Abstract
This is the concluding article in this series on origin of lifetheories. Earlier articles in the series may be found in , January1976, and The second article of this series included a discussion of Fox's scheme, or thermal model, for overcoming the thermodynamic barrier to the formation of proteins (amino acid polymers), and a discussion of other polymerization schemes. It was pointed out that Fox's thermal model involves a series of conditions and events, most of which would have had such a vanishingly low order of probability on any plausible primitive earth, that the overall probability of protenoid microspheres arising through natural processes would have been nil. It was further pointed out that, in any case, the polymers produced by such a postulated process would have consisted of randomly arranged amino acids with no significant biological activity and thus Fox's model has no relevance to the origin of living systems.