Berger was raised in Sylvania and Savannah, Georgia. After he received a B.A. in anthropology from Georgia Southern University in 1989, he studied under noted South African paleoanthropoligist Phillip V. Tobias at the University of the Witwatersrand in Johannesburg. Berger received a Ph.D. in paleoanthropology from the University of the Witwatersrand in 1994 and became a postdoctoral research fellow in the university’s department of anatomy and human biology in 1995. Between 1996 and 1997, Berger served as the director of the university’s paleoanthropology research group in the School of Anatomical Sciences.
He briefly returned to the United States during the late 1990s, accepting adjunct professorships in the anthropology departments of Duke University (1997) and the University of Arkansas (1998). In 1999, however, he became the director of the Palaeoanthropology Unit for Research and Exploration at the Bernard Price Institute of Palaeontology at the University of the Witwatersrand. From 2004 he served as a reader in human evolution and the public understanding of science at the Institute for Human Evolution and the School of Geosciences at the university.
Berger’s early research involved examinations of the morphology of A. africanus. He was part of the team that made the first discovery of A. africanus at the Gladysvale Cave site near Sterkfontein in South Africa. In 1995 he and a colleague published a paper hypothesizing that the “Taung child,” a 2.5-million-year-old fossil of A. africanus previously thought to have been killed by a predatory mammal, may have been killed by a bird of prey. During a vacation with his family in 2006, Berger explored the Ucheliungs Cave in Palau and discovered the bones of a group of small-bodied humans. In his controversial follow-up research, he suggested that many of the skeletal characteristics of the remains were too primitive to occur in genus Homo, whereas other scientists claimed that the remains belonged to a pygmy population of H. sapiens.
In 2008, during a fossil-hunting expedition to the Malapa Caves in the Cradle of Humankind World Heritage site near Johannesburg, Berger’s nine-year-old son, Matthew, discovered a fossilized jawbone and collarbone belonging to a juvenile male hominin; Berger noted the mix of primitive and modern characteristics in one of the specimen’s canine teeth. Shortly thereafter, Berger discovered the partial skeleton of an adult female that possessed similar features. The partial skeleton, labeled MH-2MH2, has become recognized as the most complete early hominin skeleton known. The well-preserved bones found at the site included a pelvis, a foot, a complete right hand, and two skulls.
A closer examination of the remains revealed that they possessed a combination of apelike and humanlike features; the specimens also displayed more features in common with the earliest members of Homo than any other australopithecine species. Berger and colleagues named this new species A. sediba after the word in the Sesotho language meaning “fountain” or “wellspring.” Uranium dating determined that the remains were between 1.78 million and 1.95 million years old, which . When this technique was combined with paleomagnetic dating (the calculation of a rock’s age by comparing the magnetic orientation of the iron within it to that in surrounding rocks), the specimens were determined to be approximately 1.977 million years old. The results raised the possibility that A. sediba may have been an ancestor to H. erectus. Furthermore, the age of the specimens and the collection of features they shared with Homo may either allow A. sediba to become the recognized transitional species that links Australopithecus with Homo or confirm it as a contemporary of the true transitional form.
Berger received the first annual National Geographic Society Prize for Research and Exploration in 1997. He served as the secretary for the Royal Society of South Africa in 1996 and 1997 and was a founding trustee of the Jane Goodall Trust, South Africa. He became a member of the American Association for the Advancement of Science in 2001.