Hacia una biogeografía evolutiva

Abstract

The proliferation of methods in the last decades has led some authors to question whether biogeography is a coherent discipline. Biotas are complex mosaics due to dispersal (expansion of distributions) and vicariance (fragmentation of distributions), having complex, reticulate histories, which necessarily need to be studied through the integration of different methodologies. An evolutionary biogeographical analysis may involve five steps: (1) recognition of biotic components (sets of spatio-temporally integrated taxa due to common history), through panbiogeography and methods used to identify areas of endemism; (2) contrastation of the biotic components and identification of the vicariant events that fragmented them, through cladistic biogeography and comparative phylogeography; (3) establishment of a hierarchic arrangement of the components in a biogeographic system of realms, regions, dominions, provinces and districts; (4) identification of cenocrons (sets of taxa with similar origins and ages), dated using intraspecific phylogeography, molecular clocks and fossils; and (5) formulation of a geobiotic scenario, that explains the evolution of the biotic components and cenocrons, integrating geological and tectonical information. © 2008 Sociedad de Biología de Chile.