9521879 BROOKS The Middle Stone Age is a period when anatomically modern humans replaced more archaic forms. Recent research findings in Africa have shown that economic activities of humans in this time may also have been associated with crucial behavioral changes. Excavation of Middle Stone Age sites is limited, however, and long sequences with good faunal preservation are rare. This project will continue work by an interdisciplinary team of archeologists, paleontologists, geologists, and geochemists at Middle Stone Age and Acheulean sites in the Aduma-Bouri regions of the Middle Awash Valley of Ethiopia. Continued excavations will focus on evidence of human economic activities in association with fossil lake shores and deltaic deposits. Parallel work will continue on the relatively little-known Middle Stone Age industries of the Aduma region and the later Acheulan sites at Bouri in order to establish a chronological and paleoenvironmental relationship between the sequences of these two regions. Research will include stratigraphic, paleolandscape, and paleoenvironmental reconstruction of the Aduma region and establishment of an absolute chronology using several techniques. The project will be coordinated with the work of a team led by T.D. White that is working sites about 30 km to the north. This project will continue what already has been a productive network of sites in central Ethiopia. The excellent preservation of materials has generated new insights into the evolution of marine-related industries. Of special significance is the potential to gain new insights into the behavior transformation of early humans from independent actors into communal entities who work together and employ relatively sophisticated tools.