Social Studies of Science 2014, Vol. 44(2) 165–193 © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0306312713505003 sss.sagepub.com The perils and promises of microbial abundance: Novel natures and model ecosystems, from artisanal cheese to alien seas Heather Paxson and Stefan Helmreich Anthropology, Massachusetts Institute of Technology, Cambridge, MA, USA Abstract Microbial life has been much in the news. From outbreaks of Escherichia coli to discussions of the benefits of raw and fermented foods to recent reports of life forms capable of living in extreme environments, the modest microbe has become a figure for thinking through the presents and possible futures of nature, writ large as well as small. Noting that dominant representations of microbial life have shifted from an idiom of peril to one of promise, we argue that microbes – especially when thriving as microbial communities – are being upheld as model ecosystems in a prescriptive sense, as tokens of how organisms and human ecological relations with them could, should, or might be. We do so in reference to two case studies: the regulatory politics of artisanal cheese and the speculative research of astrobiology. To think of and with microbial communities as model ecosystems offers a corrective to the scientific determinisms we detect in some recent calls to attend to the materiality of scientific objects. Keywords materiality, microbes, model ecosystems Corresponding author: Heather Paxson, Anthropology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307, USA. Email: paxson@mit.edu 505003SSS 44 2 10.1177/0306312713505003Social Studies of SciencePaxson and Helmreich research-article 2013 Article at Massachusetts Institute of Technology on March 11, 2014 sss.sagepub.com Downloaded from