Causation and the Origin of Life. Metabolism or Replication First?

Abstract

The conceptual gulf that separates the `metabolism first' and `replication first' mechanisms forthe emergence of life continues to cloud the origin of life debate. In thepresent paper we analyze this aspect of the origin of life problem and offerarguments in favor of the `replication first' school. Utilizing Wicken'stwo-tier approach to causation we argue that a causal connectionbetween replication and metabolism can only be demonstrated if replication wouldhave preceded metabolism. In conjunction with existing empirical evidenceand theoretical reasoning, our analysis concludes that there is no substantiveevidence for a `metabolism first' mechanism for life's emergence, while acoherent case can be made for the `replication first' group of mechanisms.The analysis reaffirms our conviction that life is an extreme expression ofkinetic control, and that the emergence of metabolic pathways can beunderstood by considering life as a manifestation of `replicativechemistry'.