Someone has probably already said this but I don't evolution as a major threat to immortals. Living things evolve to better suit there environment but humans don't need to do that. We kinda do the inverse of that, humans change the environment to suit them. Anyway, if you're immortal you're probably going to stop caring what people think after about a normal life time like a normal old person so being shunned wouldn't be a bad thing and there will always be someone around who wants to talk to an immortal. Personally I'd love to be immortal. I'd literally have all the time in the world to do whatever I wanted and after the world is gone in at the latest 4 billion years I'll probably have moved on to another planet, maybe even solar system, on some generation ship. Sounds like a good time to me