It’s true that we evolved in response to an environment, but the actual genetic changes that allowed for that were not developed with purpose. They happened randomly, and the ones that happened to provide a benefit made those individuals more likely to have more kids that those with less beneficial random changes.

You can find them at the creator’s tumblr. They’ve since stopped making them, though.

Yeah, the cells of most animals have the ability to make their own vitamin C, very likely including our ancestors if you go back far enough. The evolutionary reason why we stopped is probably simply because our bodies stopped needing to make it due to our fruit diet, so individuals that didn’t make the acid had a little bit more energy and nutrients to spare that would’ve otherwise been wasted to make it when it’s not needed. Over millions of years that small difference was enough for them to survive to parenthood slightly more often than their peers, slowly edging them out of the gene pool.

Evolution generally pushes bodies to conserve resources, so unnecessary things are usually dropped if the environment doesn’t require them for long enough. Kinda like how creatures living in dark caves eventually evolve to stop wasting the resources to make eyes and pigmented skin.

Attack on ramen