RNA AND THE `RNA WORLD POSTULATE HAVE BECOME A MAIN STAY OF MANY SCENARIOS PUT FORWARD TO EXPLAIN THE ORIGIN OF LIFE IN THE CONTEXT OF CHEMICAL EVOLUTION. HOWEVER, THE CHEMICAL EVENTS THAT LED TO THE EMERGENCE OF RNA, AND THE SELF-ASSEMBLY OF RNA VIA POTENTIALLY NATURAL PATHWAYS, IS STILL UNCLEAR. A `PRE-RNA WORLD CONCEPT HAS BEEN CONSIDERED WHEREIN AN ANCESTOR (OR ANCESTORS) OF RNA, WHICH IS (ARE) EASIER TO ASSEMBLE FROM PREBIOTIC COMPONENTS, WOULD HAVE ENABLED THE APPEARANCE OF RNA. HOWEVER, THE INTRODUCTION OF AN `ANCESTOR OF RNA BRINGS ADDITIONAL COMPLICATIONS: FOR EXAMPLE, HOW A `PRE-RNA WORLD TRANSITIONED TO AN `RNA WORLD: (A) DID THE `PRE-RNA WORLD HAVE ITS OWN PROTO-PREBIOTIC CHEMISTRY WITH ITS OWN GENOTYPE AND PHENOTYPE? (B) HOW MUCH OF THESE PROCESSES COULD BE (WERE) PORTED OVER TO THE `RNA WORLD ? (C) OR DID THE `RNA WORLD HAVE TO DEVELOP ALL OF ITS, GENEOTYPE, PHENOTYPE AND ITS ASSOCIATED PROCESSES, 'DE NOVO INDEPENDENT OF THE PREVIOUSLY DEVELOPED SYSTEMS CHEMISTRY? MORE IMPORTANTLY, A CLEAN TRANSITION FROM A HOMOGENEOUS PRE-RNA WORLD TO A HOMOGENEOUS RNA WORLD (AKIN TO A RNA WORLD TO A DNA-RNA-PROTEIN WORLD TRANSITION) WOULD HAVE BEEN HIGHLY UNLIKELY UNLESS THERE WERE SOPHISTICATED MECHANISMS TO SEPARATE THEIR CHEMISTRIES. MORE OFTEN THAN NOT, IT MAY HAVE BEEN MORE OF MIXTURE OF (HETEROGENEOUS) SYSTEMS, THEIR CHEMISTRIES AND THE INTERACTION BETWEEN THEM THAT WOULD HAVE DICTATED THE PATH OF CHEMICAL EVOLUTION. FURTHER SELECTION PRESSURES, SUCH AS STABILITY (TOWARDS HYDROLYSIS AND DECOMPOSITION) AND THE ABILITY TO FORM COMPLEX STRUCTURES (CONFERRING THE ABILITY TO REPLICATE, ACT AS A CATALYST AND SELECTIVELY BIND TO SMALL MOLECULES) WOULD HAVE FINE-TUNED THE MIXTURE TOWARDS HOMOGENEITY. ONCE A HOMOGENEOUS SYSTEM CAME TO DOMINATE, IT COULD HAVE RECRUITED THE NECESSARY PARTNERS AND EVOLVED THE CHEMISTRY NEEDED TO SELF-SUSTAIN AND PROPAGATE ITSELF. THE PROPOSAL AIMS TO TACKLE THE QUESTION OF A `PRE-RNA WORLD FROM A GRADUAL CHEMICAL EVOLUTION VIEW-POINT BY POSTULATING THAT THERE NEED NOT HAVE BEEN A CLEAN TRANSITION FROM ONE HOMOGENEOUS SYSTEM TO ANOTHER HOMOGENEOUS SYSTEM, BUT RATHER A COMBINATORIAL MIXING-IN AND MUTATION OF INDIVIDUAL CHEMICAL-STRUCTURAL ELEMENTS RESULTING IN A PROGRESSIVE EVOLUTION THAT LED TO RNA. IN THIS SCENARIO RNA WOULD HAVE BEEN A PRODUCT OF INCREMENTAL CONSTITUTIONAL REPLACEMENT OF THE PREVIOUS SYSTEM(S) RATHER THAN A REPLACEMENT OF THE SYSTEM(S) AS A WHOLE. THIS IMPLIES THAT THE PREVIOUS SYSTEM(S) NEED NOT BE HOMOGENEOUS; RATHER, THIS ALLOWS FOR THE ANCESTORS OF RNA TO BE A HETEROGENEOUS MIXTURE OF BACKBONES, RECOGNITION ELEMENTS AND LINKERS, OR AN ENTIRELY DIFFERENT PARADIGM OF TRANSITION. THE UNDERLYING ASSUMPTION IS THAT THE SAME TYPE OF (ABIOTIC) CHEMISTRY THAT GAVE RISE TO RNA BUILDING BLOCKS, WOULD HAVE ALSO OPERATED ON POTENTIAL ALTERNATIVES AND PRODUCE ALTERNATIVE BUILDING BLOCKS (BACKBONE AND RECOGNITION ELEMENTS) THAT WOULD HAVE BEEN AVAILABLE FOR FURTHER PROCESSING. EMERGENCE OF RNA WOULD HAVE RESULTED FROM A PROCESS OF GRADUAL CHEMICAL EVOLUTION, AS THE RESULT OF AN OPTIMIZATION OF STRUCTURE-FUNCTION RELATIONSHIP.