Life in the planet’s latitudinal and altitudinal margins has long weathered extremes: Tibetan wild yaks, Arctic muskoxen, Bhutanese takin (“gnu goats”), or the Gobi’s saiga gazelles became inured to dryness, thin air and cold. Now rampant climate change together with hunters, poachers, herders and predators (which increasingly include feral dogs) is driving these “elusive, dazzling treasures” to the brink. In refreshingly footnote-free dispatches, the conservation biologist Joel Berger discusses the Pleistocene ancestry of these ungulates — physical and behavioral traits that may yet allow social slow-breeders to adapt. In spite of a “disquieting desperation” pervading the no-longer-so-icy barrens, Berger finds grace notes of…