Comparing rates of introgression in parasitic feather lice with differing dispersal capabilities

Jorge Doña,Andrew D Sweet,Kevin P Johnson

doi:10.1038/s42003-020-01345-x

Jorge Doña, Andrew D Sweet + Show 1 more

Open Access

https://doi.org/10.1038/s42003-020-01345-x

Copy DOI

Abstract

Organisms vary in their dispersal abilities, and these differences can have important biological consequences, such as impacting the likelihood of hybridization events. However, there is still much to learn about the factors influencing hybridization, and specifically how dispersal ability affects the opportunities for hybridization. Here, using the ecological replicate system of dove wing and body lice (Insecta: Phthiraptera), we show that species with higher dispersal abilities exhibited increased genomic signatures of introgression. Specifically, we found a higher proportion of introgressed genomic reads and more reticulated phylogenetic networks in wing lice, the louse group with higher dispersal abilities. Our results are consistent with the hypothesis that differences in dispersal ability might drive the extent of introgression through hybridization.

Highlights

Organisms vary in their dispersal abilities, and these differences can have important biological consequences, such as impacting the likelihood of hybridization events
Dispersal is the permanent movement of organisms away from their place of origin. It is a fundamental process in biology with major implications at multiple scales of organization[1,2,3,4], including the reproduction of individuals, the composition of populations and communities, and the geographical distribution of species[2,5]. Organisms differ in their dispersal abilities, and these differences have an impact on their biology, such as on the distributional range of a species or gene flow between populations[6]
We predicted that wing lice, which have higher dispersal abilities and higher odds of encountering individuals of a different louse species on the same host, should show more extensive evidence of introgression (Fig. 1). Both approaches revealed highly concordant results: higher levels of introgression among species of wing lice compared to body lice

Summary

Introduction

Organisms vary in their dispersal abilities, and these differences can have important biological consequences, such as impacting the likelihood of hybridization events. The ecological replicate system of wing and body lice (Insecta: Phthiraptera) of pigeons and doves (Aves: Columbidae) has proven to be an ideal system for comparing the impact of dispersal differences on other aspects of biology, such as population structure and codivergence[7,15,16,17,18] This is an excellent system in which to assess the effect of differences in dispersal capabilities on levels of introgression because both of these lineages of feather lice: (1) drastically differ in their dispersal ability[19,20,21], (2) co-occur across the diversity of pigeons and doves, and (3) have the same basic life history and diet[15,18,22]. Wing lice have a higher rate of host-switching[15,16,23] (i.e., successful colonization of new host species) and of straggling[24] (i.e., dispersal to new host species without reproduction on that new host)

Methods

Results

Conclusion