Johanson came from modest beginnings. His parents, Carl Torstgen Johanson and Salia Eugenia Johanson, were immigrants from Sweden. His father, a barber, died when Johanson was two years of age. Some time later, mother and son moved to Hartford, Connecticut, where she worked as a servant. A neighbor in Hartford taught anthropology, and he sparked the boy's interest in the subject. In high school, Johanson became interested in paleoanthropology, the study of fossils of human ancestors when he read about Louis and Mary Leakey's finds in Tanzania. In 1959, the Leakeys used the potassium-argon dating method to determine that their fossil skull of a hominid, Australopithecus boisei, was 1.8 million years old. Hominids are members of the human family. In 1962, they discovered Homo habilis, a true human fossil of about the same age. Johanson entered the University of Illinois as a chemistry major, but he changed to anthropology. In 1966, he...