Is Life a Self-Organized Critical Phenomenon?

Abstract

The step from describing inert matter to describing biological life seems enormous, but maybe it isn’t. Perhaps the same principles that govern the organization of complexity in geophysics also govern the evolution of life on earth. Then nature would not suddenly have to invent a new organizational principle to allow live matter to emerge. It might well be that an observer who was around when life originated would see nothing noteworthy—only a continuous transition (which could be an “avalanche”) from simple chemical reactions to more and more complicated interactions with no sharp transition point indicating the exact moment when life began. Life cannot have started with a chemical substance as complicated as DNA, composed of four different, complicated molecules called nucleotides, connected into a string, and wound up in a double helix. DNA must itself represent a very advanced state of evolution, formed by massively contingent events, in a process usually referred to as pre-biotic evolution. Perhaps the processes in that early period were based on the same principles as biology is today, so the splitting into biotic and prebiotic stages represents just another arbitrary division in a hierarchical chain of processes.