Evolutionary literary criticism of a minimalist kind consists in identifying basic, common human needs—survival, sex, and status, for instance—and using those categories to describe the behavior of characters depicted in literary texts. Others pose for themselves a form of criticism involving an overarching interpretive challenge: to construct continuous explanatory sequences linking the highest level of causal evolutionary explanation to the most particular effects in individual works of literature. Within evolutionary biology, the highest level of causal explanation involves adaptation by means of natural selection. Starting from the premise that the human mind has evolved in an adaptive relation to its environment, literary Darwinists undertake to characterize the phenomenal qualities of a literary work (tone, style, theme, and formal organization), locate the work in a cultural context, explain that cultural context as a particular organization of the elements of human nature within a specific set of environmental conditions (including cultural traditions), identify an implied author and an implied reader, examine the responses of actual readers (for instance, other literary critics), describe the socio-cultural, political, and psychological functions the work fulfills, locate those functions in relation to the evolved needs of human nature, and link the work comparatively with other artistic works, using a taxonomy of themes, formal elements, affective elements, and functions derived from a comprehensive model of human nature.