Site location in Tanzania

Technological advances of the last 100 years indicate human culture is developing at a furious pace. But life on earth might not always have been moving this quickly.

Dr. Pamela Willoughby, an associate professor in the Department of Anthro-pology, has been conducting a lengthy study that not only presents new material about the evolution of anatomically modern humans (Homo sapiens), but also challenges the long-standing theories of archaeology experts around the world.

A popular belief in academic circles is that approximately 30,000 years ago, a time representing the dawning of the Later Stone Age in Africa (LSA), our own species appeared, biologically and culturally.

At that time, something triggered in the human brain, according to the theory, and gave these early people the capability to produce elaborate tools and other traces of culture, like jewelry and cave drawings.

But Willoughby disagrees.

"I'm just not convinced of this. It could easily have been a more gradual thing, since African populations before this were already biologically the same as we."

She has found archaeological samples of tools and fossils in Africa, which are older than 30,000 years, indicating humans on the continent may have had the capacity for culture and tool-making earlier than originally thought.

Later Stone Age finished tools, called crescents, which would be put into a small handle to use for cutting or scraping.

"Since 1987, we've had ways of dating things that are older than 40,000 years," she explains. "We now know there are sites with modern human remains that are up to 200,000 years old in Africa. People of the Middle Stone Age (MSA, 200,000 to 40,000 years ago) were biologically modern humans. But was their culture also modern?"

Willoughby believes this may be the case but that hypothesis is in direct conflict with the work of Dr. Richard Klein of Stanford University, known as an authority on human evolution.

Klein is a proponent of the Out of Africa theory, which suggests the ancestors of modern humans originated in Africa and proceeded to emigrate across the globe starting about 40,000 years ago. In his book The Human Career, Klein argues there were indeed big changes approximately 30,000 years ago, setting the stage for humans to develop complex cultures and then migrate out.

"He's convinced it doesn't matter that there were modern humans during the MSA in Africa, because they were not culturally modern - which is why I want to write a book," she laughs. "I'm firmly convinced the Out of Africa theory is right, but I don't believe they were stupid and clueless or had primitive or pre-cultural adaptations (prior to 30,000 years ago)."

The main focus of her field work is in southwestern Tanzania, home to many archaeological sites with artifacts and fossils from the MSA and LSA. The research is concentrated in an area of the Songwe River of the Lake Rukwa rift valley, which has a series of terraces with associated archaeological sites. Other sites are found in rockshelters, places where large boulder overhangs provided a spot for human settlement. More than 21,000 LSA artifacts were excavated from a rockshelter in a single hole that measured one metre square with a depth of 1.45 metres below the surface.

Willoughby says composite tools (small blades and geometric pieces attached to handles) appear in Africa much earlier than they do in Europe. What she and her team hope to find in Tanzania is a progression of tool development from the MSA to LSA as they dig deeper into the terraces and rockshelters.

April 28, 2000

"We're still trying to find that magic site that has it all," she says.

"Things are sort of changing but not radically. It seems to be a gradual process. At no point - Bingo! - did modern culture appear. "We really want to find out what changed between the MSA and LSA."

While research into the origin of humans is relatively new, Willoughby sees great importance in the work and in finding the right answers.

"The appeal of it is understanding something about our own history," she says. "It's African history, but it is also the history of the first human populations such as ourselves. The genetic data behind the Out of Africa theory is important for social reasons. All of us have a recent, common ancestor. Biologically, race doesn't mean anything.

"We may be studying the origin of everyone."