Origin and dynamics of KSxKE hybrid zones
Our molecular data provide several additional perspectives on the KSxKE hybrid zones. Consistent with geographic expectations, stepwise PCoA of the SNPs dataset consistently identified the Condamine (ie. taxon KEm) as the most likely source population for the KE+ parent (Figs. 3b, S1). Second, individuals displayed varying degrees of admixture between their two parental taxa (Fig. S1), indicating that F1 hybrids must be sufficiently fertile to at least produce F2 and/or backcross offspring. Finally, there was no obvious correlation between the distance from the KEm source and the extent of introgression for KE-derived alleles (Figs. 1, S1).