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bioRxiv · 10.1101/420380

Host defense triggers rapid adaptive radiation in experimentally evolving parasites

Bush, S. E.·Villa, S. M.·Altuna, J. C.·Johnson, K. P.·Shapiro, M. D.·Clayton, D. H.
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Abstract

Adaptive radiation occurs when the members of a single lineage evolve different adaptive forms in response to selection imposed by competitors or predators. Iconic examples include Darwins finches, Caribbean anoles, and Hawaiian silverswords, all of which live on islands. Parasites, which live on host \"islands,\" show macroevolutionary patterns consistent with adaptive radiation in response to host-imposed selection. Here we show rapid adaptive divergence of experimentally evolving feather lice in response to preening, the main host defense. We demonstrate that host defense exerts strong phenotypic selection for crypsis in lice transferred to different colored rock pigeons (Columba livia). During four years of experimental evolution ([~]60 generations), the lice evolved heritable differences in color. The color differences spanned the phenotypic distribution of congeneric species of lice adapted to other species of pigeons. Our results indicate that host-mediated selection triggers rapid divergence in the adaptive radiation of parasites, which are among the most diverse organisms on earth. Our research suggests that host defense should be included with competition and predation as a major mechanism driving the evolution of biodiversity by adaptive radiation.

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Bush, S. E., Villa, S. M., Altuna, J. C., Johnson, K. P., Shapiro, M. D., Clayton, D. H.. 2018-09-18. Host defense triggers rapid adaptive radiation in experimentally evolving parasites. https://doi.org/10.1101/420380

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