Reconstruction of a beech population bottleneck using archival demographic information and Bayesian analysis of genetic data

Range expansion and contraction has occurred in the history of most species and can seriously impact patterns of genetic diversity. Historical data about range change are rare and generally appropriate for studies at large scales, whereas the individual pollen and seed dispersal events that form the basis of geneflow and colonization generally occur at a local scale. In this study we investigated range change in Fagus sylvatica on Mont Ventoux, France, using historical data from 1838 to the present and Approximate Bayesian Computation (ABC) analyses of genetic data. From the historical data we identified a population minimum in 1845 and located remnant populations at least 200 years old. The ABC analysis selected a demographic scenario with three populations, corresponding to two remnant populations and one area of recent expansion. It also identified expansion from a smaller ancestral population but did not find that this expansion followed a population bottleneck, as suggested by the ...