A complex pattern of post‐divergence expansion, contraction, introgression, and asynchronous responses to Pleistocene climate changes in twoDipeltasister species from western China

The well‐known vicariance and dispersal models dominate in understanding the allopatric pattern for related species and presume the simultaneous occurrence of speciation and biogeographic events. However, the formation of allopatry could postdate the species divergence. We examined this hypothesis using DNA sequence data from three chloroplast fragments and five nuclear loci of Dipelta floribunda Maxim. and D. yunnanensis Franch, two shrub...