Bird illustrations from HBW Alive
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I am particularly fascinated with the incredible avian diversity found in the most biodiverse region of the planet, the continental Neotropics. Many hypotheses on why south American birds might exhibit high phenotypic divergence have been proposed (e.g. niche specialization, sexual selection, competition, etc.), yet only a few studies have actually addressed patterns of avian trait evolution in the region.
Geographic barriers (e.g. rivers or mountains) are known to play an important role driving speciation in taxa with limited dispersal abilities in the Amazon basin. Although many Amazonian sister species are highly differentiated genetically, their phenotypes are usually similar. In contrast, many closely-related Andean birds have very different phenotypes, presumably as a result of strong ecological pressures found at different elevational zones of the Andes. Thus, I am interested in disentangling the mechanisms that likely drive trait differentiation and speciation at macro scale in the region. |
Museum specimens are valuable tools for addressing macroevolutionary questions of phenotypic evolution (morphology and plumage coloration) and historical range occupancy. Perhaps the most complete taxonomic group with available specimen collections for research purposes is birds. Standard morphological measurements are widely used in analysis of trait differentiation in this group and I have personally used them on my own research (see Luzuriaga-Aveiga and Weir 2019). For instance, I found that bill depth in closely-related species of suboscine birds occupying similar elevational mid-point ranges evolves faster than oscines along the Amazon to Andes transition. It's now known that the position of a bird in the avian morphospace is a good predictor of its trophic niche occupancy. |
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Bird illustrations from HBW Alive; sonograms from xeno-canto.com
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Avian songs are not only beautiful (in most cases) but also quite intriguing. This behavioural trait evolves differently according to the clade. Songs of suboscine species are genetically inherited and songs of what we call songbirds (oscines) are learned culturally. This latter group of birds even exhibit dialects among populations. |
I am interested in investigating the molecular evolution of distinctive adaptations to high elevations in Andean birds. Species living at highlands are exposed to extreme environmental conditions, such as cold temperatures, high levels of UV light exposure and hypoxia. Therefore, species that colonized these environments must have evolved differentiated physiological adaptations to species living in the Amazonian lowlands. In my research, I seek for patterns of convergent evolution of both mitochondrial and nuclear genes among Andean birds. |
Bird illustrations from HBW Alive
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