This thesis considers the understudied issue of genetic engineering as it has been deployed in the literature of the late 20th century. With reference to the concept of the enlightened gender hybridity of Cyborg theory and an eye to ecocritical implications, I read four texts: Joan Slonczewski's 1986 science fiction novel A Door Into Ocean, Octavia Butler's science fiction trilogy Lilith's Brood – originally released between 1987 and 1989 as Xenogenesis – Simon Mawer's 1997 literary novel Mendel's Dwarf, and the first two books in Margaret Atwood's speculative fiction MaddAddam series: 2003's Oryx and Crake and 2009's The Year Of the Flood. I argue that the inclusion of genetic engineering has changed as the technology moves from science fiction to science fact, moving from the fantastic to the mundane. Throughout its recent literary history, genetic engineering has played a role in complicating questions of sexuality, paternity, and the division between nature and culture. It has also come to represent a nexus of potential cultural change, one which stands to fulfill the dramatic hybridity Haraway rhapsodized in her "Cyborg Manifesto" while also containing the potential to disrupt the ecocritical conversation by destroying what we used to understand as nature. Despite their four different takes on the issue, each of the texts I read offers a complex vision of utopian hopes and apocalyptic fears. They agree that, for better or for worse, genetic engineering is forever changing both our world and ourselves.