Actually, being a medical student means nothing. You'll spend a matter of hours studying nutrition in your entire 7 years studying your degree. It's as relevant as saying you're a biologist or a mathematician. Unless you're a dietician or something similar, it doesn't make a difference since anyone of any field interested in dietetics and nutrition will have studied in their own time more than any medicine grad will have in their degree.

I'm not sure what your point is about evolution. Ultimately, we can eat a vegan diet and be perfectly healthful, whilst avoiding horrible diseases and seeing benefits, so why not.

Secondly, vegans typically have way more organic foods in their diet when you think about how 99% of meat in the industry is factory farmed, and heavily processed. But even still, I don't see any point.it doesn't matter if ultimately you can everything you need on a vegan diet, which you can.