Fig. 2
From: Non-canonical nucleosides and chemistry of the emergence of life
Natural fluctuations steer chemical transformations towards greater complexity. a Molecular complexity driven by fluctuations of physico-chemical conditions, such as day–night or seasonal changes, leading to wet–dry cycles. b Since the early Earth was not uniform, carbohydrates could have emerged separately from nucleobases or their precursors e.g. via the formose reaction. c When washed into the same environment, different nucleosides/nucleotides could have formed
