▪ Abstract Any understanding of contemporary biodiversity change in the Americas is likely to be uninformative and misleading if it employs a prehistoric baseline imbued with pristine characteristics. Archaeological evidence clearly displays a protracted history of environmental transformations at varying geographical and temporal scales throughout the Holocene (that is, the past 10,000 years). Because of problems inherent to the interpretation of the archaeological record, the genesis of these transformations often can only be ambiguously attributed to environmental and/or anthropogenic origins. However, at any given time or place, both the distribution of the numbers of different kinds of organisms and their relative abundances were in a constant state of flux since the retreat of glacial cover some 10,000 years ago. Here I review archaeological evidence to illustrate the dynamism of prehistoric biodiversity, which can be attributed to environmental events, to anthropogenic causation, or as a response of these to each other.