American Great Basin Research Articles

A multi-modeling approach to evaluating climate and land use change impacts in a Great Lakes River Basin

River ecosystems are driven by linked physical, chemical, and biological subsystems, which operate over different temporal and spatial domains. This complexity increases uncertainty in ecological forecasts, and impedes preparation for the ecological consequences of climate change. We describe a recently developed “multi-modeling” system for ecological forecasting in a 7600 km2 watershed in the North American Great Lakes Basin. Using a series of linked land cover, climate, hydrologic, hydraulic, thermal, loading, and biological response models, we examined how changes in both land cover and climate may interact to shape the habitat suitability of river segments for common sport fishes and alter patterns of biological integrity. In scenario-based modeling, both climate and land use change altered multiple ecosystem properties. Because water temperature has a controlling influence on species distributions, sport fishes were overall more sensitive to climate change than to land cover change. However, community-based biological integrity metrics were more sensitive to land use change than climate change; as were nutrient export rates. We discuss the implications of this result for regional preparations for climate change adaptation, and the extent to which the result may be constrained by our modeling methodology.

Genetic analysis across different spatial scales reveals multiple dispersal mechanisms for the invasive hydrozoan Cordylophora in the Great Lakes

Discerning patterns of post-establishment spread by invasive species is critically important for the design of effective management strategies and the development of appropriate theoretical models predicting spatial expansion of introduced populations. The globally invasive colonial hydrozoan Cordylophora produces propagules both sexually and vegetatively and is associated with multiple potential dispersal mechanisms, making it a promising system to investigate complex patterns of population structure generated throughout the course of rapid range expansion. Here, we explore genetic patterns associated with the spread of this taxon within the North American Great Lakes basin. We collected intensively from eight harbours in the Chicago area in order to conduct detailed investigation of local population expansion. In addition, we collected from Lakes Michigan, Erie, and Ontario, as well as Lake Cayuga in the Finger Lakes of upstate New York in order to assess genetic structure on a regional scale. Based on data from eight highly polymorphic microsatellite loci we examined the spatial extent of clonal genotypes, assessed levels of neutral genetic diversity, and explored patterns of migration and dispersal at multiple spatial scales through assessment of population level genetic differentiation (pairwise F(ST) and factorial correspondence analysis), Bayesian inference of population structure, and assignment tests on individual genotypes. Results of these analyses indicate that Cordylophora populations in this region spread predominantly through sexually produced propagules, and that while limited natural larval dispersal can drive expansion locally, regional expansion likely relies on anthropogenic dispersal vectors.

Feeding ecology of the Great Basin Rattlesnake (Crotalus lutosus, Viperidae)

Documenting variation in organismal traits is essential to understanding the ecology of natural populations. We relied on stomach contents of preserved specimens and literature records to assess ontogenetic, intersexual, temporal, and geographic variations in the feeding ecology of the North American Great Basin Rattlesnake ( Crotalus lutosus Klauber, 1930). Snakes preyed mainly on rodents, occasionally on lizards, and less frequently on birds; squamate eggs and frogs were rarely eaten. There was a positive relationship between predator and prey size. The best predictors of this relationship were prey diameter as a function of snake body length and head size, underscoring the importance of prey diameter for gape-limited predators such as snakes. Crotalus lutosus displayed ontogenetic, sexual, and seasonal variations in diet. Smaller rattlesnakes fed predominantly on lizards, whereas larger individuals mostly fed on mammals. Females fed on lizards more often than males. The proportion of mammals in the diet was highest during the summer, a temporal variation that may be related to behavioral shifts in the diel activity and prey selectivity of C. lutosus, and (or) to differential abundance of rodents between seasons. Great Basin Rattlesnakes also displayed geographic variation in feeding habits, with snakes from the Great Basin Desert eating a higher proportion of lizards than serpents from the more northern Columbia Plateau.

A Century of Mormon Theory and Practice in Church-State Relations: Constancy Amidst Change

The Church of Jesus Christ of Latter-day Saints (the Mormons) has the dubious distinction of having passed through the most prolonged and intense confrontation between church and state in American history. The earliest history of the Mormons was marked by hostile and violent confrontations with their neighbors as they were driven from state to state. After forming their own commonwealth in the remoteness of the American Great Basin, they faced further confrontation, this time with a federal government bent of eradicating the Mormon practice of plural marriage and the unique economic and political institutions and practices that the Mormons had created. In 1890, the church publicly abandoned plural marriage and the legal pressure abated. During the course of the twentieth-century the legal challenges faced by the church largely centered on its aggressive international expansion, which brought the Mormons into contact with legal regimes all over the world. This paper argues that despite the dramatic changes in Mormon church-state practices there is nevertheless a consistent and coherent approach focusing on the theological imperative to maintain the independence and continuity of the church's institutional structure.

Antiquity of early Holocene small-seed consumption and processing at Danger Cave

When did people start to eat small seeds, and what drove them to it? New investigations and dating at the Danger Cave in the American Great Basin show that seeds (pickleweed seeds) did not become part of the staple diet until after 8700 b.p. It was at this time that animal and plant resources had begun to seriously diminish in a shrinking wetland.

Tracking Toxaphene in the North American Great Lakes Basin. 1. Impact of Toxaphene Residues in United States Soils

A coupled atmospheric transport model was employed to study six scenarios to assess the contribution of reemission and long-range transport of toxaphene from different sources in the United States to its environmental fate in the Great Lakes ecosystem in the year 2000. Modeled air concentrations at the first model level (1.5 m) range from less than 5 pg m(-3) over the upper Great lakes (Lakes Superior and Huron) to several tens of picograms per cubic meter over the lower Great Lakes (Lakes Erie and Ontario) in the summer but drop off to the range from 0.05 to 2 pg m(-3) in the wintertime. The modeled toxaphene depositions to the lakes suggest a decreasing trend from the mid-1990s to 2000. Modeling results showed that, on an annual basis, for the Great Lakes basin as a whole, the southeast U.S. sources made the largest contribution to the toxaphene air concentrations and dry and wet depositions at 72%, 78%, and 88% respectively. The model results also showed that a significant proportion of these contributions occur during relatively short episodic events due primarily to the interseasonal changes in atmospheric circulation patterns.

Statistical methods for bioarchaeology: applications of age-adjustment and logistic regression to comparisons of skeletal populations with differing age-structures

Previous studies of patterns of osteoarthritis involvement in prehistoric skeletal populations have been used to suggest differences in lifestyle or subsistence patterns. In spite of the intriguing nature of such studies, inadequate controls for the potential confounding effects of age have made results less secure than they appear. While researchers remain unable to control for the inherent limitations imposed by preservation bias, meaningful advancement could be made in the analysis of these data. Here we propose two methods from epidemiology that would allow more robust comparisons between populations with differing age-structures: age-adjustment and logistic regression. We apply these two methods to previously published data from prehistoric populations of the American Great Basin. In doing so, we are able to discern sex differences in risk for osteoarthritis at the shoulder (beta = −1.82, SE = 0.74, OR = 0.16, 95% CI = 0.04–0.69, p = 0.013), elbow (beta = −2.07, SE = 0.82, OR = 0.13, 95% CI = 0.03–0.63, p = 0.011), and in the foot (beta = −3.11, SE = 1.57, OR = 0.04, 95% CI = 0.00–0.97, p = 0.048), that were not noted in previous analyses of these data. These findings suggest that greater clarity of results and more precise comparisons of risk may be achieved by using these methods. We conclude that further application of these methods to bioarchaeological studies would potentially improve what can be said about prehistoric health patterns and lifeways.

Scenes from the High Desert: The Life and Theory of Julian Steward

Virginia Kerns, Urbana: University of Illinois Press, 2003, xiv + 414 pages.Reviewer: Marc Pinkoski University of VictoriaA very strong argument could be made that Julian Steward was one of the most influential anthropologists of the 20th century. Virginia Kern's recent biography, Scenes from the High Desert: The Life and Theory of Julian Steward, goes a tremendous distance to demonstrate this assertion. In a thoroughly researched, accessibly written, and lyrically enjoyable text, Kerns has well documented the life, both academic and personal, of Julian Steward.Her study follows the life of Steward, as a boy from the east coast of the United States to the desert of California; from Berkeley to Utah to Washington, D.C.; and then on to New York, to Columbia University, and finally to the midwest (with stops along the way). Centring on one of Steward's key concepts, the patrilineal band, Kerns prepares a descriptive analysis of Steward's life and by association the seminal people in the formation of American materialist anthropology. Her analysis serves to explore the workings of this particularly anthropological concept, as it applies to the life history of its originator. Her success is that she creates an analysis that not only documents the life of someone worthy of a biography, but it also documents much of the focus, structure, and psychological workings in American anthropology, and particularly, the incredible prejudice experienced by women, within the academy mid-last century. Through the focus on Steward's life and career, Kerns has produced an effective biography that manages to situate the subject within his historic-academic context. The analysis is more than a simple biography; it is, in fact, an ethnohistory of American anthropology through an examination Steward's life.Steward's materialist arguments are often remembered or imagined as the introduction of Marxist analyses to anthropology. This effect, as Kerns' recognizes, places Steward in a key role in the history of American anthropology. She describes his approach as having ...a propensity for the concrete and that [h]e used an impressive array of ethnographic and archaeological evidence to support a range of creative, generalizing conclusions about how, in his own words, 'similar subsistence activities had produced similar social structures' (p. 3). This approach led him to develop the sub-field of cultural ecology, and to train several key materialist anthropologists in the process. For these reasons, it is fascinating to understand the details of Steward's life, and to come to a fuller appreciation of the lives that Steward was influenced by and in turn influenced.Beginning with Steward's formative years, Kerns argues that he was heavily influenced by problems inherent in the daily life of arid environments and the labour that it takes to organize irrigation work to solve them. Following this focus was Steward's initial academic and then professional material on the American Great Basin. Kerns demonstrates that the focus on the organization of subsistence labour and its relationship to the physical environment remained a central component in Steward's oeuvre on development and change. Detailing fully Steward's early ethnographic and archaeological work and demonstrating the full mix of personal responsibilities and professional desires for the ambitious young scholar, Kerns relates the stories of his development from both his first and second wives. These perspectives from both women well compliment the public and professional history of Steward's academic career. A particular example of this dynamic was his move from the University of Utah. This was due to the break-up of his first marriage and overlapped with his second marriage. …

Response of North American Great Basin Lakes to Dansgaard–Oeschger oscillations

We correlate oscillations in the hydrologic and/or cryologic balances of four Great Basin surface-water systems with Dansgaard–Oeschger ( D–O) events 2–12. This correlation is relatively strong at the location of the magnetic signature used to link the lake records, but becomes less well constrained with distance/time from the signature. Comparison of proxy glacial and hydrologic records from Owens and Pyramid lakes indicates that Sierran glacial advances occurred during times of relative dryness. If our hypothesized correlation between the lake-based records and the GISP2 δ 18O record is correct, it suggests that North Atlantic D–O stades were associated with relatively cold and dry conditions and that interstades were associated with relatively warm and wet conditions throughout the Great Basin between 50,500 and 27,000 GISP2 yr B.P. The Great Basin lacustrine climate records reinforce the hypothesis that D–O events affected the climate throughout much of the Northern Hemisphere during marine isotope stages 2 and 3. However, the absolute phasing between lake-size and ice-core δ 18O records remains difficult to determine.

Skeletons in our closet: revealing our past through bioarchaeology

PREFACE ix ACKNOWLEDGMENTS xv INTRODUCTION Tales from the Dead: What Bones Tell Us about Our Past, and Why We Should Know 3 CHAPTER 1 The Lives and Lifestyles of Ancient Hunter-Gatherers: Poor, nasty, brutish and short in the American Great Basin? 13 CHAPTER 2 Skeletons from Stillwater. Good Times and Bad Times 35 CHAPTER 3 From Foraging to Farming. A Regional Perspective 65 CHAPTER 4 Going Global: Bioarchaeology of the Foraging-to-Farming Transition 96 CHAPTER 5 Europeans Arrive: Circumstances and Settings for Native Population Collapse in the Americas 121 CHAPTER 6 Bioarchaeology of Population Decline and Extinction in Spanish Florida 145 CHAPTER 7 Sot-Weed to Sangamo: Life and Death in Frontier North America 179 Chapter 8 On to Sangamo Country: Colonizing the Midwest 203 Chapter 9 Life's Transitions: The Bioarchaelogical past 228 Index 237

High disease incidence and apparent disease tolerance in a North American Great Basin plant community

Patterns and consequences of plant disease at the community level have rarely been studied. We surveyed fungal infection in a Great Basin community of perennial shrubs over 4 years. Repeat surveys in fixed plots and along transects showed that disease incidence in the dominant perennial species was often very high, with up to 100% of all individuals infected. Despite the widespread prevalence of infection, and its severity on individual plants (which sometimes had over 1/3 of their leaves covered in pustules), its effects on survival and flowering were undetectably small. Thus, this perennial community appears to be stable, despite widespread disease. There are two potential explanations for this pattern; either the pathogens have evolved to be avirulent, or the hosts have become tolerant to being infected. Avirulence is not likely, because multiple infections are common in this system, and multiple infections have been shown in other species to favor strains that are faster reproducing and thus more virulent. Instead, it is more likely that tolerance has evolved in these host species, because infection in each year is practically inevitable and because the host plants are long-lived, giving little opportunity for new resistance genotypes to evolve.

Narcissus's Mirror: Manufacture and Modernism in the American Great Basin—The Case of Pottery

The commodification of pottery cannot be reduced to strict econo-technological terms. Commodification is a cultural process, enmeshed in local, regional, and international systems of meaning. As Victorian Modernism eroded, anti-modern movements commodified “traditional” culture. These philosophies, themselves commodities, had repercussions on the pottery industry throughout the world. In both America and Australia, these processes produced art and studio potteries. In the American Great Basin, these changes were experienced very differently by potters from different cultures. The commodification and industrialization of modern pottery factories predicated the reification of a pre-industrial artisanal past.

Limnological conditions in Mono Lake: contrasting monomixis and meromixis in the 1990s

Mono Lake is a large, saline lake, located in the North American Great Basin and is subject to large variations in freshwater inflow as climatic conditions and diversion schemes have changed; consequently, major variations in chemical stratification occur. A transition from monomixis to meromixis occurred from 1994 to 1995. Lake-wide surveys of temperature, conductivity, dissolved oxygen, ammonium and chlorophyll profiles, Secchi depth and light attenuation, and Artemia monica abundances conducted throughout 1993, 1994, 1995, 1996 and 1997 document the contrasts between monomixis and meromixis. During the monomictic conditions in 1993 and 1994, the lake thermally stratified in March and mixed to the bottom by December, the hypolimnion became anoxic in late March and the water column was oxygenated to the bottom by December. During meromictic conditions in 1995, 1996 and 1997, the absence of holomixis during winter resulted in persistent anoxic conditions beneath the chemocline, an accumulation of ammonium in the monimolimnion and depletion in the mixolimnion, and low mixolimnetic chlorophyll concentrations in the spring and autumn. A comparison of the density differences between 2 and 28 m due to thermal versus chemical stratification indicated thermal stratification predominated in 1993 and 1994, while in 1995, 1996 and 1997 chemical stratification dominated the density differences. Ammonium, the limiting nutrient in Mono Lake, was lower in the upper mixed layer throughout 1996 and 1997 compared to the monomictic years, 1993 and 1994. During 1996 and 1997, the annual maxima in Secchi depths were among the deepest observed during the past 19 years, and reflected the lower phytoplankton abundance caused by decreased availability of nitrogen as a result of strong chemical stratification and the absence of a period of holomixis. In both 1996 and 1997, maturation of the spring generation of Artemia was slowed, peak abundance of the first generation of adult Artemia was a month later and percent ovigery, fecundity, and body size were reduced as compared to 1993 and 1994.

Lake Bonneville fluctuations and global climate change

Lake Bonneville, the largest late Pleistocene closed-basin lake in the North American Great Basin, fluctuated widely in response to changes in climate. The geochemistry and mineralogy of endogenic calcium carbonate deposited in deep water, and stratigraphic studies of shore-zone deposits, provide evidence of millennial-scale lake-level fluctuations that had amplitudes of about 50 m between 30 and 10 ka. Falling-lake events occurred at 21, 18.5–19, 17.5, 16–15.5, 14–13, and 10 ka (radiocarbon years) synchronously with the terminations of Heinrich events H1 and H2 and other smaller scale iceberg-rafting events (a, b, c, and Younger Dryas) in the North Atlantic Ocean. The Lake Bonneville results thus support other climate records that suggest that late Pleistocene millennial-scale climate change was global in extent. The size and shape of the Northern Hemisphere ice sheets, which determined the mean positions of storm tracks, may have been the primary control on late Pleistocene water budgets of Great Basin lakes.

Julian Steward and the Politics of Representation: A Critique of Anthropologist Julian Steward's Ethnographic Portrayals of the American Indians of the Great Basin

The main battle in imperialism is over land, of course; but when it came to who owned the land, who had the right to settle and work it, who kept it going, who won it back, and who now plans itsfuture-these issues were reflected, contested, and even for a time decided in narrative.’ The expansive region of the American Great Basin and its indigenous peoples hardly appear in most renditions of American history. Representing only a tiny fraction of the continent’s populace, the histories of the lands and peoples of this vast region remain largely excluded from the broader narratives of North American history. Unlike historians, anthropologists for the past century have maintained considerable interest in the Indians of the Great Basin. This paper examines the re resentations of Great Basin Indians by Julian Steward-t K e preeminent anthropologist of the region. Developing theories

The influence of shade and clouds on soil water potential: The buffered behavior of hydraulic lift

In the sagebrush/bunchgrass steppe of the North American Great Basin soil water potential has been shown to exhibit diel fluctuations with water potential increasing during the night as a result of water loss from roots in relatively dry soil layers. We hypothesized that environmental conditions promoting low transpiration rates (shading, cloudiness) would cause a net increase in soil water potential as a result of reduced soil water depletion during the day and continuing water efflux from roots during the night. We examined the response of soil water potential to artificial shading in sagebrush/bunchgrass plantings and used a simple model to predict how soil water potential should respond to reduced transpiration. Field measurements of soil water potential indicated that shading reduced daytime soil water depletion, but that the magnitude of the soil water potential increase during the night was related to the magnitude of the soil water potential decline during the preceding day. As a result, shading had little net effect on soil water potential. This behavior was consistent with model results and appears to result from the fact that soil water depletion during the day is largely responsible for creating the water potential gradients that drive nocturnal recharge of the shallow soil layers. The overall effect of such behavior is to buffer the seasonal course of soil water depletion in the rooting zone against day-to-day fluctuations in evapotranspiration. Despite the buffered behavior of soil water potential change, reduced evapotranspiration during light summer rains, and resulting soil water redistribution in the rooting zone, may enhance plant water status to a greater extent that would be expected on the basis of the rainfall received.

Temporal changes in root growth and 15N uptake and water relations of two tussock grass species recovering from water stress

Physiological responses of Agropyron desertorum and Pseudoroegneria spicata, two common cold desert perennial tussock grass species of the North American Great Basin, were evaluated during and after a period of imposed drought in a pot study. The timing and the pattern of response of leaf water potential (Ψ1), stomatal conductance (gs), and root growth were strikingly similar in both species during and after drought. The severity of stress influenced the magnitude of Ψ1 and gs, but had little effect on the timing of these responses. Although drought inhibited total root length in prestressed plants, within 4 days after relief of drought both species showed similar increases in root growth which exceeded those of the control. Despite similarities in their root growth responses to increased soil water availability, the two grasses differed in their capacity to restore N uptake following drought. By 14 days after rewatering, N uptake in the prestressed Agropyron had recovered to levels of control plants, although both root biomass and root lenght were much less than those of the controls. This is attributed to elevated root uptake kinetics. Restoration of N uptake by prestressed Pseudoregneria was much less effective during the same period.

Effectiveness of phosphate acquisition by juvenile cold-desert perennials from different patterns of fertile-soil microsites.

Phosphate uptake was measured for Artemisia tridentata, Agropyron desertorum and Pseudoroegneria spicata, three common perennial North American Great Basin species. Four patterns of nutrient-rich microsites were used in the experiments (different distances, densities and nutrient concentrations) All species were more efficient at taking up P from microsites nearest the plants than from more distant microsites. Artemisia and Agropyron acquired P more rapidly from the distant microsites when there was a larger number of microsites and, therefore, a greater probability of encounter. Uptake from the nearest microsites did not increase after 26 days, while uptake from distant microsites increased and was equal to uptake from the nearest microsites by the end of the experiment. Phosphate uptake was four to five times higher for Artemisia than for Agropyron on a shoot mass basis and seven to eight times greater than for Pseudoroegneria, which reflects species relative growth rates. Differences in shoot dry mass were significant among species, but little evidence was found for interspecific competition. Root density, root dry mass and P uptake in the upper part of the soil mixture was higher for Artemisia than the other species. Phosphate acquisition seems to be influenced by the distance of microsites and their density and the ability of plants to encounter and proliferate absorbing organs in the microsites.

Gheo‐shih: an ancient pre‐Columbian plaza

Abstract This paper describes the configuration and cultural context of the oldest known designed space in central America, Gheo‐Shih, dating from 5,000 – 4,000 BC. This site may have been a ceremonial space, being employed in a similar fashion to ceremonial spaces of Native American cultures from the North American Great Basin. It contains physical features that set precedents and are similar to the geomantic features of later nearby Mesoamerican cultures.

The foreign impact on Lowland Mayan language and script By John S. Justeson, William M. Norman, Lyle Campbell, and Terrence Kaufman (review)

BOOK NOTICES 727 longing to five different sub-branches: Aramaic, Ammonite, Canaanite, Mideanite and Gileadite; and Ammonite, in turn, as Canaanite or Arabic. G attempts to identify all dialectal differences of phonology (Ch. 2, pp. 23-78), morphology (Ch. 3, 79-166), and syntax (Ch. 4, 167-204). He admits that lexico-semantic isoglosses are 'potentially valid', and believes in using the Swadesh list for the comparisons; however, few of the Swadesh items actually occur in NWS inscriptions. Feasibility thus may depend on choosing alternative vocabulary items. For example , C. A. Ferguson (Lg. 35.616-30, 1959) used the verb ?a/ 'see' in colloquial Arabic dialects (among other items) to postulate descent from a hypothetical Arabic koine—as opposed to the classical language, which used the common Semitic verb ra'ä. Such differences may contribute a great deal to dialect geography, as well as to the hows and whys of language change. Ch. 5 (215-40), 'The dialectical continuum of Syria-Palestine', presents G's results of the entire investigation; e.g., the lsg. pronoun groups Phoenician, Sam'alian, and Moabite together, as opposed to Old Aramaic and Hebrew. G is unsure (217) as to whether phonological or morphological features offer a better basis for classification , but affirms (216) that syntax is most unreliable. He further concludes (229) that Phoenician and Aramaic represent the extremes ofNWS 'dialects'; Ammonite is the closest relative to Phoenician, and Deir 'Alia to Aramaic. The bibliography is extensive (241-60); but there was no need to repeat so much of the bibliographic information in the notes following the chapters. [Alan S. Kaye, California State University , Fullerton.] The foreign impact on Lowland Mayan language and script. By John S. Justeson, William M. Norman, Lyle Campbell, and Terrence Kaufman. (Middle American Research Institute, Publication 53.) New Orleans: Tulane University, 1985. Pp. vii, 97. This monograph is an important demonstration of the rewards of studying the interface between linguistics and archaeology in the reconstruction of culture history. The use ofpast and present linguistic boundaries to define ethnic boundaries is traditional in archaeology. Questions of cultural diffusion, migration, abandonment of areas etc., have always been addressed in terms of language groups—e.g. the on-going question over the archaeological evidence for the 'Numic expansion' in the American Great Basin. Areas of shared culture are seen as areas ofshared language. For Eastern Meso-America, however, there has been an unfortunate lack of communication between linguists and the archaeologists . Culture history in this area has been reconstructed on the basis of material remains and ethnohistorical sources, with little attention to historical linguistics. This volume is thus a welcome bridge between the disciplines. The goal of the work is clearly stated in the opening paragraph of the introduction: it is 'to identify evidence for the impact of foreign groups on the spoken and written languages of the Lowland Maya and to determine what this evidence indicates about social interaction between the ancient Lowland Maya and foreign peoples'. Part I presents the authors' current understanding of language history—specifically , of lexical diffusion—in the Lowland Mayan language area. The area is defined, linguistic chronology is discussed, and sources of lexical borrowing are reviewed, including Zapotecan , Mixe-Zoquean, Nahua, and Totonacan . Part II deals with foreign influences on the Mayan hieroglyphic writing. After clarifying which features ofwriting systems are indicative ofhistorical relationships and which are not, the authors argue persuasively for an Olmec origin for Meso-American writing; this then branched into a Oaxacan group to the west, and a Southeastern group which eventually led to the Classic Mayan script. Part III discusses several important conclusions drawn from the preceding parts. The linguistic chronology of Lowland Mayan and neighboring Mayan groups is refined. Absolute dates for linguistic divergence, based on evidence presented in the Parts I—II, are compared with glottochronological estimates for the same splits. The results are surprisingly consistent , giving strong support to glottochronology as a method of estimating language diversification . Social implications of diffusion between both spoken and written vocabularies are discussed ; and extensive interaction between Greater Izapan and Lowland Mayan people in the Preclassic Period is suggested. The linguistic identification ofTeotihuacán is proposed as To- 728 LANGUAGE, VOLUME 62...