Parapatric diversification after post-glacial range expansion in the gall flyUrophora cardui(Tephritidae)

Aim  Primary and secondary genetic clines in post-glacial colonized regions have different implications for biogeographic distributions and the origin of species. Primary clines arise in situ after colonization as adaptive responses to environmental gradients, while secondary clines are caused by contact between vicariant lineages. Here we analyse primary versus secondary origin of a genetic cline in the tephritid fly Urophora cardui in Jutland, Denmark, in a post-glacial landscape. Location  Western Palaearctic. Methods  Phylogeographic and demographic analyses of U. cardui based on mitochondrial DNA (mtDNA) genealogies, hierarchical genetic variance tests based on allozymes and distributi…