The center of origin of terrestrial mammalian carnivores and their fast body mass evolution associated to long distance dispersal.

Abstract

Fundamental tasks to understand the spatial distribution of biodiversity are to estimate where and when species originated, and how did they disperse over space and throughout new environments, in addition to explaining the evolutionary responses associate d with this geographical movement. However, these estimations have been difficult to obtain because knowing the centers of origin and tracing the historical paths of species at macro scales has always been a hard challenge. Here, using a novel phylogenetic approach that considers the nature processes in a more accurate way at macro scales and the geographical i nformation of both extinct and extant diversity , we 1) estimated the center of origin of all ancestral species of terrestrial mammalian carnivores and their dispersal routes, and 2) evaluate whether the dispersal ability or trans continental dispersals i mplies a fast evolution in body size due the selective pressures of the environment. This doctoral thesis postulates that North America is an important center of origin of early lineages, as the complete clade of mammalian carnivores, the Oxyaenidae and C arnivoramorpha groups , except for Hyaenodonta whose origin was in Europe. North America is the place of origin for the order Carnivora and the subfamilies Feliformia and Caniformia. 350 of the 2632 (13.3%) geographical distances estimated correspond to tr ans continental dispersal events during the biogeographical history of terrestrial mammalian carnivores. Also, the long distance dispersal (LDD) explains the fast evolutionary change found in several independent and mainly recent lineages of terrestrial ma mmalian carnivores and thus their highly discrepant body sizes. Therefore, this thesis means a significant contribution to understanding the origin and distribution of terrestrial mammalian carnivores, achieving the biogeographical relevance of postulating a new center of origin for the complete group and the current order Carnivora, estimating for the first time the geographical distance traveled for all lineages and explain ing how this biogeographical process explain the phenotypical evolution of the group.