MOLECULAR PHYLOGENY AND THE HISTORICAL BIOGEOGRAPHY OF THE WARBLERS OF THE GENUS SYLVIA (AVES)

A molecular phylogeny based on DNA/DNA hybridization revealed that the Sylvia-Parisoma complex is monophyletic and includes three main group s of species, the ''mid-European'' warblers, the genus Parisoma, and t he ''eu-Mediterranean'' Sylvia species sensu stricto. The latter can b e assigned to three main clusters, a ''West-Mediterranean'' group, a ' 'Central-Mediterranean group'', and an ''East-Mediterranean'' group. T he radiation of the whole complex is much more ancient than formerly b elieved. It started ca 12-13 Ma ago and the ancestors of the main exta nt groups differentiated during the Pliocene. Only speciation events w ithin the ''eu-Mediterranean'' lineages occurred during the Pleistocen e. The paleoclimatical and paleoecological history of the Mediterranea n region is too complicated to provide any evidence for direct relatio nships between past events and evolutionary steps of these taxa which did not leave any reliable fossil record. However, some major speciati on events may be related to well documented climatical crises as well as paleobotanical data. The largely man-induced extension of matorrals over several millenia presumably extended the range of several specie s that were formerly much more restricted, which complicates reconstru ction of the spatio-temporal course of speciation.