CHAPTER 7.4 CLAY MINERALS AND THE ORIGIN OF LIFE

Abstract

Bernal first suggested the role of clay minerals in the origin of life because of the ordered arrangement of the clay mineral particles, the large adsorption capacity, shielding against ultraviolet radiation, ability to concentrate organic chemicals and ability to serve as polymerization templates. Clay minerals were proposed as possible genetic material. This appealing hypothesis was not yet supported by experimental data. Many experiments were run to correlate biological one-handedness to clay mineral chemistry but convincing data were not obtained. However, clay minerals act as very efficient catalysts in the polymerization of amino acids and nucleotides, thus supporting the possible existence of an RNA world preceding a cellular world. RNA adsorbed to clay minerals can be encapsulated within vesicles. Once formed, such vesicles could grow by incorporating fatty acids and divide, thus mediating vesicle replication through cycles of growth and division. The data obtained so far suggest that clay minerals played an active role in the abiotic origin of life.