Convergent changes in muscle metabolism depend on duration of high-altitude ancestry across Andean waterfowl

High-altitude environments require that animals meet the metabolic O₂ demands for locomotion and thermogenesis in O₂-thin air, but the degree to which convergent metabolic changes have arisen across independent high-altitude lineages or the speed at which such changes arise is unclear. We examined seven high-altitude waterfowl that have inhabited the Andes (3812-4806 m elevation) over varying evolutionary time scales, to elucidate changes in …