The evolution of RNA is likely to have played an important role in the very early history of life on Earth but it is doubtful that life began with RNA. Consideration of that came before RNA must take into account relevant information from geochemistry, prebiotic chemistry and nucleic acid biochemistry.

The question of life's origins is one of the oldest and most difficult in biology. The answer, if it is ever known, will not be a single statement of fact but rather an extended chronology, beginning with the formation of the Earth and ending with the appearance of cellular organisms. The problem is especially difficult because we have no direct evidence of the events that occurred during roughly the first thousand million years of the Earth's history. The oldest rocks that provide clues to life's distant path are 3.6 x 10⁹ years old and by that time cellular life seems already to have been well established. Modern organisms are so sophisticated that they furnish little information about what life was life before there was a genetic code and a translation apparatus. Extraterrestrial studies have yet to provide us with an alternative life form for comparison. We are left with only a partial understanding of the origins of life that is based largely on inference and conjecture.