The role of hybridization during ecological divergence of southwestern white pine (Pinus strobiformis) and limber pine (P. flexilis)

This study uses range wide ddRAD-seq data from two species of Pines and their hybrid zone to explore the role of demography and selection on speciation. Our study dwells into the importance of extrinsic barriers as the initiators of speciation. We use an array of methods, ranging from niche modeling, demographic modeling from the genetic data, and cline analyses to arrive at a conclusion of divergence with gene flow and a primary role of extrinsic factors in facilitating speciation.