Origins of life: Concepts, data, and debates

D ebates on the origin of life—or more precisely the terrestrial origin of life—as well as the origin of the universe are followed with great interest in almost all human societies. In the latter case, there exists a standard model, the big bang theory derived from an extrapolation of elementary particle physics to the birth of our universe. Nothing comparable is at hand for origin of life studies. Many different ideas are competing and none is available to provide a sufficiently plausible root to the first living organisms. It is even not clear what is meant by ‘life’ and possible definitions are heavily debated. What will be pointed out in this essay concerns two issues: First, no definition of life is needed for work on early or chemical evolution, and second, new approaches are required, and borrowing ideas from handling complex systems might be useful. A list of criteria to be used in the classification of prelife and life could, for example, contain: