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Phylogenetics and introgression of Habronattus jumping spiders using transcriptomes (Araneae:Salticidae)

University of British Columbia

Habronattus is a diverse genus of jumping spiders with complex courtship displays and colourful ornaments in males. A well-resolved species phylogeny would provide an important framework to study these traits, but has not yet been achieved because of conflicting signals from the few genes available. While such discordant gene trees could be the result of deep coalescence in the recently diverged group, there are many indications that hybridization may have occurred and could be the source of conflict. To infer Habronattus phylogenetic relationships and to investigate the cause of gene tree discordance, we assembled transcriptomes for 34 Habronattus species and 2 outgroups. We conducted a concatenated phylogenetic analysis using Maximum Likelihood for 2.41 Mb of nuclear data and for 12.33 kb of mitochondrial data. The concatenated nuclear phylogeny was resolved with high bootstrap support (95-100%) at most nodes with some uncertainty surrounding the relationships of H. icenoglei, H. cambridgei, and H. oregonensis, and Pellenes cf. levii. There are several nodes of the mitochondrial phylogeny that are incongruent to the nuclear phylogeny and indicate possible mitochondrial introgression: the internal relationships of the americanus and the coecatus group, the relationship between the altanus, decorus, banksi, and americanus group, and between H. clypeatus and the coecatus group. To determine the extent of incomplete lineage sorting (ILS) and introgression, we analyzed gene tree discordance for loci longer than 1 kb using Bayesian Concordance Analysis (BCA) for the americanus group (679 loci) and the viridipes/clypeatus/coecatus (VCC) group (517 loci) and found high levels of genetic discordance, especially in VCC group. Finally, we tested specifically for nuclear introgression in the concatenated nuclear matrix with Patterson’s D statistics and DFOIL. We found nuclear introgression resulting in substantial admixture between americanus group species, and between H. sp. (ROBRT) and the clypeatus group, and more minimal nuclear introgression between the clypeatus group and the coecatus group, and between the americanus group and several distant species. Our results indicate that hybridization may have been historically common between phylogenetically distant species of Habronattus, and that reproductive isolation is yet to be complete across the Habronattus phylogeny.

Text

2015-12-17

Attribution-NonCommercial-NoDerivs 2.5 Canada

http://hdl.handle.net/2429/55870

Zoology

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/2.5/ca/