internal study: a way of understanding the causes and conditions for a WAC program's origins and reproduction, mutations and adaptations, endangerment, or extinction.Moving from taxonomy to evolutionary theory follows a historical pattern.Evolutionary theory represented the next scientific step beyond taxonomy for advancing our understanding of the natural world.Carl Linnaeus (Carl von Linn), author of Systema Naturae, 1735, is credited with establishing hierarchical structures for classifying organisms according to their physical traits and their methods of reproduction.His taxonomy relied on visible, observable characteristics.In the late eighteenth century, Cuvier's functional taxonomy superseded Linnaeus's descriptive taxonomy (Foucault 268).In contrast to the externally visible traits emphasized in Linnaeus's taxonomy, Cuvier was beginning to theorize internal causes and conditions that could account for differences and disruptions."From Cuvier forward, " Foucault argues, "it is life in its non-perceptible purely functional aspect that provides the basis for the exterior possibility of a classification" (268).Classification is still useful for Cuvier, but he shifts the categories from highly specific traits to very general principles.In his emphasis on function, Cuvier thus helps lay the ground for Charles Darwin's theory that species formation depends on the natural selection of traits that help an organism adapt to its environment and reproduce successfully. 1 Darwin's theory of natural selection relies on environmental conditions, mutations, and change.His famous finches adapted to different environmental niches on the Galapagos, with the most relevant factor being the type of available food.In a different place, adaptive coloration may have led Darwin to study predatory/prey relationships.The point remains: if a particular mutation lines up with an environmental niche and gives an organism a reproductive advantage in terms of a food source, protective coloration, or something else it can productively exploit, that trait gets passed along to subsequent generations and eventually a new species is formed.WAC also speciates by adapting to its local environment.Evolutionary metaphors help explain and explore patterns, interrelationships, and the conditions under which a program can thrive.The metaphor can also help us understand that not all mutations are adaptive or successful, and that certain conditions threaten a program's survival.Evolutionary and ecological metaphors are, of course, not new to WAC discussions or to more general discussions of writing practices.In 1986, Marilyn Cooper argued for "The Ecology of Writing, " where writers are part of a varied and inherently dynamic system.Rather than paying attention to individual writers and their immediate contexts, Cooper asks us to attend to the ways in which, "all the characteristics of any individual writer or piece of writing both determine and are determined by the characteristics of all the other writers and writings in the system" (368).For Cooper, contextual models serve a taxonomic function; she notes, for instance,The WAC Journal 24 (2013).

WRITING ACROSS THE CURRICULUM linkages are generally acknowledged to help students improve as writers and engage more deeply in disciplinary course content. However, the extent to which the literacy skills that are taught in general writing courses transfer to the specific writing needs of a particular discipline remains a debatable issue. Referring to first year writing courses, Amy Devitt notes that writing courses “have been attacked as not useful, in part because of a potential lack of transferability of the general writing skills learned in composition courses to the particular writing tasks students will later confront” ( ). Margaret Mansfield similarly maintains that attempts to reproduce real world writing in the classroom are “intrinsically doomed” ( ), as do many of the essays in Joseph Petraglia’s collection, Reconceiving Writing, Rethinking Writing Instruction, which question the value of what Petraglia terms GWSI (General Writing Skills Instruction). However, an important benefit of a cross curricular model, one that receives little attention in writing across the curriculum scholarship, is that linked courses not only help students improve as writers, but they can also enable students to understand that “when people learn, they don’t take on new knowledge so much as a new identity” (Lindquist ). Identity is closely linked with writing, but WAC tends to focus primarily on the actual writing, not on the role writers play in a discourse community. In this essay, we discuss a successful linkage between a writing class and a class in Health Sciences that used rhetoric, with particular emphasis on the concepts of identity, genre, and performance, to help students gain insight into the role of writing in the field of Public Health and understand what it means to be a Public Health professional. Differences in students’ responses to essays written at the beginning of the semester as