Original sentence: It has been hypothesized that the earliest life on Earth may have used PNA as a genetic material due to its extreme robustness, simpler formation and possible spontaneous polymerization at 100°C (while water at standard pressure boils at this temperature, water at high pressure - as in deep ocean - boil at higher temperatures).PNA is not known to occur naturally in modern life forms, but is artificially synthesized and used in some biological research and medical treatments
Edited sentence: It has been hypothesized that the earliest life on Earth may have used PNA as a genetic material due to its higher robustness, simpler formation and possible spontaneous polymerization at 100°C, as compared to DNA or RNA.PNA is not known to occur naturally, but is artificially synthesized and used in some biological research and medical treatments