One fundamental question in the field of the Origin of Life is how the first molecules of DNA replicated and evolved on the primordial Earth, more than 4 billion years ago. Before the emergence of the first cells or any other form of compartmentalization, DNA and RNA molecules were likely dissolved into water ponds or into pores of rock filled with water and gas: ubiquitous conditions on a volcanic Earth. The high volcanic activity and the high temperatures were responsible for an atmosphere extremely rich in CO2. The concentration of carbon dioxide was about 25,000 times higher than today.