Postdoctoral Researcher University of Florida Gainesville, Florida
The rapid evolution and species-specificity of intromittent arthropod genitalia are widely accepted as a ‘near universal’ biological phenomenon, making them enticing candidate character sets to taxonomists hoping to delimit otherwise morphologically cryptic taxa. However, this paradigm may hold for some but not all taxa. The evidence cited in the taxonomic literature is often self-fulfilling: It posits the taxonomic utility of genitalia a priori and does not account for the possibility of intraspecific variation. If undetected, high intraspecific variation in a species complex carries the risk of over-splitting species. Therefore, these character sets must be tested rigorously and quantitatively with broad population-level sampling and integration with other methods of delimitation. In this study, we integrate phylogenomic and morphological methods of delimitation and test the species-specificity and amount of phenotypic variation expressed in the male genitalia of morphologically cryptic ant species in the genus Nylanderia. Nylanderia is a large, near-globally distributed genus with 125 described species and an estimated hundreds more unknown to science. At least 15 species are ‘globetrotting’ species that frequently travel outside their native ranges via human-mediated dispersal, most of which are difficult to identify and belong to morphologically cryptic species complexes.
