Local adaptation, plasticity, and evolved resistance to hypoxic cold stress in high-altitude deer mice.

) to progressively increasing levels of hypoxia during a simulated ascent to 6000 m, we assessed the relative roles of evolved and plastic changes in thermogenic capacity. At especially severe levels of hypoxia, the superior thermogenic performance of highland natives relative to lowland conspecifics suggests that the broad fundamental niche of deer mice is largely attributable to local adaptation to different elevational zones, including evolved plasticity in gene expression and respiratory traits.