interdisciplinary branch of anthropology concerned with the origins and development of early humans. Fossils are assessed by the techniques of physical anthropology, comparative anatomy, and the theory of evolution. Artifacts, such as bone and stone tools, are identified and their significance for the physical and mental development of early humans interpreted by the techniques of archaeology and ethnology. Dating of fossils by geologic strata, chemical tests, or radioactive-decay rates requires knowledge of the physical sciences.