Integrated methods clear muddied waters in the phylogeography of the Notomicrus traili complex (Coleoptera: Noteridae)

The aquatic beetle genus Notomicrus has shown utility for testing hypotheses of biogeographic evolution at deeper, global scales. However, investigations of the Notomicrus traili species complex has shown that multiple phylogenetically distinct clades share overlapping distributions and individuals morphologically attributable to described species were recovered as polyphyletic. As such, this group is a prime candidate for the application of genomic methods to investigate phylogeographic patterns and shallow scale drivers of evolution. Here we integrate whole genomes and UCE data captured with a custom probe set (Noteridae 3.4Kv1) to construct a dataset with robust population-level sampling that includes 70 traili group individuals from across the range of the complex. We reconstruct a scaffolding phylogeny of the traili group and estimate divergence times. We then harvest single nucleotide polymorphism (SNP) data and conduct population genetic analyses to investigate patterns of ancestry, evolution, and genetic clustering as it relates to the geographic distribution of populations across South America and the neotropics. Discussed are the implications for population interconnectivity, gene flow and the geographic influence on diversification.