[quote=@PrinceAlexus] From a purely genetic point of view. A isolated group who remain so inbreeding becomes a issue. They weaken, they become less effective as time passes. A wider gene pool is stronger. They will outlast the isolationist who die and weaken as they inbreeding and genetic issues are passed down again and again. This only kicks inn over long period but in the end. The tribes, the large group always wins. [/quote] Well it doesn't take much imagination to figure out what happens when our lone survivalist is discovered by a tribe of dozens or more. If he's lucky, they will take him in or simply leave him alone, but it's also entirely possible that they will take all his stuff and leave, or just kill him outright. And there's not going to be anything he can do about it because he's outnumbered by such a huge factor. No need to wait for inbreeding to kick in, it's always the better choice to just go ahead and join a group if you can.