Filogenia E Biogegrafia Do Gêneto Turdus (AVES, Turdidae) Com Base Em Sequenciamento Parcial Do Genoma

Abstract

The genus Turdus (Aves: Turdidae) has a cosmopolitan distribution, occurring in the Americas, Africa, Eurasia and Oceania. Previous studies using mitochondrial and nuclear molecular markers had proposed phylogenies and biogeographic hypotheses for this group, although often with little support. It is suggested that the inclusion of Turdus species, missing in these previous studies could alter the conclusions proposed so far. The use of Next Generation Sequencing techniques, and phylogenomic analyses, based on genomic sequences obtained using probes for Ultra Conserved Elements for the genus Turdus (Aves: Turdidae), could elucidate interesting taxonomic and evolutionary issues for the group, as the estimation of phylogenies and biogeographic interpretations of evolutionary history both at the cosmopolitan level and within the American continent. In this work we samples ~70% of the taxa currently recognized for Turdus. In the first chapter, we constructed a species-level phylogeny using more than 2000 loci for Turdus. We estimated the pattern of diversification and evolution of the distribution for this genus of birds. Our results indicate that there have been considerably fewer trans-oceanic dispersals within the genus Turdus than previously suggested, and that the African clade was not involved in the colonization of the Americas. Instead, our findings suggest that dispersal from the Western Palaearctic via the Antilles to the Neotropics might have occurred in a single event, giving rise to the rich Neotropical diversity of Turdus observed today. Our large multilocus dataset, combined with dense species-level sampling and analysed under probabilistic methods, brings important insights into historical biogeography and systematics, even in a scenario of fast and spatially complex diversification. In the second chapter, we attempted to identify factors related to significant changes in speciation rates and to reconstruct the pattern of genetic intraspecific variation for Neotropical species. We used phylogenetic analyzes, a dense sampling of South American species, and comparative phylogenetic analyzes to test whether ecological traits, such as habitat preference, altitudinal range and presence/absence in the Andes influenced the rates of diversification of these birds in this continent. Our results represent a great contribution to the understanding of the phylogenetic relationships within Turdus of South America, which we estimate the radiation during the Late Pliocene and the early-mid Pleistocene. High speciation rates were observed throughout the phylogeny, and a positive correlation was observed in all traits tested, where species associated with forests and lowlands had their speciation rates increased during the radiation in the South American continent.