Early phases of a successful invasion: mitochondrial phylogeography of the common genet (Genetta genetta) within the Mediterranean Basin

摘要

The Mediterranean Basin, connected by cultural exchanges since prehistoric times, provides an outstanding framework to study species translocations. We address here the early phases of the successful invasion of the common genet (Genetta genetta), a small carnivoran supposedly introduced from Africa to Europe during historical times, by assessing mitochondrial nucleotide variability in 134 individuals from its native and invasive ranges. We identify four lineages within the native species range [northern Algeria, Peninsular Arabia, southern Africa and western Africa + Maghreb (including northern Algeria)], in contradiction with morphological taxonomy. We propose that the co-occurrence in Maghreb of two divergent lineages (autochthonous and western African) is due to secondary contact through intermittent permeability of the Saharan belt during the Plio-Pleistocene. Estimates of coalescence time and genetic diversity, in concert with other available evidences in the literature, indicate that the origin of European populations of common genets is in Maghreb, possibly restricted to northern Algeria. The autochthonous mitochondrial lineage of Maghreb was the only contributor to the European pool, suggesting that translocations were associated to a cultural constraint such as a local use of the species, which might have artificially excluded the western African lineage. Haplotype network and nested clade analysis (NCA) provide evidence for independent events of introductions throughout Spain (Andalucia, Cataluña, and the Balearic Isl.)—and, to a lesser extent, Portugal—acting as a ‘translocation hotspot’. Due to the reduced number of northern Algerian individuals belonging to the autochthonous mitochondrial lineage of Maghreb, it remains impossible to test hypotheses of historical translocations, although a main contribution of the Moors is likely. Our demographic analyses support a scenario of very recent introduction of a reduced number of individuals in Europe followed by rapid population expansion. We suggest that an exceptional combination of factors including multiple translocations, human-driven propagation across natural barriers, and natural processes of colonization allowed by a wide ecological tolerance, promoted the successful spread of the common genet into Europe.