This sounds like a great premise for a novel, and the question could be explored at a quite deep level. Consider that most ecosystems are now codependent on hu

This sounds like a great premise for a novel, and the question could be explored at a quite deep level. Consider that most ecosystems are now codependent on human civilization, and many locales do not have the necessary flora or water availability to support stone age civilization. There are certainly some ecosystems such as fishing communities north of Vancouver that would do well and be shielded from any nuclear exchange, but the wild deer population in Massachusetts would likely not be sufficient for any significant number of modern stone age men to survive.