Evidence for mtDNA capture in the jacamar Galbula leucogastra/chalcothorax species-complex and insights on the evolution of white-sand ecosystems in the Amazon basin.

Jacamar species occur throughout Amazonia, with most species occupying forested habitats. One species-complex, Galbula leucogastra/chalcothorax, is associated to white sand ecosystems (WSE). Previous studies of WSE bird species recovered shallow genetic structure in mtDNA coupled with signs of gene flow among WSE patches. Here, we characterize diversification of the G. leucogastra/chalcothorax species-complex with dense sampling across its distribution using mitochondrial and genomic (Ultraconserved Elements, UCEs) DNA sequences. We performed concatenated likelihood and Bayesian analysis, as well as a species-tree analysis using ∗BEAST, to establish the phylogenetic relationships among populations. The mtDNA results recovered at least six geographically-structured lineages, with G. chalcothorax embedded within lineages of G. leucogastra. In contrast, both concatenated and species-tree analyses of UCE data recovered G. chalcothorax as sister to all G. leucogastra lineages. We hypothesize that the mitochondrial genome of one of the G. leucogastra lineage (Madeira) was captured into G. chalcothorax in the past. We discuss how WSE evolution and the coevolution of mtDNA and nuclear genes might have played a role in this apparently rare event.