Out of North Africa by different routes: phylogeography and species distribution model of the western Mediterranean Lavatera maritima (Malvaceae)

Despite the importance of the North African region in the complex climatic and geological history of the western Mediterranean basin, the level of sampling of this region in biogeographical and phylogeographical studies is much lower than in the European region. Aiming to contribute to filling this gap, the evolutionary history of Lavatera maritima is reconstructed using sequence data from three plastid DNA regions (trnD-trnT, trnG, matK), species distribution modelling and divergence time analysis. Of the nine haplotypes identified, six occur in North Africa and four are exclusive to that region. Divergence from its sister species is estimated to have occurred in the Plio-Pleistocene (c. 2.77 Mya) and projection of the climatic model to the Last Interglacial indicates low suitability for this species in Europe. North Africa is inferred to contain the highest genetic diversity for this species and is thought to be the source for the colonization of Europe. The data suggest that colonization occurred not only by land across Iberia northwards to southern France, but also by long-distance dispersal (LDD) between continents and islands. The existence of successful, possibly bird-mediated LDD events is consistent with the specific niche (organic matter-rich, limestone cliffs) and the lack of a clear phylogeographical structure found.