“…However, genes of functional importance can also be employed to investigate the history of species, particularly when populations are exposed to distinct environments with contrasting selective pressures (Deagle, Jones, Absher, Kingsley, & Reimchen, 2013; Feldman, Brodie, & Pfrender, 2009; Hoekstra, Drumm, & Nachman, 2004; Savage & Zamudio, 2016; Sork et al., 2016). Analyses of functionally important genes allow one to address questions about evolutionary processes such as adaptation and natural selection, complementing inferences of demographic processes based on patterns of geographic variation in neutral genes (Zamudio, Bell, & Mason, 2016). Here, we integrate analyses of neutral markers and protein‐coding genes potentially under selection to test hypotheses about the biogeographic and evolutionary history of a widespread species of duck with a broad latitudinal and elevational distribution in the New World.…”