Ancient DNA: A window to the past of Europe.

OBJECTIVES The history of European populations is characterised by numerous migrations or demographic events that are likely to have had major impacts on the European gene pool patterns. This paper will focus on how ancient DNA (aDNA) data contribute to our understanding of past population dynamics in Europe. METHODS Technological challenges of the palaeogenetic approach will be discussed. With these limitations in mind, it will be shown that the acquisition of aDNA now permits a glimpse of how human genetic diversity has changed, spatially and temporally, in Europe, from the Palaeolithic through to the present day. RESULTS Although early modern human DNA sequences come only from rare exceptionally well-preserved specimens, genetic samples of a reasonable size are becoming available for the Mesolithic and the Neolithic periods, permitting a discussion of regional variation in the inferred mode of the spread of farming. Palaeogenetic data collected for ancient and more recent periods regularly demonstrate genetic discontinuity between past and present populations. CONCLUSIONS The results indicate that only large diachronic aDNA datasets from throughout Europe will permit researchers to reliably identify all demographic and evolutionary events that shaped the modern European gene pool.