Culture and Ecology of Chaco Canyon and the San Juan Basin

332 Chaco Project Synthesispotential that studies in culture and ecology providefor explaining human behavior, and demonstrates howethnographic case studies can be used, not in analogy,but rather in homology, to shed light on thearchaeological record.Binford's Hunter-Gatherer StudiesBinford (2001) constructed his ecological frameof reference by evaluating worldwide terrestrialhabitats with regard to climate and available biomass.His goal was to anticipate variability in subsistencestrategies that result only from differences in theeffective environment, which affects relative dependenceon plants and animals, and in some instancesaquatic resources. Information on latitude, longitude,mean annual temperature, mean annual rainfall, meancoldest month, mean warmest month, mean rainfallduring the wettest and driest months, and the numberof months after the warmest month were used tocalculate effective temperature (E.T.). E.T. becamehis scaled measuring device for delineating whatsubsistence practices, either alone or in combination,would be followed if humans were simply anotherspecies in the larger ecological system that harvestedresources in proportion to availability.For 339 hunter-gatherer cases, the data recordedincluded 1) estimates of dependence on hunting,gathering, and fishing; 2) the size of the areaoccupied; 3) the total popUlation, its density per 100km 2 , and its group size during the most dispersedresidential period (group size 1), the aggregatedresidential period (group size 2), and annual orperiodic gatherings not necessarily focused on subsistence(group size 3); 4) the number of moves andtheir distances throughout the year, and whethermoves were into and out from a central location orfrom camp to camp; 5) the vegetation type in whichthe group was located; and 6) general soil type foundwithin the group's range. Seven types of system stateswere recognized: mounted hunters, agriculturalists,mutualists, egalitarian groups without leaders, egalitariangroups with leaders, ranked societies withwealth differences, and ranked societies with elitestatusgroups.When initial comparisons between environmentaldata and ethnographic cases were made, Binford(2001: 158) discovered that no hunter-gatherer caseswere located in true deserts and alpine tundra. Veryfew were found in semidesertic scrub areas, which arethe world's most prevalent plant formation and thesecond-driest environment in terms of annual rainfall.In these heavily water-stressed and nonproductivehabitats are found only pastoralists, agriculturalistswho use some form of irrigation or other unearnedwater resource, or industrial states (Binford 2001:137). As a result, he questioned prior reasoning thatplant domestication took place in areas where plantsoccurred in natural abundance. He also found aninverse relationship between the presence of ungulatesand hunter-gatherer populations. If domesticationmakes it possible for humans to utilize marginal areasthat were previously unoccupied and domesticationopens up new niches while increasing the productivityof older ones, he asked what factors led to changes inniche use and how they affected cultural systems.The domestication of either plants or animalsrepresents one form of intensification. Evaluation ofintensification due to subsistence stress indicated thathumans usually increase their dependence on terrestrialplants when the resource mix permits it(Binford 2001:212-213). Aquatic resources supplementa plant-based strategy or are adopted when plantswere inadequate to support a primary subsistencestrategy. Binford's research included discussions ofdifferent-size social units located within areasfavorable to plant, animal, or mixed subsistence bases.Large-scale Units. Analysis of data for westernEurope indicated that the lower the populationdensity, the later plant domesticates appeared. Exceptfor those populations dependent on terrestrial animals,once domestication occurred, there were dramaticincreases in ethnic group size among sedentary peoplesrelative to their mobile analogues. For these sedentarygroups, there also was a dramatic decrease in the sizeof the area used. There are a few exceptions, in whichthe number of persons and the size of the area increaseconcomitantly. These exceptional groups maintainmultiyear residential sites, and they are sociallycomplex. They tend to rely on aquatic resources, orthey may be mutualists or forest-product specialists, orpeople who recently adopted horticulture. Success inwarfare or alliance-building among sedentists also ledto increases in the area controlled as intensificationincreases (Binford 2001:223).