Okay, so there has been a lot of talk around here that Nick and Nate seem to have some sort of uncanny resemblance (and Kenny but that's beside the point here). I've looked at them both and they actually do look very similar in many aspects. So here's my theories:
1.) Pete mentions Nicks dad was hardly ever there for him and was "a piece if shit" when he was. This coordinates with Nate's crazy and unpredictable personality. There's one problem though. Age. Nick seems like he is around 20-22 and Nate maybe 30-35 or 35-40. Now maybe Nate just looks young for his age, or maybe my second theory is more plausible
2.) Nate is Nicks older brother. Everything would match up with theory one except that Nate could be younger than we think he is and maybe him and Nick got separated at the beginning of apocalypse.
3.) This theory matches with both my first and second theory. There had been speculation that Carver may be Nate. It's been stated that Carver or people from his group were in the cabin group before. This would explain Nate and Nick being related and being in the same group. Nate possibly went crazy, ran off (this is where we meet him as Russell) and then became some kind of bandit leader (Carver).
Do you have any Nate/Nick theories? Discuss amongst yourselves :)
(Here's pictures of Nick and Nate for comparison.)