Meeting Abstract
The Andes are the world’s highest mountain range, second to those in Asia, which also contain the second highest plateaus, with peaks rising to an elevation of 6,961 m. These Altiplano-plateaus contain wetlands that host a number of waterfowl species, who are ideal for studying the effects of both low oxygen, and cold-stress, due to the metabolic demands associated with their high-altitude environment. This study aims to test for, and compare, the presence of signatures of high-altitude adaptation with respect to variation in the mitochondrial genomes of three Andean waterfowl species: yellow-billed pintail, cinnamon teal and speckled teal. Each lineage has independently colonized the same South American Altiplano wetlands and inter-Andean valley puna grasslands, thus providing natural replicates of independent adaptive events to high-altitude, cold-stressed, hypoxic environments. Here we test whether mitochondrial variation is linked to high-altitude adaptation in these three species, across the full mitochondrial genome. We investigate potential selective pressures at the mitogenome level in three different species of Andean waterfowl across altitudinal populations by analyzing 60 full mitochondrial genomes. In general, there is evidence of convergence at the level of selection acting to maintain the OXPHOS unit’s ability to operate optimally through an increase in purifying selection. This is especially true for the speckled teal, which shows distinct signs of differential selective pressures acting on the mitochondrial genome between high- and low- altitude populations; specifically, a substantial increase in purifying selection likely due to invasion of high-altitude niches.
