Deep mitochondrial DNA phylogeographic divergence in the threatened aoudad Ammotragus lervia (Bovidae, Caprini).

The aoudad or Barbary sheep (Ammotragus lervia) is a threatened ungulate emblematic of North Africa, whose population structure and subspecific taxonomy have not been examined genetically. This knowledge is essential and urgently needed to inform ongoing conservation and management efforts. We analysed the mitochondrial cytochrome b gene and four nuclear genes (casein kappa, spectrin beta nonerythrocytic 1, thyroglobulin, thyrotropin subunit beta) for the first phylogeographic survey of the aoudad, and uncovered a deep Mediterranean-Saharan mitochondrial split separating two highly distinct evolutionary lineages. Their level of divergence is greater than or comparable to those observed between several pairs of congeneric species of different caprine genera. The split was estimated to have occurred in the Early Pleistocene, about 1.3 million years ago. None of the four nuclear genes surveyed, chosen because they have been used in phylogeographic and species-level phylogenetic studies of bovids, allowed us to detect, likely due to their slow evolutionary rate, the substantial and geographically coherent subdivision revealed by mitochondrial DNA. This study is evidence and testament to the ability of mitochondrial DNA, probably unrivalled by any other single-locus marker, as an exploratory tool for investigating population genealogy and history and identifying potential evolutionarily significant units for conservation in animals.

Genetic evidence supporting the taxonomic separation of the Arabian and Northwest African subspecies of the desert hedgehog (Paraechinus aethiopicus).

Traditional subspecies call attention to differences between geographic populations with research potential, but their value is often in need of revision. Genetic data can be useful for evaluating the taxonomic validity of historical species and subspecies designations or for identifying morphologically cryptic divergent lineages worthy of further in-depth taxonomic study. The desert hedgehog (Paraechinus aethiopicus) has a wide but fragmented distribution in arid and semi-arid habitats from the northwest to the northeast of Africa and southwestern Asia, and its taxonomy is still unclear. We used mitochondrial (cytochrome b, Cyt b, and 12S ribosomal RNA, 12S) and nuclear (breast cancer type 1 susceptibility protein, BRCA1, and apolipoprotein B, Apob) DNA sequence data to assess the degree of genetic divergence between two of its three major proposed subspecies: Arabian (P. a. dorsalis) and Northwest African (P. a. deserti); this is the first molecular evaluation of the taxonomy of P. aethiopicus. Phylogenetic analyses, comparison of interspecific and intraspecific genetic distances observed across hedgehog species, and molecular species delimitation methods (distance-based clustering and tree-based), all indicate a level of genetic differentiation between dorsalis and deserti that is compatible with their taxonomic separation. Their divergence in the studied genes were consistently comparable to, or greater than, several intrageneric and a few intergeneric distances in hedgehogs. The Cyt b net Kimura 2-parameter distance between dorsalis and deserti was 10.8±1.3%, which is about the mean between congeneric species in reviews of Cyt b distances for mammals. This study, as a test of the genetic distinctiveness of dorsalis and deserti, suggests that they represent evolutionarily significant units and flags them for future phylogeographic and taxonomic investigations.