The aim of this chapter is to provide an account of the complex history of Mediterranean faunas as they evolved from the end of the Pliocene about 1.8 million years ago until the present day. Reconstructing this history is difficult because the Mediterranean basin is one of the most complex regions in the world and is characterized by significant geographical and topographical variation. The Mediterranean basin was formed during the Tertiary by the convergence of the African and Eurasian tectonic plates, in combination with several African microplates, Iberia, and two main African promontories: Apulia in the west and Arabia in the east (Chapter 1 and Dercourt et al. 1986). Where the African and Eurasian plates meet, seismic and volcanic activity have combined with other processes to form a very heterogeneous region. High mountains and deeply dissected topography form the main part of a coastline some 46,000 km in length, 18,000 of which are island shores (Chapter 13). A dominant feature of the region, which has had many consequences for species diversity and the process of differentiation, is the striking contrast between the northern half of the basin with its many large peninsulas—Iberian, Apennine, Balkan, and Anatolian—and the southern half with its more or less rectilinear shorelines. In addition, there is a marked biogeographical contrast between the western and the eastern halves of the Mediterranean, the former having shifted somewhat to the north with respect to the latter. The line separating the two north–south ranges in each half of the basin runs approximately along the 36th parallel in the western half and the 33rd in the eastern half. In the western half, west of the Sicily–Cap Bon line, biota are more boreal in character and overlap to a large degree with those of central Europe. To the east, biota have more affinities with central Asia (Blondel and Aronson 1999). Modern patterns of regional floral and faunal diversity mostly result from differential speciation and extinction rates during the Quaternary (Chapter 4).
Biogeography of neutral genes and recent evolutionary history of pines in the Mediterranean Basin
