The imitation game—a computational chemical approach to recognizing life

Abstract

The definition of 'life' has invoked innumerable vigorous discussions, ranging from the religious to the scientific, philosophical and metaphysical, and still today no universally acceptable definition is available. This controversy is inescapable because of the absence of a theory of the nature of living systems. There is, however, an urgent practical need for a universally acceptable way of recognizing life or the potential for life. The absence of any agreed- upon guiding definitions of what it is to be alive, and more generally of what is life, makes it difficult for researchers in a variety of communities to objectively recognize success. For example, it remains far from trivial within the exobiology and astrobiology communities to objectively assess whether a new form of extraterrestrial life has been discovered; for researchers studying the origins of life, it is difficult to demonstrate whether life's beginnings have been successfully explained; and in the synthetic biology and artificial chemistry communities, demonstrating the creation of a wholly synthetic life form is a daunting process.