The biogeographical patterns of disjunt distribution with special emphasis on the Mediterranean and southern African model

Abstract

Biogeographia vol. XXIX — 2008 (Pubblicato il 30 dicembre 2008) The Mediterranean—southern African disjunct distribution pattern The biogeographical patterns of disjunct distribution with special emphasis on the Mediterranean and southern African model MARCO A. BOLOGNA, PAOLO A. AUDlSIO*, MAURIZIO BlONDI**, ACHILLE CASALE*** Dipzzrtimmto di Biologia Arnbientrzle, Um'z/erritfz Roma Tre, via/e G. Marconi 446, 00146 Rome, Italy e—mzzz'[: bologna @um'r0mrz3. it *Dz}uzrtz'me7zto di Biologirz Arzimzzle e a'el[’U0mo, Sapienza Universitfz dz’ Roma, z/idle del/’Uniz2er5z't£z 32, 00185 Rome, Italy ”‘*Dz‘pzzrtimmto di Scienze Am/vientzzli, Universitfz del/1/lqziilzz, via Vetoio 57%‘, 67100 L i/lqui/zz, Italy ***Dz‘partin2e7zto di Z00/ogia e Gmetiaz evoluzionistiaz, Universitiz di Sasszzri, Via Muroni 25, 07100 Szzmzri, Italy Key words: biogeographical models, disjunction, Mediterranean, southern Africa SUMMARY The authors introduce and shortly discuss the intriguing issue of biogeographical disjunctions, with special emphasis on the Mediterranean—southern African disjunctions, analyzed considering both dispersal and vicariance models. Combined data sets based on both mot holo ical and molecular cues from a relativel lar 6 series ofdifferent . P . . . . V g . . animal and ve etal taxa some of them extensivel discussed in the resent volume) indicate true and si nificant E . . _ Y _ _ 5 _ phylogenetic relationships between Mediterranean and southern African biota. Where molecular data are available, . . . - a . . ., (L the estimated times of divergence frequently supports evidence of an Arid Corridor , or of a Central or Eastern High Africa Corridor”, which connected a number of times in the last 20—25 MY s the European—Mediterranean and eastern/southern African areas, and facilitated species migration northwards and southwards. These corridors allowed the dispersal southwards of several taxa of European—Mediterranean origin, frequently teaching at least the main mountain systems and the coasts of Eastern and SE Africa. On the other hand, several taxa of eastern and southern African origin migrated northwards, colonizing the Mediterranean and southern Palaearctic areas. Finally, secondary radiations at specific level frequently occurred in the last MYs both in Mediterranean and African areas, involving taxa of African and Mediterranean origins, respectively. INTRODUCTION Among the most relevant topics in biogeography, a fundamental role is played by the analysis of the origin and theevolutionary timing of disjunct