A phylogenomic framework of the ant genus Tapinoma (Formicidae: Dolichoderinae)

The ant genus Tapinoma Foerster, 1850 is a moderately diverse group (72 valid species) that occurs worldwide. It includes the tramp species T. melanocephalum, whose evolutionary history and biogeographic origin and species limits remain unclear. A time-calibrated phylogeny and a biogeographic history inference of the genus was performed based on thousands of Ultraconserved Element (UCE) loci, as well as SNPs from UCE loci and COI sequences to analyze species boundaries focused on T. melanocephalum, under two approaches (genomic and mitochondrial DNA). We recovered Tapinoma as monophyletic and the genus Aptinoma as the sister group with an estimated origin of the genus in the middle Eocene in the Australasian or Oriental region. The phylogenetic and species delimitation approaches show two sister lineages in T. melanocephalum: one largely restricted to the Oriental region (recently described as T. pithecorum) and another distributed worldwide. Genetic population analysis confirms significant evolutionary divergence among sampled T. melanocephalum, and heterogeneous genetic structure with a weak relationship between genetic differentiation and geographic distance. This ubiquitous species exhibits an ecological shift of habitat preference from undisturbed to urban environments.