I thought it was already established that the genes for photosensitivity led to the formation of eyes in all animals. And that the proposed benefit in the early Earth&#x27;s oceans was to keep bacteria from frying themselves if they got too close to the surface (due to there being no ozone layer way back then). So, I&#x27;m not sure if this is all earth shattering knowledge at this point, but it&#x27;s still a fun read.