At some point the competition between groups became armed conflict. In the 1960's, a burial site was discovered along the Nile in ancient Nubia that provided what may be the earliest skeletal evidence for prehistoric warfare. The site dated to between 12,000 to 4500 BC and included the remains of 59 people, including women and children. Forty percent of the skeletons were found buried with small flake points, thought to be arrowheads. Points were found embedded in the bones of four skeletons.
Several individuals appear to have been executed, perhaps after already suffering other wounds.
Seven skeletons had arms fractured in a manner consistent with warding off blows. Increased economic incentives for war. Competition and incentive for armed conflict between groups grew once the agricultural revolution began. By 6000 BC, good agricultural or grazing land must have increased significantly in value where the new food gathering activities were taking hold. The food disparity widened between the newly rising agricultural towns and the marginal communities in the hills or on quickly exhausted lands.