Culture and Ecology of Chaco Canyon and the San Juan Basin

296 Chaco Project Synthesisnecessarily be a change in the underlying conceptsregarding social organization that were in place atthese population centers. If cooperating segmentsmaintained decisionmaking power, and the ability tofission alleviated the need for the highest level ofcooperating segments, then a return to earlier patternsis likely.Assuming that mobility was always an option ifone cared to move far enough, Schillaci's (2003)craniometric analysis suggests that the Chaco populationconsisted of at least four distinct groups, someof whom had ancestors from the north and whoeventually migrated to either the Hopi-Zuni or RioGrande areas. His results suggest movements of longdistances over time from southwestern Utah to ChacoCanyon (Pueblo Bonito western group) to later ancestralTiwa sites in the Taos area. The Durango areaof southwestern Colorado may have been ancestral tothose buried in the northern rooms at Pueblo Bonito,and their descendants may have moved toward theZuni area. The more homogeneous position of Aztecin Schillaci's study suggests a mixed group that drewfrom many lineages. The "Pax Chaco" (LeBlanc1999, 2000; Stuart 2000) that provided safe interactionand assistance across the region may representthe height of an integrating mechanism that developedearly among the northern groups and resulted in thedual social organization pattern that continues today.The droughts from A.D. 1130 to 1180 correlatewith decreased use of the canyon. Whether a remnantpopulation remained in the canyon or whether theMesa Verde occupation represents people moving backinto the area is yet to be determined, but McKenna's(1991) suggestion that Mesa Verde pottery is theculmination of a black-on-white tradition deservesadditional consideration. Droughts in the late A.D.1200s have been considered the cause for abandonmentof the area. There is a lack of Pueblo use ofthe central San Juan Basin and the Four Corners areaduring and after a second major drought at approximatelyA.D. 1275; Dean et al. (1994) indicate that aperiod of degradation with low water tables and hightemporal variability in moisture ensued until aboutA.D. 1500. These conditions would not make thecentral San Juan Basin an attractive area for agriculturalists.If violence and warfare among competinggroups (LeBlanc 1999, 2000), or even cannibalism(Bustard 2000; Turner and Turner 1999), occurred asthe result of insufficient food during droughts orperiods of poor crop returns, there may have been asocial taboo against moving back into the ancestralarea. Fowler et al. (1987), Lekson and Cameron(1995), Roney (1995, 1996), and Stuart (2000)document how different groups dispersed intoperipheral areas, most in the highlands. Hill et al.(2004), and Wilcox (Wilcox et al. 2003, 2004, 2005)model the dispersion of sites with 50 or more roomsfrom A.D. 1200 to 1600. As people moved apart,they lost the long-term settlement and leadershipwithin a central area. Without the large settlementswith numerous priestly leaders, some other integratingsocial mechanisms may have been emphasized.Katsinas add a new integrative feature to thesocial structure. The origin of katsinas is stilldebated. E. C. Adams (1991) proposed they began inthe Little Colorado area. Schaafsma and Schaafsma(1974) thought they originated in Mogollon territory.Crotty (1995) sided with Adams, and Lekson andCameron (1995) suggested they may have been presentin Chaco. Katsinas are well defined by A.D. 1250,when people are moving out of the F our Corners area.The question should be: What role do they fill?Historically, they assist in teaching the generalpopulation how to behave while they added a newintegrative feature to the social structure.If dual social organization began duringBasketmaker II in the northern San Juan and had along history of integrating different genetic andpossibly ethnolinguistic groups, then an emphasis ondifferent aspects of long-established traditions atdifferent times is not unexpected, given the hundredsof years that have elapsed since the dispersal of thesegroups from the Four Corners area through ChacoCanyon and into the distinct territories we recognizetoday for the Hopi, Zuni, Acoma-Laguna, and RioGrande settlements. With more distance separatingthe settlements and possibly less frequent interaction,the variations seen among historic Pueblo groupswould not be unexpected. Although some means ofmaintaining social intercourse would be necessary,their different trajectories, especially after eastern andwestern tribes interacted with Europeans, wouldprovide different historical patterns.When we admit the presence of at least two, butprobably more, distinct populations living in Chaco