RNA World Hypothesis
... Orgel’s RNA- World Hypothesis For centuries the origin of life has been in question. ... ” Orgel believes in the theory of an RNA- world, “a world in which RNA catalyzed all the reactions necessary for a precursor of life’s last common ancestor to survive and replicate.” In the 1960’s, this theory was arrived at independently by Orgel, Woese, and the infamous Francis Crick who had previously with James Watson mapped the DNA structure and uncovered the base pairing in both RNA and DNA. In his paper Orgel discusses the historical research and experiments done regarding the origin of life, the problems with the RNA - world hypothesis and some alternate scientific theories. ... With this information and his own experimentation Orgel went on to propose the RNA world. ... Knowing this information the question turned to RNA, DNA or Proteins. RNA was chosen as the most likely because of its ability to replicate itself, the fact that ribonucleotides are more easily synthesized (ribose) and it was more likely that DNA came from RNA. Next, it is believed that RNA would have behaved differently in the early atmosphere in order to act without proteins, therefore, it would have had “the capacity to replicate without proteins and catalyze every step of protein synthesis.” In 1983 Cech and Altman independently uncovered an RNA enzyme call Ribozyme, hinting that RNA may have once been catalytic.