Phylogenetic History and Phylogeographic Patterns of the European Wildcat (Felis silvestris) Populations

The European wildcat is an iconic small-sized predator that is still threatened by habitat fragmentation, accidental or illegal killings, and hybridization with domestic cats. However, phylogenetic and phylogeographic patterns of the taxon, though essential to design appropriate long-term conservation management actions, have been poorly investigated. Therefore, in this study, for the first time, we describe the most geographically-representative evolutionary history of the species in Europe based on mitochondrial DNA sequences. Our results clearly show that the European wildcat genetic variability was mainly originated during Pleistocene climatic oscillations and successively modeled by both historical natural gene flow among wild lineages and more recent wild x domestic anthropogenic hybridization events. Disentangling phylogenetic and phylogeographic patterns is fundamental to reconstruct the evolutionary histories of taxa and assess their actual conservation status. Therefore, in this study, for the first time, the most exhaustive biogeographic history of European wildcat (Felis silvestris) populations was reconstructed by typing 430 European wildcats, 213 domestic cats, and 72 putative admixed individuals, collected across the entire species' distribution range, at a highly diagnostic portion of the mitochondrial ND5 gene. Phylogenetic and phylogeographic analyses identified two main ND5 lineages (D and W) roughly associated with domestic and wild polymorphisms. Lineage D included all domestic cats, 83.3% of putative admixed individuals, and also 41.4% of wildcats; these latter mostly showed haplotypes belonging to sub-clade Ia, that diverged about 37,700 years ago, long pre-dating any evidence for cat domestication. Lineage W included all the remaining wildcats and putative admixed individuals, spatially clustered into four main geographic groups, which started to diverge about 64,200 years ago, corresponding to (i) the isolated Scottish population, (ii) the Iberian population, (iii) a South-Eastern European cluster, and (iv) a Central European cluster. Our results suggest that the last Pleistocene glacial isolation and subsequent re-expansion from Mediterranean and extra-Mediterranean glacial refugia were pivotal drivers in shaping the extant European wildcat phylogenetic and phylogeographic patterns, which were further modeled by both historical natural gene flow among wild lineages and more recent wild x domestic anthropogenic hybridization, as confirmed by the finding of F. catus/lybica shared haplotypes. The reconstructed evolutionary histories and the wild ancestry contents detected in this study could be used to identify adequate Conservation Units within European wildcat populations and help to design appropriate long-term management actions.