From the moment Charles Darwin proposed Africa as the site of human origins, scientists and the lay public alike labored to reconcile contemporary racial hierarchies with the possibility of a universal African birthplace. Previous historical treatments of this phenomenon have focused on the search for the “missing link” in Asia and Europe, an investigation that, if successful, would have effectively established a separate ancestry for the white races. This essay identifies a new component of this history: the racialization of higher-order primates within the nascent discipline of primatology and within US popular culture between the 1910s and 1930s. Departing from Donna Haraway’s originary work on the field, this essay argues that primatology was in fact built upon preexisting scientific racial ideologies, such that the animals themselves became parsed according to racial categorizations. In particular, the anthropomorphization and “whitening” of the chimpanzee on the one hand, and the bestialization and “blackening” of the gorilla on the other, provided a forum for ideas about biological essentialism, evolutionary capabilities, and racial difference. This alternative history is revealed through an examination of the photographic archives and written work of longtime eugenicist and founding primatologist Robert Mearns Yerkes, and through a contextualization of these documents within contemporary scientific and popular cultures. By tracing the lineage of American primatology to the closing arc of eugenic science, this essay seeks to enrich and reimagine the relationship between practices of racialization and speciation within the larger histories of evolutionary thought and racial formation.