Biogeographic history of pigeons and doves drives the origin and diversification of their parasitic body lice

Despite their extensive diversity and ecological importance, the history
of diversification for most groups of parasitic organisms remains
relatively understudied. Elucidating broad macroevolutionary patterns of
parasites is challenging, often limited by the availability of samples,
genetic resources, and knowledge about ecological relationships with their
hosts. In this study, we explore the macroevolutionary history of
parasites by focusing on parasitic body lice from doves. Building on
extensive knowledge of ecological relationships and previous phylogenomic
studies of their avian hosts, we tested specific questions about the
evolutionary origins of the body lice of doves, leveraging whole genome
data sets for phylogenomics. Specifically, we sequenced whole genomes from
68 samples of dove body lice, including representatives of all body louse
genera from 51 host taxa. From these data, we assembled >2,300
nuclear genes to estimate dated phylogenetic relationships among body lice
and several outgroup taxa. The resulting phylogeny of body lice was well
supported, although some branches had conflicting signal across the
genome. We then reconstructed ancestral biogeographic ranges of body lice
and compared the body louse phylogeny to phylogeny of doves, and also to a
previously published phylogeny of the wing lice of doves. Divergence
estimates placed the origin of body lice in the late Oligocene. Body lice
likely originated in Australasia and dispersed with their hosts during the
early Miocene, with subsequent codivergence and host switching throughout
the world. Notably, this evolutionary history is very similar to that of
dove wing lice, despite the stronger dispersal capabilities of wing lice
compared to body lice. Our results highlight the central role of the
biogeographic history of host organisms in driving the evolutionary
history of their parasites across time and geographic space.