As a genre preoccupied with the possible, science fiction has long engaged with the consequences and impact of evolution. Yet whilst phrases such as ‘the next phase of human evolution’ abound in a great many works, ‘evolution’ is often in fact, code for degeneration and devolution. This tendency is particularly pronounced at the end of the 20th and early 21st centuries, when millennial tensions and increasing concerns about the nature of the human gave rise to a series of works which utilize evolution as a mechanism through which to examine a dystopian future for the species. For some writers and film-makers, the very mechanism of selection which made us human became the vehicle of the eventual reversion of our descendants to a state of lessthan-humanness — a return to the human as beast. This paper will explore this trend by examining four works between the period 1985 and 2015 (Kurt Vonnegut’s 1985 Galápagos, Dougal Dixon’s 1990 Man after Man, Stephen Baxter’s 2002 Evolution, and the 2006 Mike Judge’s movie  Idiocracy), each of which posit bleak futures for a species fated to return to the very state of nature it takes pride in setting itself apart from.