Molecular phylogeny of Eremias spp. from Pakistan contributes to a better understanding of the diversity of racerunners

Abstract

Eremias Fitzinger, 1834 is a speciose Eurasian genus of true lizards with approximately 40 species. Eremias species occurring in Pakistan have never been examined before using molecular genetics. In the present study, six out of seven morphologically defined taxa distributed in Pakistan (E. acutirostris, E. aporosceles, E. cholistanica, E. kakari, E. persica, and E. scripta) were studied using mitochondrial (16S rRNA, cytochrome c oxidase subunit I, cytochrome b) and nuclear (Rag1) genes. Data of 29 individuals were included in phylogenies using ENA/GenBank sequences. With a maximum of 20 species per analyzed data set, this study represents the most complete phylogeny of the genus to date. Maximum Likelihood and Bayesian analyses were run for concatenated (3,528 bp) and single-locus data sets and supported by uncorrected p distance calculations to evaluate the phylogenetic placement and divergence of Pakistani taxa. Among the Pakistani taxa, we detected six mostly well-supported and deeply divergent clades (A-F) differing by uncorrected p distances of up to 23.8% for mtDNA (cytb) and 3.3% for the nuclear Rag1 locus. Despite morphological differences between E. aporosceles and E. acutirostris (both clade A), no unambiguous genetic support was found for these two taxa. Therefore, we regard E. aporosceles as a synonym of E. acutirostris. On the other hand, E. persica was found to represent a species complex with deeply diverged clades (E and F) in Pakistan. Eremias cholistanica (clade D) and E. kakari (clade B), two morphologically defined endemic taxa of Pakistan, were revealed as phylogenetically clearly distinct. Eremias scripta (clade C) from Pakistan was found to be genetically deeply divergent compared to sequences of this taxon from Afghanistan and Uzbekistan. Our study provides evidence that the current taxonomy of Eremias does neither reflect the genetic diversity nor the evolutionary history of the genus, necessitating a comprehensive integrative taxonomic revision of the whole genus.