labs. To get her to the United States, he wrapped her in toilet paper, packed her in a yellow, foam-lined suitcase and carried her aboard a plane.

Lucy moved into a new home at the Cleveland Museum of Natural History, where Johanson worked as a curator. She was kept in a 5-foot safe in his office.

Analyzing Lucy took years. Johanson had to juggle research with his job at Case Western Reserve University, museum duties, other field expeditions and subsequent fossil finds. He enlisted the help of another scientist, Tim White, to help.

The pair would meet late at night in the museum’s lab. Using plaster casts of the fossils, they compared and measured the various features. They argued for months about whether the fossils represented a new species.

In the end, they decided the evidence was convincing. The species had walked upright and had a brain no bigger than a grapefruit. Its hands resembled human hands, with more curled fingers. Its estimated size ranged from 3 and a half feet to 5 feet tall and about 60 pounds to 100 pounds.

Their resulting 1979 paper in the journal Science announcing the new species drew worldwide attention. The paper challenged prevailing evidence that walking upright evolved along with an enlarged brain.

The paper drew harsh criticism from other scientists, including famous paleoanthropologists Mary Leakey and her son, Richard, who accused Johanson of being hasty in his conclusions. Johanson stood his ground.

In 1980, he returned Lucy to the Ethiopian government, knowing he could return to study her. He since has seen Lucy many times and never tires of the reunion, of seeing the 47 pieces that emerged to reshape his life.