I've heard lots of conflicting evidence, and now I'm in a college class that is saying "It was impossible" and I'm quite confused by all the conflicting information. I also feel like my teacher uses very poor sources of information but i'm not sure and would like some info to check it against.
hi! this question could also be x-posted to /r/AskAnthropology, but there have been several threads here discussing this topic. Here are a couple that may be interesting