This volume of papers delivered to The Royal Society in February of 1992 explores the debate over the "single center" hypothesis of human origins versus "multi-regional evolution." Over the last five years there has been growing support for a recent "Out of Africa" origin of modern humans--based on fresh interpretations of the palaeoanthropological and archaeological evidence, new applications of physical dating techniques to important sites, and a greatly increased genetic data base on recent human variation and its geographical patterning. But there has also been a parallel growth of doubts about interpretations of the new evidence from some workers. This book provides a review of recent progress and allows some of these doubts to be aired and discussed. In addition to the editors, the contributors are O. Bar-Yosef, A. M. Bowcock, P. Brown, H. J. Deacon, L. L. Cavalli-Sforza, J. D. Clark, R. Grun, J.-J. Hublin, A. A. Lin, G. H. Miller, J. L. Mountain, H. P. Schwarcz, N. J. Shackleton, F. H. Smith, and M. Stoneking. Originally published in 1993. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.