The Case for Prebiotic Chemistry During the Hadean Eon

Geochemists disagree whether or not prebiotic chemistry has existed already during the Hadean Eon and whether the then terrestrial atmosphere has been strongly or weakly reduced. Here I argue that cellular life has existed already just after the end of the Hadean Eon and that terrestrial life has survived a number of cataclysms during the Earth's history. I argue that although organic molecules have been detected in meteorites that most organic molecules required for the formation of macromolecules must have been formed on Earth. Finally, I argue that the primitive terrestrial atmosphere during the Hadean Eon has been weakly reduced, so that amino acids and small nucleic acids could have been formed. I suggest that the first self-replicable macromolecules have been similar to viroids.