Complex sentence: The development of the throwing-spear, together with ambush hunting techniques, made potential violence between groups very costly, dictating conflict avoidence, groups moving apart as far as possible to alleviate resource competition.
Split into simpler sentences: The development of the throwing-spear, together with ambush hunting techniques. This made potential violence between groups very costly, dictating conflict avoidence, which involved groups moving apart as far as possible to alleviate resource competition.