Many animals can. There are a gene for it, humans don't have it. There is a lot of speculation as to why, but nothing really stands out (possibly just random chance - if you eat enough there is no advantage to keeping the gene and in turn no loss from losing it. However I'm unable to rule out other possibilities) https://pmc.ncbi.nlm.nih.gov/articles/PMC3145266/ is a really interesting survey of the issue across many different species.
From the article:
> Another argument supporting the suggestion that species which have lost their GLO gene were under no selective pressure to keep it, is that all species which have lost their GLO gene have very different diets but all of them have diets rich in vitamin C
What would a diet poor in vitamin C be considering that "everything else" makes it? I guess root vegetables? It feels like, if anything, this would imply a GLO gene decay more often than has happened, no?
That is probably a question for a nutritionist not me. My understanding is Grains, root vegetables, and meat are all low in vitamin C. Likely other things as well. But I'm not a nutritionist (I've read enough that I think I'm right here, but not enough to state it with confidence), so take the above with plenty of salt.
