Are you able to survive on a a raw vegan diet without taking supplements? If not then the raw vegan diet would be unsustainable in the evolutionary process.
We know that B12 comes from animals, however Vitamin B12 comes from bacteria in soil, so in theory as long as a raw vegan eat plenty of dirt they'd be fine.
The other question I have is why are so many raw vegans so defensive? My conclusion is they have built a life around what they eat and not who they are.