The origin of life: the first self-replicating molecules were nucleotides

Difficulties to synthesize RNA nucleotides from their subunits in modern labs under simulated environments leads us to propose a possible process for the synthesis by cross complimentary self-replication with help of clay minerals, which might be operated on prebiotic Earth. Clay minerals are known to be good catalysts and certainly existed on prebiotic Earth. The self-replication of RNA nucleotides (monomers) may be considered as the origin of potential self-replication of some extant RNA polymers, and also the reason for homochirality of RNA molecules.