A new model for large-scale population dynamics: quantifying phylogeography Journal Article

Author(s): Barton, Nicholas H; Kelleher, Jerome; Etheridge, Alison M
Article Title: A new model for large-scale population dynamics: quantifying phylogeography
Abstract: Classical models of gene flow fail in three ways: they cannot explain large-scale patterns; they predict much more genetic diversity than is observed; and they assume that loosely linked genetic loci evolve independently. We propose a new model that deals with these problems. Extinction events kill some fraction of individuals in a region. These are replaced by offspring from a small number of parents, drawn from the preexisting population. This model of evolution forwards in time corresponds to a backwards model, in which ancestral lineages jump to a new location if they are hit by an event, and may coalesce with other lineages that are hit by the same event. We derive an expression for the identity in allelic state, and show that, over scales much larger than the largest event, this converges to the classical value derived by Wright and Mal├ęcot. However, rare events that cover large areas cause low genetic diversity, large-scale patterns, and correlations in ancestry between unlinked loci.
Keywords: coalescence; phylogeography; diffusion; gene flow; extinction; isolation by distance
Journal Title: Evolution; International Journal of Organic Evolution
Volume: 64
Issue 9
ISSN: 0014-3820
Publisher: Wiley-Blackwell  
Date Published: 2010-09-01
Start Page: 2701
End Page: 2715
DOI: 10.1111/j.1558-5646.2010.01019.x
Open access: no