https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3145266/Misremembered on fish apparently lol. But seems has to do with a single gene mutation . And the ability to do so at least theorized in this paper is neutral to survival. Dont tell the makers of airborne, or emergen-c lol.I'm not sure about the mechanism behind vitamin C synthesis, but sometimes a novel gene can be transferred from one population to another by way of a virus. Interesting to think that such a gene could be lost for 1000 years, only to be reintroduced into a totally different population by way of a virus and some transposons.






