Integrative phylogeographical and ecological analysis reveals multiple Pleistocene refugia for Mediterranean Daboia vipers in north-west Africa

Numerous works have related phylogeographical patterns of north African Mediterranean biota to Pleistocene climatic oscillations. The application of complementary paleoclimate reconstructions, however, remains scarcely used. North African Daboia vipers comprise two Mediterranean generalist taxa, D. mauritanica and D. deserti, with controversial systematic and range delimitations. We combined phylogeographic and ecological niche analyses to unveil biogeographical scenarios for the evolution of these taxa. Phylogeographic analyses (two mitochondrial gene fragments) resolved a monophyletic lineage, which diverged from D. palaestinae at the Miocene, further structured in seven sublineages with mostly allopatric distributions, six of which endemic to north-west Africa having diversified during the Pleistocene. Paleoclimatic reconstructions (four ecological modelling algorithms) of species ranges for three past periods (Last Inter Glacial, Last Glacial Maximum and Middle Holocene) suggested range contractions during warm periods and range expansions during cold periods. Stable climatic areas mostly fit potential refugia for lineages occurring in Morocco. Niche overlap analyses based on spatial genetic interpolations to delimitate lineages occurrence demonstrated lack of niche divergence among lineages. Our findings support an allopatric diversification process in Daboia driven by Pleistocene climatic oscillations, which should be expected in other Mediterranean generalist species from north Africa. Furthermore, D. deserti is identified as an invalid taxon.