How to Survive the Bottleneck in Tanzania

Pamela Willoughby of the University of Alberta may have uncovered evidence of continuous human occupation of two sites in Tanzania dating back at least 200,000 years. At Mlambalasi, fragments of a human skeleton dating to the late Pleistocene Ice Age were discovered. During this time period, it is thought that human populations dropped to near extinction levels. The other site, Magubike, has a large rock shelter with an overhanging roof. Human teeth, animal bones, shells, and stone tools have been found in its occupation layers dating from the middle Stone Age through the Iron Age. Radiocarbon dating and electron spin resonance are being used to test the archaeological deposits. “What’s important about the whole sequence is that we may have a continuous record of human occupation. If we do—and we can prove it through these special dating techniques—then we have a place people lived in over the bottleneck,” she said.