60 years ago origin of life (OOL) researches practically wet themselves with excitement over Miller-Urey. Now everyone knows Miller-Urey, while perhaps mildly interesting, had nothing to do with OOL, because the early earth’s atmosphere was weakly reducing and the M-U reaction simply does not occur in such an atmosphere.
No worries. We get this from a new Proceedings of the National Academy of Science paper:
As to the sources of nucleobases, early Earth’s atmosphere was likely dominated by CO2, N2, SO2, and H2O. In such a weakly reducing atmosphere, Miller–Urey-type reactions are not very efficient at producing organics. One solution is that the nucleobases were delivered by interplanetary dust particles (IDPs) and meteorites.
This is amusing. You can’t get nucleobases from known natural sources? Just invoke space particles and meteorites. This is just one step removed from “little green men did it.”