Data from: 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 historical data.
Despite a strong support to the selected scenario for our dataset, the ABC
approach showed a low power to discriminate among scenarios on average and
a low ability to accurately estimate effective population sizes and
divergence dates, probably due to the temporal scale of the study. This
study provides an unusual opportunity to test ABC analysis in a system
with a well documented demographic history and identify discrepancies
between the results of historical, classical population genetic and ABC
analyses. The results also provide valuable insights into genetic
processes at work at a fine spatial and temporal scale in range change and
colonization.