2010/12/01 by Steven A. Benner · 1 citation
Physics and Astronomy · #Origins and Evolution of Life #Space Science and Extraterrestrial Life #Planetary Science and Exploration
paper · doi:10.1089/ast.2010.0524
openalex publication_date 2010/12/01 · openalex created_date 2022/05/12 · openalex updated_date 2026/08/02
Any definition is intricately connected to a theory that gives it meaning. Accordingly, this article discusses various definitions of life held in the astrobiology community by considering their connected "theories of life." These include certain "list" definitions and a popular definition that holds that life is a "self-sustaining chemical system capable of Darwinian evolution." We then act as "anthropologists," studying what scientists do to determine which definition-theories of life they constructively hold as they design missions to seek non-terran life. We also look at how constructive beliefs about biosignatures change as observational data accumulate. And we consider how a definition centered on Darwinian evolution might itself be forced to change as supra-Darwinian species emerge, including in our descendents, and consider the chances of our encountering supra-Darwinian species in our exploration of the Cosmos. Last, we ask what chemical structures might support Darwinian evolution universally; these structures might be universal biosignatures.