In a few areas there are rather puzzling features about some of the burials. For example, along the La Plata drainage there are too few burials to account for the rather large population that must have lived there. Diligent searching has failed to reveal how the La Plata people disposed of most of their dead. In other places skull burials are found—without any bodies—and sometimes bodies are found without any skulls. Perhaps some of these people practiced taking trophy heads of warriors killed in combat or ambush. Now and then burials are found with an arrow embedded in the body, or with scrape marks on the skull which indicate that a person had been scalped, or with the skull smashed in, as though by a stone ax. While open-armed warfare, as we know it today, was unfamiliar to the Pueblo Indians, life may not have always been calm and peaceful. Raiding or ambush parties, economic strife, the strains of increasing population, arguments over land and water rights, all may have contributed to making life uncertain during this period. And difficulties of a slightly different sort are shown in skeletons from Alkali Ridge in southwestern Utah, which show marked signs of malnutrition and diseases. This was evidently a period of growth, development, transition, and some struggle. As in other periods, it is difficult to place sharp lines of demarcation between the Pueblo Period and the earlier Basketmaker and between it and the later Great Pueblo Period. In all of the San Juan Basin, at any given moment, examples could be found of both old and new trends. Even in adjacent areas, there was no uniformity of cultural development. But by the end of this period, in one area or another, all the basic Pueblo traits were established. All that remained was for certain of these areas to become specialized along different lines, to become cultural “centers,” diffusing their ideas to neighboring groups, and in turn absorbing ideas from them. Throughout the San Juan Basin, the people were physically much alike; their language may well have been the same, or closely related, and there were probably free movements of people between towns and even between the more isolated groups and the larger centers of activity. It is doubtful if any group was completely isolated. Intermarriage must have been common. Whole family and clan groups may have left one village and joined another, sometimes only a short distance away, sometimes far away. It would be almost impossible to trace such minor shifts in population; large-scale mass migrations might leave their imprint on the archeological record, but such evidence does not seem to exist, and it is doubtful if any mass movements of people occurred at this time.