Resumen en español

Historical biogeography in essence is the study of the geographic distribution of organisms in terms of their evolutionary history. Studying the relationship between geographic space and species diversity provides an important tool to understand at least in part the speciation process, especially in very diverse and widely distributed groups, such as the species of the genus Craugastor; which, not only present particular characteristics of life history, but also of evolutionary history. This introduces great tension when trying to understand how the northsouth recolonization events occurred above oceanic waters. The group of species Craugastor fitzingeri, which includes eight species distributed from northern Central America to northern South America, is of Central American origin; Therefore, six hypotheses related to the biogeographic history of this species (I,II,III,IV), a phylogeographic analysis (V) and environmental comparisons of the niche of said species (VI) were tested. To analyze the phylogenetic relationships and the divergence times of the species of the group, a phylogeny was carried out under Bayesian inference with estimated divergence times. In order to identify the most important events in the diversification of the east and its relationship with the geological and/or biogeographical history of the continent, a ancestral ranges reconstruction was carried out using the S-DIVA method, and the biogeographical regions established by Morrone (2014). Once these two points were analyzed, different paraphyletic groups were observed eventhough the C. fitzingeri clade was monophyletic (Pp=1); therefore, C. longirostris was taken as a case study to review how much molecular variation could be recorded in a widely distributed species. For this, the calculation of genetic distances (Tamura-Nei), a phylogenetic tree under Bayesian inference for the species and an analysis of genetic structure (Fst) were performed. Finally, the environmental niches of the species of the group were compared, using a niche equ ivalence test and a niche similarity test. Hypotheses I and II were fulfilled, since the dispersion was the most important event to explain the diversification of the group, in addition to having correspondence with the geological events of the continent. The phylogenetic relationships of the group were not very clear, but three independent lineages could be distinguished in the Colombian Chocó for C. longirostris, so it is possible that adaptations are taking place at the local level. The Fst values were close to 1, thus confirming that a case of directional selection may be occurring, at least for the Colombian C. longirostris populations. The comparisons in the environmental space, although they were not conclusive, allow us to infer that ecological 10 studies should not be separated from the genetic processes and the phylogeographic patterns of the species. It is also recommended to include more genetic information that covers a greater range of distribution for each species, added to a greater diversity of genes.