Buying Time

Abstract

What is life? How can life, which is highly organized, arise spontaneously and persist in an entropic universe, where order naturally decays to disorder? This was a major puzzle for twentieth-century chemists and physicists who eventually identified two phenomena, autocatalysis and open thermodynamic systems, as key to understanding this conundrum. Life uses metabolism (autocatalytic reactions) to bring high-grade energy into the system, which it stores and degrades to do work in the system, and then exports back out of the system to the surroundings as heat and other forms of low-grade energy. Metabolism is how organisms exploit their surroundings, creating a sense of Circular Time. This “buys” living systems the time to be “alive,” but to what end? The goal that Darwin identified is indefinite persistence, which life achieves through its inheritance systems. The essence of inheritance is the storage and transmission of information that can be passed on to offspring in a way that specifies the development of a new organism, including the metabolic system. Inheritance allows organisms to explore their surroundings, creating a sense of Linear Time through the irreversible processes (growth, ontogeny, reproduction, evolution, speciation) that produce a distinction between past and future. To persist indefinitely, life needs to be evolvable, and this requires constantly exploiting—through metabolism and the production of Circular Time—without losing the ability to explore—through inheritance and the production of Linear Time. The Nature of the Organism is life as a combined metabolic-inheritance system that becomes embedded in its own time; therefore, any unified theory of evolvable life requires integrating the two.