DNA WORLD VS RNA WORLD IN EVOLUTION

It was believed for long time that DNA was at the centre of origin and development of the living system. With the earlier realisation that R NA can act as the genetic material like DNA and later demonstration th at it also acts as catalysts like proteins, the concept of RNA world e volved. Further, several lines of evidence indicated that life might h ave originated based on RNA and RNA world existed before the DNA world . Arguments in favour of the fact that RNA might have acted as the ori ginal genetic material and passed on this ability to DNA during the la ter stage of evolution has been examined with the information already available in the literature and some evidence produced. from this labo ratory based on the functions of ribosomal RNAs. Further, the existenc e of the RNA-protein world (instead of only RNA world) prior to the DN A-protein world of today has been hinted at.