Spatial impacts on gene flow may hinder linking phylogeographic data to macroevolutionary patterns

Abstract Biogeography relies on estimates of phylogeny and gene flow to test hypotheses. Established theory posits: (i) gene flow varies non-randomly with respect to geography and (ii) gene flow can mislead phylogenetic inference. These findings, often viewed in isolation, together suggest that spatial impacts on gene flow could bias biogeographic inference. For example, whenever a ‘peripheral’ population is isolated and inferred as sister to a ‘core’ clade of adjacent populations that exchange