Disentangling lousy relationships: Comparative phylogenomics of two sucking louse lineages parasitizing chipmunks

The evolution of obligate parasites is often interpreted in light of their hosts’ evolutionary history. An expanded approach is to examine the histories of multiple lineages of parasites that inhabit similar environments on a particular host lineage. Western North American chipmunks (genus Tamias) have a broad distribution, a history of divergence with gene flow, and host two species of sucking lice (Anoplura), Hoplopleura arboricola and Neohaematopinus pacificus. From total genomic sequencing, we obtained sequences of over 1100 loci sampled across the genomes of these lice to compare their evolutionary histories and examine the roles of host association in structuring louse relationships. Within each louse species, clades are largely associated with closely related chipmunk host species. Exceptions to this pattern appear to have a biogeographic component, but differ between the two louse species. Phylogenetic relationships among these major louse clades, in both species, are not congru...