On the nature of naturalness? Theorizing 'nature' for the study of public perceptions of novel genomic technologies in agriculture and conservation

Notions of naturalness are widely assumed to drive how people perceive genetic engineering (GE). As newer forms of genetic engineering-namely, gene editing, gene drives, and synthetic biology-are reshaping life forms in both agriculture and conservation, they are increasingly raising questions of what a 'natural' food, organism or ecosystem is, and whether objections toward 'unnaturalness' or preferences for 'naturalness' might reveal a deeper ethical or value-based logic. A number of fields have sought, both directly and indirectly, to define the concept, but insights have not yet been applied to new forms of genetic engineering. This paper proposes that systematically reviewing scholarly interpretations of 'naturalness' might offer weight to a concept that is often dismissed as irrational. Here, we review and synthesize insights from a range of fields, outlining possible logics public groups might employ to reason about what is '(un)natural'. We also offer a novel thought experiment in which we apply these logics to a sample of novel GE applications. One of our core findings is that '(un)natu-ralness' may be understood not necessarily as a quality of an object, but rather as a characteristic of ecological, social, cultural, and spiritual relationships. Such an understanding implies the need for ongoing engagement with the values embedded in ideas of naturalness and empirical explorations of how such values inform debates on novel engineered foods, organisms and ecosystems.