Ancient DNA studies in physical anthropology

Nucleic acids are preserved in prehistoric samples under a wide range of de positional environments. The development of new molecular methods, especial ly the polymerase chain reaction, has made possible the recovery and manipu lation of these molecules, and the subsequent molecular genetic characteriz ation of the ancient samples. The analysis of ancient (a)DNA is complicated by the degraded nature of ancient nucleic acids, as well as the presence o f enzymatic inhibitors in aDNA extracts. We review aspects of ancient DNA p reservation, a variety of methods for the extraction and amplification of i nformative DNA segments from ancient samples, and the difficulties encounte red in documenting the authenticity of ancient DNA template. Studies using aDNA to address questions in human population history or human evolution ar e reviewed and discussed. Future prospects for the field and potential dire ctions for future aDNA research efforts in physical anthropology are identi fied.