Testing hypotheses of hybrid taxon formation in the shrubby beardtongues (Penstemon subgenus Dasanthera)

Premise
Hybridization is increasingly being identified in the genomes of species across the tree of life. This has led to a general recognition that hybridization plays an important role in the generation of species diversity. While hybridization may increase species diversity directly via the formation of new taxa through hybrid speciation, it may also act indirectly via the exchange of phenotypic and genetic variance between species, which may in turn stimulate future speciation events.
 
Methods
Using high-throughput sequence data, we resolve phylogenetic relationships and investigate the role of hybridization as a diversification mechanism in the shrubby beardtongues (Penstemon subgenus Dasanthera), a group of North American wildflowers that has undergone a recent and rapid adaptive radiation. Specifically, we test four hypotheses of hybrid taxon formation resulting from hybridization between P. davidsonii and P. fruticosus.
 
Key Results
Species tree inference supports the monophyl...