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Full-Text Articles in Life Sciences

Evolution And Biogeography Of Fire-Eye Antbirds (Genus Pyriglena): Insights From Molecules And Songs, Marcos Maldonado Coelho May 2012

Evolution And Biogeography Of Fire-Eye Antbirds (Genus Pyriglena): Insights From Molecules And Songs, Marcos Maldonado Coelho

Dissertations

The importance of climatic and geologic factors as drivers of population differentiation and speciation in the Neotropical region has long been appreciated. However, many questions remain regarding their roles underlying the processes and patterns of diversification. Studies conducted in distinct regions containing a suite of geological and ecological conditions constitute ideal scenarios to assess the role of Pleistocene climatic changes, rivers, and mountain building as historical diversification mechanisms. In chapters 1 and 2, I used an integrative approach combining molecular phylogenetics, phylogeography and population genetics to elucidate the importance of climatic and geological factors as engines of diversification. I focused …


Pagamea Aubl. (Rubiaceae), From Species To Processes, Building The Bridge, Alberto Vicentini Jul 2007

Pagamea Aubl. (Rubiaceae), From Species To Processes, Building The Bridge, Alberto Vicentini

Dissertations

Species delimitation have a great impact in scientific, environmental and other human activities, and is fundamental for understanding evolution. Plant species are usually delimited based on morphology and rarely species concepts are stated and analysis of variation made explicit. Botanists do see species as ?segments of evolutionary lineages?, but reproductive isolation is rarely addressed. Yet, reproductive isolation is necessary for understanding species, because speciation is the process of acquiring reproductive barriers. Almost any lineage will have species at different stages of isolation, and a single type of data will be insufficient for species delimitation. In plants, other biological processes such …