Molecular Evolution to the First Cells†

Abstract

The evolutionary sequence of galactic organic matter ↠ amino acids informational protoprotein ↠ protocell ↠(nucleic acid-governed) contemporary cell is reviewed, and the supporting evidence is presented in outline. The experiments suggest that thermal polymerization of diverse a-amino acids yielded partially-ordered protoproteins which possessed varied proto-enzymic activities. These protoproteins assembled, according to the experiments on simple contact with water to yield protocells. The model protocells contain enzyme-like activities, ultrastructure and selective membranes, and they have been found to reproduce in five modes, each of which is conceptually relatable as an evolutionary precursor to a contemporary mode of reproduction. The processes have been shown to be geologically relevant, imparting much rigour to the model. The simplicity of the formation of the protocellular model and the terrestrial ubiquity of water support the concept of protocells having arisen easily and often as protoprotein formed. These experiments and the derived theory required constructionistic processes based on knowledge obtained by reductionistic methods. © 1973, Walter de Gruyter. All rights reserved.