The roots are their texts AND their teachers (priests or imams or sheikhs) who use the teachings to get power and wealth. It's about the same for all kinds of fundamentalists. You can see the same roots on 13th Avenue in Brooklyn, where the Chasids have each sect's territory marked out, as if at war with other sects. THE root is the human species genetic force to band together in packs. Chimps do it. As far as FUNDAMENTALISM appears to be the matter at hand, the headmen in the Islamic world can manipulate their rabbles and keep them under control. But then Attah, Yussef, and bin Laden are hardly rabble -- they are headmen! So was Muhammad. Notice please that the great imams don't seem to have condemned terrorism or religious errors. Yadda yadda!