Conserving hybrid genotypes: monitoring genetic divergence under recent climate warming regimes

Global warming has increased the potential for bivoltinism at higher latitudes/altitudes, but has also contributed significantly to differential movement of many traits, including species diagnostic traits across the landscape of the historical hybrid zone. Independent trait movement across a well-studied mosaic-like hybrid zone between Papilio glaucus and P. canadensis has generated different locally-adapted interspecific recombinant hybrid genotypes. High recombination rates on the X (=Z) chromosome has resulted in temporal delays for post-diapause adult emergences from pupae, which in mountainous eastern USA has either created (in the North) , conserved (WVA), or contracted (in the South) the thermal niche for these “late flight” recombinant populations. Strong divergent selection and local adaptations have interacted during the warming climate since 1998 to potentially contributing to the origins of the putative hybrid mountain swallowtail butterfly species, P. appalachiensis. The role of different local host plant availability/adaptations suggests that the late flight populations of recombinant hybrids may favor trees with late bud-break and slower maturation.