Donald C. Johanson

1943-

American Paleoanthropologist

Donald Johanson, born June 28, 1943, is an American paleoanthropologist specializing in the study of human evolution. His discovery in 1974 of the fossil skeleton Lucy dramatically changed our understanding of how human beings may have evolved. He has dedicated the last 25 years to looking for clues to questions that have puzzled scientists since Charles Darwin (1809-1882): What made us human? When and why did we begin to walk upright? Why did we develop such intellectual prowess? By approaching these questions from a variety of directions, incorporating techniques borrowed from molecular biology, archeological excavation, and sociobiological studies of primates and hunter-gatherer societies, Johanson has provided new insight into our human origins.

Johanson was born in Chicago, Illinois, the son of Swedish immigrants. His father died when he was two years old, and his mother moved to Hartford, Connecticut. He developed an early interest in anthropology from a neighbor who taught at a nearby seminary. When he was in high school, he was told by his guidance counselor to forget going to college because of poor scores on the Scholastic Aptitude Test. Deciding not to be discouraged, he applied and was accepted at Illinois State University.

Johanson initially studied chemistry but switched over to anthropology and decided to specialize in the study of human origins. He completed his Ph.D. with a comprehensive study on chimpanzee dentition in 1966. He later taught anthropology at Case Western University, Kent State University, Stanford, and the Cleveland Museum of Natural History, but his reputation is based on his fieldwork in Africa.

In 1973 Johanson began to search for fossil remains of hominids, the primitive ancestors of modern humans in the Great Rift Valley in Africa. Exposed sedimentary layers, often millions of years old, contain buried and fossilized animal remains, including those of our direct ancestors. In 1974 in the Afar region of Ethiopia, he found the fossilized remains of a 3 million-year-old female skeleton, named Lucy by field crew. The following year Johanson's crew discovered the fossilized remains of 13 individuals believed to be the oldest evidence of human ancestors living in-groups. In 1986 at Olduvi Gorge, a 1.8 million-year-old partial skeleton was found that was believed to be the first tool maker.

As we travel back in time, our ancestors look less and less like us and begin to resemble our closest ancestor, the African apes. The previously accepted explanation of human evolution suggested that a line of primates with larger brains had evolved, became capable of making tools, and began walking upright to free up their hands. However, it appeared that Lucy and other hominids found at the site were walking upright, although their brains were only slightly larger than the chimpanzee. No stone tools were found at the site, so it may be inferred that our ancestors walked upright for another reason.

Scientists studying human origins had long attempted to find a missing link, the shared ancestor between human beings and apes. After years of studying the fossil remains found at the Hadar site, Johanson in 1978 shocked the scientific community with the assertion that the remains belonged to a species that could indeed be a missing link between humans and apes. He named this new species Australopithecus afarensis. In 1990 Johanson returned to Africa and discovered a large portion of another A. afarensis skull. The reconstruction of the skull convinced most of his critics that the species is the ancestor of both Australopithecus africanus and modern humans, Homo sapiens.

Director of the Institute of Human Origins at Arizona State University, Donald Johanson continues his work in researching human evolution. In 1978 his ideas on the origins of humankind were presented at a Nobel symposium on human origins in Sweden.

LESLIE HUTCHINSON