Fatores ecológicos e evolutivos na organização da diversidade genética de aves no interflúvio Purus-Madeira, Amazônia Ocidental

Abstract

Phylogeographic studies of Amazonian birds have revealed large intraspecific diversity, even within recognized areas of endemism. To understand the origin and organization of Amazonian diversity, including the influence of recent history and current landscape, we need to evaluate fine scale patterns of genetic diversity in relation to detailed environmental information. We studied phylogeography and demographic history of two understory bird species, Gymnopithys salvini and Lepidothrix coronata, from the Purus-Madeira interfluvium, within the Inambari area of endemism using mtDNA and nuclear markers with dense sampling. The Purus River was found to be a geographic barrier for both species. Both species showed signs of recent population expansion and had no genetic structure within the interfluvium, which includes two distinct vegetaion types and geological formations. This result is probably due to a dynamic geological history and recent occupation of the landscape by current populations, suggesting that biogeographic history is a better predictor of the pattern of bird genetic diversity within the Purus-Madeira interfluvium than the current environmental heterogeneity. We also show further evidence for the need to evaluate the existence of independent evolutionary lineages of understory upland forest birds within traditionally defined areas of endemism in Amazonia.