Historical biogeography applied to the distribution of Mexican plants

Biogeographical patterns of the Mexican flora are explained based on 3 different theories, considering number of species, endemisms, and relations among areas: 1) dispersalist theory, where Mexico has been considered as the receiver of elements of different sources or geographic areas, considering that it is located in the transition zone between the Nearctic and Neotropical regions, which along the autochthonous ones form a complex mixture of species with different origins, both spatial and temporal, 2) vicariant theory, that proposes a close relationship between the earth's history and the history of the biota, so that the number of species and their distribution may be explained by the complex geologic history of Mexico, and 3) pleistocenic glaciations, which explain the recent distributional patterns of plants based on ecological and historical arguments, based on paleoclimatic changes of the recent past. A continuous debate within historical biogeography has high lighted the importance of biogeography as source of evidence for taxonomy and vice versa. Historical biogeography has a close relationship with systematics, but is an independent discipline within comparative biology. Biogeography is undergoing a conceptual revolution that is causing a revision of its fundamentals and methods. The utilization of different methods in an integrative manner in the same analysis may maximize the advantages of each one