Rob Blumenschine

PROFILE

“This is a golden opportunity to work in the best place there is in the world to study the origin of the genus Homo,” said Professor Rob Blumenschine of his work at Olduvai Gorge in northern Tanzania. Olduvai, made famous in the 1960s by the discoveries of Louis and Mary Leakey, is the stage upon which some of the earliest human dramas played out. 

In 1987, the torch passed to Blumenschine with his invitation to resume the search for human origins at the gorge. This portion of East Africa’s Rift Valley has been the focus of his fieldwork ever since. Olduvai’s walls have provided paleoanthropologists, past and present, with excellent stratigraphy – layer upon layer of fossil-bearing rock, sand, and soil, interlaced with geochemically datable volcanic ash.

According to Blumenschine, these strata present a rich archaeological record with traces of hominid activities in the forms of the flaked stone tools and butchery-marked bone. He said that Olduvai provides evidence for the first time in human evolution of a whole complex of adaptations which together defines what human beings are fundamentally. This evidence includes the first significant increase in brain size in the hominid lineage over that of the apes and the advent of flaked stone tool use.

But Blumenschine is looking for more than stones and bones. His goal is an understanding of the relationship of these earliest men and women to the landscape on which they lived and shared with its other inhabitants. To do so necessitated a different investigative approach. Earlier investigators at Olduvai dug vertically at a few large sites, attempting to trace the nature of anatomical or technological change through time. Blumenschine and his colleagues have taken a more horizontal approach, excavating and sampling in discrete time intervals over broad areas. They have been sampling the environments and activity traces of hominids in specific time ranges, correlating the nature of hominid activities as seen in the stone artifacts and butchered bones to the environments in which they are found.

“This horizontal approach can provide a broader picture of the life of our early ancestors, ultimately allowing us to be able to understand the nature and extent of the environmental pressures were that selected for the suite of behaviors that we see in early Homo,” Blumenschine said.

The research is documenting an important change in the ancient way of life, a dietary shift where the largely plant-eating heritage of primates suddenly changes to include animal foods. Blumenschine said that this also represents a profound ecological change in the relationship of early humans to large carnivores that had previously been their predators. Homo was beginning to compete with these carnivores on a new level, not necessarily in hunting, but at least in fighting for the leftovers of carnivore meals.