Reproductive isolation and environmental adaptation shape the phylogeography of mountain pine beetle ( Dendroctonus ponderosae )
Author(s) -
Dowle Eddy J.,
Bracewell Ryan R.,
Pfrender Michael E.,
Mock Karen E.,
Bentz Barbara J.,
Ragland Gregory J.
Publication year - 2017
Publication title -
molecular ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.619
H-Index - 225
eISSN - 1365-294X
pISSN - 0962-1083
DOI - 10.1111/mec.14342
Subject(s) - biology , haplogroup , mountain pine beetle , phylogeography , population , evolutionary biology , coalescent theory , reproductive isolation , ecology , local adaptation , haplotype , genetics , phylogenetics , demography , sociology , gene , genotype
Abstract Chromosomal rearrangement can be an important mechanism driving population differentiation and incipient speciation. In the mountain pine beetle ( MPB , Dendroctonus ponderosae ), deletions on the Y chromosome that are polymorphic among populations are associated with reproductive incompatibility. Here, we used RAD sequencing across the entire MPB range in western North America to reveal the extent of the phylogeographic differences between Y haplotypes compared to autosomal and X‐linked loci. Clustering and geneflow analyses revealed three distinct Y haplogroups geographically positioned within and on either side of the Great Basin Desert. Despite close geographic proximity between populations on the boundaries of each Y haplogroup, there was extremely low Y haplogroup mixing among populations, and gene flow on the autosomes was reduced across Y haplogroup boundaries. These results are consistent with a previous study suggesting that independent degradation of a recently evolved neo‐Y chromosome in previously isolated populations causes male sterility or inviability among Y haplotype lineages. Phylogeographic results supported historic contraction of MPB into three separate Pleistocene glacial refugia followed by postglacial range expansion and secondary contact. Distinct sets of SNP s were statistically associated with environmental data among the most genetically distinct sets of geographic populations. This finding suggests that the process of adaptation to local climatic conditions is influenced by population genetic structure, with evidence for largely independent evolution in the most genetically isolated Y haplogroup.