Not eating Pork is quite interesting to understand. In Islam and Judaism it's considered unclean. The primary reason for this is that before the days of refrigeration keeping pork fresh and edible was not an easy job. There could be no greater faux pas than to feed your guest bad meat !
However, there is an even more prehistoric reason for this tradition, one that dates back to early human history when many societies would turn cannibal in order to survive. Pork and Human flesh are similar, and difficult to distinguish. In an era of tribes, meeting another tribe and cooking them up something which could potentially be their own mother or son was quite taboo. Better to avoid all together. So these traditions found their way in to religious code.
For me, such things are an intriguing window into our past.