Comparative phylogeography of three species of orchid bees (Apidae: Euglossini) with cross-Andean distributions

• Ano de defesa: 2018
• Autor(a) principal: Arango, Stephania Sandoval
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertacoes da USP; Universidade de São Paulo; Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto
• Palavras-chave em Português: Andes; Biogeografia; Padrão; Genética; Neotropical; Hymenoptera; Neotropics; Genetics; Biogeography; Pattern
• Link de acesso: https://teses.usp.br/teses/disponiveis/59/59131/tde-17042026-112731/

The uplift of the Andes is considered highly important for the processes of speciation and diversification in the Neotropics, because this event has led to dramatic changes in the geography and climate of South America. The formation of the Cordillera is associated with a split in the distribution of organisms of the region, resulting in geographic vicariance and, consequently, to genetic isolation between populations on lowland forests. Some Neotropical species, nonetheless, have cross-Andean distributions, suggesting recent dispersion through the Cordillera. Among widespread species, orchid bees (Apidae: Euglossini) are likely candidates for recent cross-Andean dispersion, as approximately 25% of the species have cross-Andean distributions. The objective of this research was to assess the patterns and phylogeographic congruence of three species of orchid bees with cross-Andean distributions in the northern Andes, and which its relationship with the final uplift of the Andean Cordillera. Samples of Euglossa ignita, Eulaema meriana, and Exaerete smaragdina were collected along the flanking regions of the northern Andes and through the inter-Andean valleys to see if genetic variation was concordant with those regions. Phylogeographic structure was assessed using one mitochondrial and one nuclear marker, performing Bayesian inference and population genetics analyses. We found geographic genetic structure in Eg. ignita, with one lineage in the Chocó biogeographic region and another in the Amazon region, diverging at ~2 Mya. The result suggests a dispersal event after the final uplift of the northern Andes as a likely explanation for the cross-Andean genetic differentiation. For El. meriana, it was not identified a geographic structure according to the defined regions, but a differentiated population in the inter-Andean dry tropical forest was recognized, probably representing a more recent colonization. Finally, for Ex. smaragdina two lineages at each side of the Andes were identified, but with subsequent colonization of the other side. The initial separation of those Exaerete lineages appears to be congruent with the final uplift of the northern Andes. No common phylogeographical pattern was found for these three Neotropical species and their different histories appear to be due to differences in the physiological tolerance of each and their ancestral areas.