Crystal Structure of the 20 <i>S</i> Proteasome from the Archaeon <i>T. acidophilum</i> at 3.4 Å Resolution

Three archaeological sites at Katanda on the Upper Semliki River in the Western Rift Valley of Zaire have provided evidence for a well-developed bone industry in a Middle Stone Age context. Artifacts include both barbed and unbarbed points as well as a daggerlike object. Dating by both direct and indirect means indicate an age of ∼90,000 years or older. Together with abundant fish (primarily catfish) remains, the bone technology indicates that a complex subsistence specialization had developed in Africa by this time. The level of behavioral competence required is consistent with that of upper Paleolithic Homo sapiens sapiens . These data support an African origin of behaviorally as well as biologically modern humans.