Extending the concept of kinetic stability: Toward a paradigm for life

The physico-chemical relationship between living and non-living systems remains a question of intense debate. This paper introduces the concept of dynamic kinetic stability as a means of incorporating living systems within a conventional physico-chemical framework. Its essence, all replicating systems, both animate and inanimate, represent elements of a replicator space. In contrast to the world of non-replicating systems (all inanimate), where selection is fundamentally thermodynamic, selection within replicator space is effectively kinetic. Driven by mutagenic autocatalysis selection in replicator space leads from kinetically less stable systems to kinetically more stable systems. Our kinetic approach suggests that all living systems may be thought of as manifesting a kinetic state of matter (as opposed to the traditional thermodynamic states), and allows the translation of key Darwinian concepts, such as fitness and natural selection, into traditional physico-chemical terms that are applicable at the molecular level.