An integrative multi-approach workflow resolves species limits in the southernmost members of the Liolaemus kingii group (Squamata: Liolaemini)

Abstract

Recent conceptual and methodological advances have enabled an increasing number of studies to address the problem of species delimitation in a comprehensive manner. This is of particular interest in cases of species whose divergence times are recent, where the conclusions obtained from a single source of evidence can lead to the incorrect delimitation of entities or assignment of individuals to species. The southernmost species of the Liolaemus kingii group (namely L. baguali, L. escarchadosi, L. sarmientoi, L. tari and the candidate species L. sp. A) show widely overlapping distributions as well as recent mitochondrial divergences, thus phylogenetic relationships and species boundaries are ambiguous. Here we use a comprehensive approach to assess species limits and corroborate their status as independent lineages through the use of four sources of molecular and morphological information (mitochondrial cytochrome-b, nuclear sequences collected by ddRADseq, and linear, meristic and landmark-based morphometrics). We found concordance among the different datasets, but signs of admixture were detected between some of the species. Our results indicate that the L. kingii group can serve as a model system in studies of diversification accompanied by hybridization in nature. We emphasize the importance of using multiple lines of evidence in order to solve evolutionary stories, and minimizing potential erroneous results that may arise when relying on a single source of information.