European Genetic Diversity through Space and Time

Abstract

sions are nevertheless to be confirmed through further studies, as they are challenged in the next two papers by Barbujani (University of Ferrara, Italy) and Currat and Silva (University of Geneva, Switzerland), respectively. Barbujani’s favoured interpretation of the current European genetic variation is a genetic signature of a Neolithic demic diffusion process, as evidence of a Palaeolithic legacy is seriously lacking, he thinks. However, this author agrees that both a model of genealogical continuity since the Palaeolithic and a model of radical demographic replacement in Neolithic times are too simplistic to explain the current observations and should probably be combined into a mixed scenario taking different factors into account like geographic heterogeneity and cultural shifts. Currat and Silva’s claims are more extreme as, for these authors, a great part of the current European diversity clearly traces back to pre-Neolithic times. By reviewing several publications using a spatially explicit simulation framework, they explain how clinal genetic patterns may result from various phenomena, including allele surfing, which could have occurred at different prehistoric periods, were they Neolithic, Mesolithic or Palaeolithic. To reach some consensual scenario between different scholars, the authors underline the need to integrate both ancient and modern DNA data in spatial simulation approaches. This special issue of Human Heredity has been stimulated by a scientific meeting held in Geneva, Switzerland, in January 2013 as the closing conference of a European COST Action (BM0803), also supported by the Swiss National Science Foundation. The main objective of the conference was to round up our knowledge on the genetic diversity and origins of European populations, by taking into account both ancient and modern molecular data and sophisticated data analyses and computer simulation methods that have been developed in the last few decades within the frame of population genetics. As suggested by the subtitle of this issue, the questions we address(ed) are related both to the demographic history of European populations, a subject still at the centre of a heated scientific debate, and to the clinical consequences and implications of such a history, in terms of risk factors in both natural and clinical contexts. To start with, Deguilloux and Mendisco (University of Bordeaux 1, France) illustrate the state of the art of Paleogenetic studies in Europe, underlining the potentials of ancient DNA for reconstructing the European past, but also its limitations due to often poor and heterogeneous sampling. A striking observation done by these authors is the genetic discontinuity between ancient and extant European populations, suggesting population replacements not only between the Paleolithic and Neolithic periods, but also between the Neolithic and today. These concluPublished online: May 21, 2014