In this essay, I argue that the recurring themes of perception and the place of the human in the scale of geological time came together for Charles Darwin first in an anthropological context aboard HMS Beagle in the 1830s. Though his primary interests in his early research years were geology and zoology, the foundational influence of the Beagle journey on his burgeoning theories of the human is not to be discounted. I contend that it was Darwin’s few but important anthropological observations during this significant 1831-36 excursion, especially of the native inhabitants of Tierra del Fuego, that left the most indelible impression on the young naturalist, and to which he would anxiously return in subsequent years. This is where he puzzled over the seemingly single-generation shift between the three pleasant, Anglicized Fuegians (who, after a three-year British sojourn, traveled back to Tierra del Fuego aboard the Beagle with him) and their “savage” brethren who greeted the ship on the shores of their native homeland. I begin my essay by tracing the foundational influence of language in shaping Darwin’s re-vision of the human, as his prose often shifts between the perceptual immersion of the curious naturalist and the ordered prose of a calculating scientist. I then examine Darwin’s actual experience with the Anglicized Fuegians, and his perplexity at their eventual “reversion.” This is the moment, I argue, when Darwin’s theory and gaze begin to focus on the human. Through his exposure to the Anglicized Fuegians and their unassimilated counterparts at home, coupled with the “new way of seeing” and writing that his landscape and experiences demanded, Darwin inaugurates a burgeoning concept of cultural relativity and cultural fluidity, one that eventually enables him—and paves the way for future scholars and practitioners—to link all humans “along the arc of culture.”