The archaeological record from the last millennium in southern California indicates that a period of significant cultural change was associated with a reported marine paleoenvironmental disruption ca. 1150-1250 A.D. A lengthy warm-water anomaly may have in part precipitated more complex sociopolitical and economic responses. We develop independent verification of the perturbation (originally deduced from sediment core data) using archaeological data. Respiratory pore number allometry in the black abalone shell is known to vary clinally in modern populations in response to temperature-induced variation in rate of growth. We use developmental trajectories of abalone from dated, stratified archaeological deposits to reconstruct prehistoric seawater temperatures.

Fluctuations in climatic regimes and biodiversity through time are linked in complex ways to human behavior and socioeconomic processes. We use macrobotanical evidence from Chumash village sites on California’s Channel Islands to investigate the relationship between late Holocene climatic perturbations and one region of the larger Chumash world. Carbonized plant remains provide evidence of the shifting availability of native plants during the Transitional period (A.D. 1150–1300), when droughts impacted island floral diversity and the Chumash had to cope with changes in vegetation regimes that likely curtailed food availability. We find that drought-resistant plant resources appear in higher relative frequencies in proveniences dating to the Transitional era, and at least one food resource was first imported from the mainland around that time. These findings support the proposition that the Chumash intensified cross-channel trade in part to respond to dietary needs during episodic resource stress. This is also the time when several economic specializations blossomed, including intensive shell bead making. These specializations persisted for six centuries and were central to the development of institutionalized leadership and political complexity in the region ca. A.D. 1200. Various strategies to preserve stability in the plant diet were important elements in the broader reorganization of labor in coastal southern California.

Social scientists recognize a complex and iterative relationship between the built environment and social identities. Here, we explore the extent to which household and settlement remains may be used as archaeological correlates of collective identities among the Stó:lō-Coast Salish peoples of the Fraser River Valley. Using data from six recently tested archaeological sites we begin with the household and explore expressions of identity at various social-spatial scales. The sites span the period from 4200 cal B.C. to the late A.D. 1800s and include settlements with semi-subterranean houses of different forms as well as aboveground plank houses. Across this timeframe we see both change and continuity in settlement location, layout, size, and house form. Our data suggest that although group identities have changed over the millennia, selected social units have persisted through many generations and can be linked to present-day identities of the Stó:lō-Coast Salish.

Recent publications debate the origins of the Chumash plank canoe (tomol) of southern California. The timing of its appearance is of considerable scholarly interest because of its significant role in the evolution of sociopolitical complexity among the coastal Chumash, who were among the world's most complex hunter-gatherers. This paper closely considers: (a) what constitutes reliable empirical evidence for canoe making and maintenance; (b) the most current estimate for the date of origin of this sophisticated watercraft (and the empirical foundations for such an estimate); (c) a scenario for the development of the tomol as a complex technological system (CTS) and why credit is appropriately assigned to the coastal Chumash for its development; and (d) the impacts of this technological system on Chumash sociopolitical evolution.

The later evolution of Chumash polities in various subareas, including the Channel Islands, has attracted considerable scholarly attention. Most investigations on this topic during the past decade have focused on economic and political evolution through the use of residential data (e.g., Arnold 1992a; Arnold, ed. 2001; Kennett 1998). Earlier, and now again with the publication of Gamble et al. (2001), cemetery data are marshaled to examine cultural change. While we applaud this recent effort, the utility of the results is constrained ultimately by factors including the representativeness of the excavated Malibu cemetery data, Mission period disruption of Ventureño Chumash culture, and insufficient attention to the consequences of mourning ceremonies. The authors add to an understanding of later Ventureño mortuary behavior, but their discussion conflates social ranking and political evolution. The results do not, contrary to their expectations, alter extant interpretations of Island Chumash production, specialization, and trade, nor the timing of changes in islanders' labor organization and political integration. The ultimate logical implication of their discussion would be that a single Chumash chiefdom evolved before (within?) the Middle period and operated in lockstep throughout the region—joining the Ventureño and Island Chumash at the political hip, so to speak. We see no evidence to support any part of this proposition for either of the subregions in question.

Prehistoric marine mammal hunting is of interest to archaeologists worldwide because these animals were exploited by a wide range of coastal societies. Sorting out the roles of particular groups of fauna in prehistoric economies requires detailed attention to the analysis of the entire faunal assemblage. Although marine mammals typically provided large quantities of fat and protein and were desirable prey, they were not always central to the diets of the groups that exploited them, particularly in temperate zones. To evaluate effectively the importance of marine mammal exploitation, scholars should calculate the relative contribution of these animals to the economy, identify changes in hunting techniques, determine the relationship between fauna and other aspects of society, assess changing environmental conditions, and consider alternate explanations for those relationships. A large body of research on the northern Channel Islands of California demonstrates that fishing was relatively more important than marine mammal exploitation in subsistence and in stimulating sociopolitical and technological developments. Recent attempts to credit marine mammal hunting as a driving force in the invention of the plank canoe and the evolution of a chiefdom in the Santa Barbara Channel area misunderstand environmental factors and site histories in this region. Rather than assuming that a pan-Pacific Coast set of traditions existed to exploit these taxa, we see evidence of local and regional differences rooted in variable cultural settings, physiographic and oceanographic conditions, and available technologies. Data from the Santa Barbara Channel are used to explore the relationships among marine mammal use, sociological change, and environmental change.

The 5′ untranslated region (UTR) of the long-lived Escherichia coli ompA transcript functions as an mRNA stabilizer that can prolong the cytoplasmic lifetimes of a variety of messages to which it is fused. Previous studies have identified two domains of this 5′ UTR that together are responsible for its stabilizing effect. One is a 5′-terminal stem-loop. The other is a single-stranded RNA segment (ss2) that contains a ribosome binding site highly complementary to 16S ribosomal RNA. Here we report a detailed investigation of the function of these two stabilizing elements. Our data indicate that mRNA protection by a 5′ stem-loop requires no sequence features or thermodynamic stability beyond the minimum necessary for stem-loop formation. Stabilization by ss2 appears to result not from a high frequency of translation initiation, but rather from a high degree of occupancy of this 5′ UTR segment by bound ribosomes. Although close spacing of translating ribosomes is not critical for message stabilization by the ompA 5′ UTR, mRNA longevity does require the periodic passage of ribosomes through the protein-coding region. Unlike bound ribosomes, which hinder mRNA cleavage by RNase E, the 5′ stem-loop appears to impede degradation of ompA mRNA via a distinct pathway that is RNase E-independent. These findings imply that the ompA 5′ UTR prolongs mRNA longevity by impeding multiple pathways for mRNA degradation.

Archaeological and ethnohistorical researchers in California are reaping the rewards from a wealth of new information about precontact and early historical cultural diversity, technologies, and marine and terrestrial ecosystems. Our recent investigations into the later prehistory of the island groups of southern California have centered on processes of sociopolitical evolution, including the emergence of status differentiation, evidence for intensification of craft production, and associated changes in human uses of animal resources as societies became more complex. We have linked some specific changes in diet, labor organization, and exchange to documented climatic disturbances, suggesting that opportunities created by such disruptions may have accounted in part for the timing of changes, but were not their cause in any mechanistic or simplistic sense. A recent American Antiquity report overlooks the primary results of this research and isolates the environmental data from a broad multidimensional model of cultural change in coastal California. We provide an update on the status of Channel Islands archaeology and identify the fundamental problems with approaches that extract and decontextualize environmental processes from cultural processes by assessing limited faunal data sets.

While new data about drought cycles are informative, patterns of ill health and violence and the origins of sociopolitical complexity in southern California are best understood through a broad consideration of multiple conditions and processes. These include various kinds of environmental and demographic conditions, changes in social and economic strategies, and changes in the organization of labor.

Ground-penetrating radar and other geophysical techniques are known to produce useful data when deposits are crisply structured, as in the case of sub-surface masonry walls or large ditches. New studies of Californian coastal sites find the methods are effective in tracing the less sharp distinctions that define clay and sand house floors within these large and dense hunter-gatherer middens.

The Chumash of the Santa Barbara Channel region were among the most economically and politically complex hunter–gatherer cultures of the New World. In recent decades, rich ethnohistorical documents pertaining to Chumash culture were analyzed, thus providing an excellent foundation for understanding the simple chiefdom that was in place as explorers and missionaries arrived in the sixteenth to eighteenth centuries. Current archaeological research on the Channel Islands focuses on the emergence of ranked society in Chumash prehistory, with special emphasis on political developments and environmental stresses that contributed to cultural evolution. A wide range of data acquired from the Channel Islands illuminates a new model of the rise of complexity. This model of chiefdom emergence is based on population-resource imbalances, political opportunism, and the manipulation of labor by rising elites. Diverse lines of evidence must be employed to evaluate the timing, causes, and consequences of increasing complexity.

Among the most complex and specialized hunter-gatherer-fisher societies in the New World, the peoples of the Santa Barbara Channel region of California were considered exceptional by early explorers because of their intense interest in valuables, beads and trade. During the last several centuries before European contact, sedentary populations on the offshore islands and mainland coast participated in an intensive regional exchange network that emerged from important earlier developments in transportation, craft specialization and labour organization. Especially significant in the sociopolitical evolution of this region were changes in the manipulation of domestic labour by a rising elite, expressed through increasing control over the production and distribution of status-rich valuables and critical resources. At historic contact, the Chumash who occupied the mainland coast and the northern Channel Islands (FIGURE 1) were probably organized into several interlinked small chiefdoms.

There are two basic concerns expressed in the comments by Haviland and Folan et al.: the possible exclusion from consideration of specific residential unit areas and the method for calculating labor investments. Although all the issues expressed may be legitimate, most have been explicitly addressed in our original article (Arnold and Ford 1980), and none alter our conclusions.

The widely applied concentric zonation model for Classic period Maya centers, which specifies that high-ranking persons lived closer to the central civic-ceremonial precinct than low-ranking persons, is tested for the site of Tikal. Our method is to identify residential units from the Carr and Hazard (1961) Tikal maps and to compute labor investment costs of construction of residential units from variables derived exclusively from the cartographic data. Our finding is that the Tikal data do not substantiate the concentric zonation model.