Abstract

Biology is not in principle restricted to life on Earth or to life as we know it, but should be thought of as a universal discipline just as physics and chemistry are, despite the restricted epistemic condition of our N=1 sample. Universal biology seeks generalisations about life considered as a general phenomenon, and is informed by physics and chemistry as well as by biological facts. In this talk I discuss several generalisations that are true of all Earth life and that are plausibly universally true due to universal physical constraints on how life can be and how it can originate. These include, in particular: thermodynamic features of life; cells as the minimum unit of life; the chemical nature of metabolic processes; constraints on the kinds of molecules required for the functioning of living systems; physical limitations on the size and structure of organisms; replication, reproduction, and evolution by natural selection; and universal kinds of ecological relations. The universality of physics and chemistry, and the emergence of order in complex non-living systems, allow us to generate promising hypotheses about life in the universe.