Here's the full text of the "On the origins of cells..." paper via sci-hub: https://sci-hub.se/10.1098/rstb.2002.1183 https://sci-hub.se/10.1098/rstb.2002.1183

Here's the full text of the "On the origins of cells..." paper via sci-hub: https://sci-hub.se/10.1098/rstb.2002.1183 https://sci-hub.se/10.1098/rstb.2002.1183 There's nothing in it about ultraviolet splitting of water or oceanic oxidation. If Nick Lane meant to paraphrase the paper in that cited passage, he did a poor job. Direct UV homolysis of water to release hydrogen requires a photon with more than 6.5 electron volts of energy [1], corresponding to a wavelength of 190 nm or shorter. As you can see here, solar irradiance is extremely low at wavelengths shorter than 240 nm: https://en.wikipedia.org/wiki/Solar_irradiance#/media/File:Solar_spectrum_en.svg https://en.wikipedia.org/wiki/Solar_irradiance#/media/File:S... There isn't enough energetic UV radiation emitted from the sun to directly oxygenate the Earth via water homolysis. It might be possible for an exoplanet in orbit around a hotter star that emits more energetic UV. EDIT: I forgot to account that the sun may have had a very different UV profile billions of years ago. "UV radiation from the young Sun and oxygen and ozone levels in the prebiological palaeoatmosphere" https://sci-hub.se/10.1038/296816a0 https://sci-hub.se/10.1038/296816a0 UV measurements of young T-Tauri stars, resembling the Sun at an age of a few million years, have recently been made with the International Ultraviolet Explorer. They indicate that young stars emit up to 10^4 times more UV than the present Sun. [1] https://en.wikipedia.org/wiki/Photocatalytic_water_splitting#Concepts https://en.wikipedia.org/wiki/Photocatalytic_water_splitting...