Conceptual Challenges for Contemporary Theories of the Origin(s) of Life

Contemporary theories of the origin of life divide along the same conceptual lines as contemporary accounts of the nature of life, with small molecule theories (e.g., Wachtershauser’s iron pyrite world) corresponding to metabolic theories/definitions of life and genes-first theories (currently dominated by the RNA world) corresponding to evolutionary (e.g., chemical Darwinian) theories/ definitions of life. I discuss some difficulties faced by this general approach: First, it isn’t at all obvious that a successful theory of the origin of life will divide along the same lines as a theory of the nature of life. Second, in both cases there is the worry that signs of life are being mistakenly treated as essential to life. Third, most theories of the origin of life tend to minimize or even side step the transition from nonliving ensembles of molecules to the first proto-organisms. I close with a suggestion for dealing with some of these difficult problems.