Phylogeny And Historical Biogeography Of The Order Pandanales

Abstract

Reconstruction of the dispersal history and formation of modern ranges of various taxa is one of the actual problems of modern biogeography. Molecular genetic biogeography based on the analysis of phylogenetic relationships of taxa of different levels began to develop actively at the end of the XX century. Currently, this method is the most objective and represents the basis for reconstruction of scenarios of the origin and dispersal of various groups of plants. Due to recent transformation of views on the phylogenetic relationships of Pandanales, the reconstruction of tracks and modes of dispersal of representatives of the order Pandanales becomes an actual task. Representatives of all 5 families of Pandanales sensu APG IV were selected for the study and two cladograms were constructed. Based on the molecular-genetic cladistic method the region of hypothetical origin and probable dispersal scenarios of the families of the order Pandanales were determined. The order Pandanales is treated as originated in Laurasia and its differentiation began on the territory of Tibet. Dispersal of the representatives of the basal family Velloziaceae took place by long-distance transport via the Bering Land Bridge to South America (approximately 115 Mya). Velloziaceae dispersed in the New World vicariously in South America, then it was distributed to sub-Atlantic Africa by long-distance transport, and finally also vicariously to the east, south and north of the continent. It is shown, that the modern range of the representatives of rest Pandanales is the result of both types of dispersal – vicariously and long-distance transport.