There's an evolutionary advantage to having people who are isolated from the rest of the community. And not just in terms of sickness transmission. Things such as war, famine, and natural disasters can wipe out whole population groups.
I'm a little skeptical. Isolated individuals cannot successfully reproduce a population. Furthermore, those who intentionally isolate themselves seem less likely to achieve reproductive success in the event that, say, they stumbled across a suitable mate, or a post-disaster survivor encampment.
Perhaps I read the article wrong, but I was under the impression that he came back to society after 27 years. This would mean if there had been a disaster while he was gone, his genes would make up a much higher percentage of the population than if he had stayed.
He was still living near and reliant on other people for food and energy supplies. If shit really hit the fan and those disappeared, it's not clear he would survive either.
When I said isolated I meant it in exactly that fashion. Isolated and withdrawn, but close enough to still fall back into society if the need - due to internal or external reasons - arose. Someone removing themselves from even the remote chance of human interaction is unlikely to have any evolutionary advantage. And unless I'm reading the article wrong, he did eventually rejoin the masses after 27 years.
I guess was talking about people who feel the need to withdraw in general. I think we've all met a person or two like this, who prefered to be alone. Some just take it further than others.
