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Many parasitic insects, including lice, form close relationships with endosymbiotic bacteria that are crucial for their survival. In this study, we used genomic sequencing to investigate the distribution and evolutionary history of the bacterial genusSodalisacross a broad range of feather louse species spanning 140 genera. Phylogenomic analysis revealed significant diversity amongSodalislineages in feather lice and robust evidence for their independent and repeated acquisition by different louse clades throughout their radiation. Among the 1020 louse genomes analysed, at least 22% containedSodalis, distributed across 57 louse genera. Cophylogenetic analyses between theSodalisand feather louse phylogenies indicated considerable mismatch. This phylogenetic incongruence between lice andSodalis, along with the presence of distantly relatedSodalislineages in otherwise closely related louse species, strongly indicates repeated independent acquisition of this endosymbiont. Additionally, evidence of cospeciation among a few closely related louse species, coupled with frequent acquisition of these endosymbionts from free-living bacteria, further highlights the diverse evolutionary processes shapingSodalisendosymbiosis in feather lice.
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Ongoing hybridization obscures phylogenetic relationships in the Drosophila subquinaria species complex
Abstract Inferring evolutionary relationships among recently diverged lineages is necessary to understand how isolating barriers produce independent lineages. Here, we investigate the phylogenetic relationships between three incompletely isolated and closely related mushroom‐feedingDrosophilaspecies. These species form theDrosophila subquinariaspecies complex and consist of one Eurasian species (D. transversa) and two widespread North American species (D. subquinariaandD. recens) that are sympatric in central Canada. Although patterns of pre‐ and post‐mating isolation among these species are well characterized, previous work on their phylogenetic relationships is limited and conflicting. In this study, we generated a multi‐locus data set of 29 loci from across the genome sequenced in a population sample from each species, and then, we inferred species relationships and patterns of introgression. We find strong statistical support thatD. subquinariais paraphyletic, showing that samples from the geographic region sympatric withD. recensare most closely related toD. recens, whereas samples from the geographic region allopatric withD. recensare most closely related toD. transversa. We present several lines of evidence that both incomplete lineage sorting and gene flow are causing phylogenetic discordance. We suggest that ongoing gene flow primarily fromD. recensintoD. subquinariain the sympatric part of their ranges causes phylogenetic uncertainty in the evolutionary history of these species. Our results highlight how population genetic data can be used to disentangle the sources of phylogenetic discordance among closely related species.
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- PAR ID:
- 10460099
- Publisher / Repository:
- Oxford University Press
- Date Published:
- Journal Name:
- Journal of Evolutionary Biology
- Volume:
- 32
- Issue:
- 10
- ISSN:
- 1010-061X
- Format(s):
- Medium: X Size: p. 1093-1105
- Size(s):
- p. 1093-1105
- Sponsoring Org:
- National Science Foundation
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