Climate change, human health, and resilience in the Holocene.

Climate change is an indisputable threat to human health, especially for societies already confronted with rising social inequality, political and economic uncertainty, and a cascade of concurrent environmental challenges. Archaeological data about past climate and environment provide an important source of evidence about the potential challenges humans face and the long-term outcomes of alternative short-term adaptive strategies. Evidence from well-dated archaeological human skeletons and mummified remains speaks directly to patterns of human health over time through changing circumstances. Here, we describe variation in human epidemiological patterns in the context of past rapid climate change (RCC) events and other periods of past environmental change. Case studies confirm that human communities responded to environmental changes in diverse ways depending on historical, sociocultural, and biological contingencies. Certain factors, such as social inequality and disproportionate access to resources in large, complex societies may influence the probability of major sociopolitical disruptions and reorganizations-commonly known as "collapse." This survey of Holocene human-environmental relations demonstrates how flexibility, variation, and maintenance of Indigenous knowledge can be mitigating factors in the face of environmental challenges. Although contemporary climate change is more rapid and of greater magnitude than the RCC events and other environmental changes we discuss here, these lessons from the past provide clarity about potential priorities for equitable, sustainable development and the constraints of modernity we must address.

Adapting in the Arctic: Habitual activity and landscape interaction in Late Holocene hunter-gatherers from Alaska.

OBJECTIVES: This study compares lower limb diaphyseal robusticity between Native Alaskan hunter-gatherers to reconstruct patterns of mobility and engagement with terrain. MATERIALS AND METHODS: Ancestral remains included in this study date between 600 and 1800 C.E. and were divided into three regions: Coastal Bay, Far North Coastal, and Inland/Riverine. Cross-sectional properties were determined at femoral and tibial midshafts and standardized by powers of body mass and bone length. RESULTS: Consistently elaevated areas and second moments of area were found in ancestral remains from the Far North Coastal, while the Coastal Bay remains had reduced diaphyseal robusticity. Individuals from the Inland/Riverine region were intermediate in robusticity for male femora, but similar to the Coastal Bay group for females. Sexual dimorphism was greatest in the Inland/Riverine ancestral remains and comparable between Coastal Bay and Far North Coastal regions. CONCLUSIONS: Ancestral remains from the Far North Coastal region have the greatest diaphyseal robusticity in response to intensive hunting and travel over rugged terrain. Reduced sexual dimorphism in the Far North Coastal region suggest female participation in hunting activities. Intermediate diaphyseal robusticity among Inland/Riverine males and increased sexual dimorphism reflects diverse patterns of mobility in relation to the hunting cycle between males and females. Reduced diaphyseal robusticity and sexual dimorphism among the Coastal Bay group is associated with sedentary villages established around net fishing in regions with low relief. Such findings argue against technocentric views of sedentism in hunter-gatherer lifeways and generally reflect diverse adaptive strategies and interaction with local terrain among Indigenous Late Holocene hunter-gatherers of Alaska.

Evaluating life history trade-offs through the presence of linear enamel hypoplasia at Pueblo Bonito and Hawikku: A biocultural study of early life stress and survival in the Ancestral Pueblo Southwest.

OBJECTIVES: Due to the indelible nature of enamel, bioarchaeologists use linear enamel hypoplasia (LEH) to detect early investments in surviving stress and have identified an association between LEH presence and constraints in growth and maintenance as well as an increased susceptibility to future stress events. This study evaluates heterogenous frailty and susceptibility to death in relation to episodes of early life stress, as reflected by LEH presence, in the Ancestral Pueblo Southwest. This study hypothesizes that LEH presence will be associated with decreased survivorship and an increased likelihood of mortality in both samples. MATERIALS AND METHODS: This study uses two samples, one from Pueblo Bonito (A.D. 800-1200; n = 28) and the second from Hawikku (A.D. 1300-1680; n = 103). Kaplan-Meier survival analysis with a log-rank test was used to evaluate the effect of LEH presence on survivorship for the two samples. RESULTS: Survival analysis reveals statistically significant differences in mortality risk between individuals with and without LEH for the Hawikku sample, but no significant differences for the Pueblo Bonito sample. CONCLUSION: The results demonstrate differences in the response to early life stress at the Hawikku and Pueblo Bonito sites, likely reflecting context. The Pueblo Bonito sample represents a high-status group, and survival following LEH may be the result of cultural buffering. Hawikku dates to a period associated with increased levels of disease and malnutrition as well as Spanish colonization. This environment may have exacerbated mortality risk for individuals in the region who survived early life stress and signifies the consequences of European colonialism in the New World.

Reproductive life histories influence cariogenesis: Exploring sex-specific variation in dental caries and survivorship in the human past.

OBJECTIVES: Differences in dental caries prevalence between males and females is considered a reflection of diet. However, recent syntheses argue that sex-specific variation in dental caries prevalence also reflects changes in the oral cavity attributable to variation in reproductive life histories. This study explores sex-specific variation in carious lesions using a life history perspective to understand if differences in reproductive ecology influence this process. MATERIALS AND METHODS: Survival probability between 860 males and females from the Terry Collection was compared using carious lesion manifestation (absent, crown presence, root/cemento-enamel junction [CEJ] presence) and sex as covariates and age as a time series variable. A four-way multivariate analysis of variance (MANOVA) comparing carious lesion type by sex, age, and periodontal disease presence was used to evaluate interaction between these variables. RESULTS: Individuals with carious lesions have greater survivorship than those without lesions. Males and females with crown lesions do not differ in survivorship from individuals without carious lesions. Females with root/CEJ lesions are characterized by the highest survivorship. A significant interaction was found for root/CEJ carious lesions by age, sex, and periodontal disease presence. Root/CEJ lesion formation in older males was not dependent upon periodontal disease presence, though dependence between these variables characterizes postmenopausal females. CONCLUSION: Sex-specific variation in crown lesions is not associated with reproductive life histories and likely reflects diet. By contrast, root/CEJ lesions form through pathways attributable to reproductive life histories, particularly age-induced periodontal disease in females. These results suggest the formation of carious lesions is complex, and in some cases, rooted in reproductive life histories.

Bioarchaeological evidence for adaptive plasticity and constraint: Exploring life-history trade-offs in the human past.

The Developmental Origins of Health and Disease paradigm evaluates the consequences of early life stress on health at later stages of life. Interacting with this paradigm represents a profound opportunity to leverage the lifespan and contextual approaches to human skeletal remains adopted by bioarchaeological research. Teeth and bone provide evidence for stressors experienced early in life. These events represent evidence for adaptive plasticity as Individuals survive the events through reallocation of energy to essential physiological functions, which inhibits enamel and skeletal growth. Age-at-death, adult body size, chronic infection, or childhood mortality may be used as covariates to better understand the physiological constraints operating on individual bodies following survival of early life stress. Contextual evidence from cemeteries provides clues to the ecological and cultural contingencies that exacerbate or mitigate the expression of these trade-offs. Future studies should incorporate newly derived methods that provide reproducible and precise ways to evaluate early life stress, while incorporating populations that are often neglected.

Crypt fenestration enamel defects and early life stress: Contextual explorations of growth and mortality in Colonial Peru.

OBJECTIVES: This study provides a comprehensive analysis of crypt fenestration enamel defects (CFEDs) from the Eten and Mórrope communities, Colonial period (A.D. 1,530-1,750), Lambayeque Valley, Peru. The goal is to help clarify the role of these lesions as reflections of early life environments as well as relationships growth and survival at future ages. MATERIALS AND METHODS: CFED absence/presence was recorded in the mandibular canines of 105 individuals and 202 teeth. Defect prevalence was compared between the Eten and Mórrope sites using a proportions test. Femoral growth residuals were compared between CFED present and absent samples. Mortality risk was evaluated using Kaplan-Meier survival analysis. RESULTS: CFED frequencies at Eten and Mórrope were similar to previous studies. Greater frequencies of CFEDs were found at Eten compared to Mórrope. There was no association between skeletal growth and CFEDs. No differences in mortality were found between CFED present and absent individuals within each site. General survivorship at Eten was significantly greater than Mórrope. However, individuals without CFEDs at Eten had greater survivorship than those with and without CFEDs at Mórrope. Individuals with CFEDs at Eten had greater survivorship than those with CFEDs at Mórrope. These differences begin around 1.7 years. CONCLUSIONS: CFEDs may be associated with stress experience, but associations with growth and survivorship at later ages is context dependent. CFED prevalence is an ambiguous indicator of stress when used in the absence of mortality data, and even under those circumstances, appears limited by differences in local demography.

Diachronic changes in craniofacial morphology among the middle-late Holocene populations from Hehuang region, Northwest China.

OBJECTIVES: This study analyzes craniofacial shape variation in the Hehuang region of Northwest China within a population genetic framework, and takes a diachronic approach to explore the relationship betwee cultural discontinuity and biological continuity/discontinuity in the Hehuang region during the middle to late Holocene. MATERIALS AND METHODS: The sample comprises 76 adult skulls from five archaeological sites, ranging from 4,500 to 1,530 BP. 3D geometric morphometrics, multivariate statistics, quantitative evolutionary genetic and biodistance analyses were performed to study the diachronic variation in craniofacial morphology. Analyses were performed on two cranial modules: the face and the cranial vault, across three major diachronic groups representing the late Neolithic (LNA), the Bronze Age (BA), and the Han-Jin dynasty (HD). RESULTS: Average regional FST for both cranial modules was low, indicating relatively greater variation within diachronic groups than among them. While the LNA and BA groups did not show any significant differences in facial and vault shape, significant craniofacial shape changes were detected between the BA and HD groups. DISCUSSION: The consistent craniofacial morphology during the LNA and the BA, and the shift in morphology between the BA and the HD indicates that cultural discontinuity does not always coincide with biological discontinuity. The Hehuang population evolved in situ with few changes, despite cultural and dietary changes, until the HD when migrations from the Central Plains are associated with extra-local gene flow to the area.

Plasticity and constraint in response to early-life stressors among late/final Jomon period foragers from Japan: evidence for life history trade-offs from incremental microstructures of enamel.

This study evaluates two hypotheses that address how Late/Final Jomon period people responded to early-life stress using linear enamel hypoplasia (LEH) and incremental microstructures of enamel. The first hypothesis predicts that Jomon people who experienced early-life stressors had greater physiological competence in responding to future stress events (predictive adaptive response). The second hypothesis predicts that Jomon people traded-off in future growth and maintenance when early investment in growth and survival was required (plasticity/constraint). High resolution tooth impressions were collected from intact, anterior teeth and studied under an engineer's measuring microscope. LEH were identified based on accentuated perikymata and depressions in the enamel surface profile. Age of formation for each LEH was estimated by summing counts of perikymata and constants associated with crown initiation and cuspal enamel formation times. The relationship between age-at-first-defect formation, number of LEH, periodicity between LEH, and mortality was evaluated using multiple regression and hazards analysis. A significant, positive relationship was found between age-at-death relative to age-at-first-defect formation and a significant, negative relationship was found between number of LEH relative to age-at-first-defect formation. Individuals with earlier forming defects were at a significantly greater risk of forming defects at later stages of development and dying at younger ages. These results suggest that Late/Final Jomon period foragers responded to early-life stressors in a manner consistent with the plasticity/constraint hypothesis of human life history. Late/Final Jomon period individuals were able to survive early-life stressors, but this investment weakened responses to future stress events and exacerbated mortality schedules.

Bioarcheology has a "health" problem: conceptualizing "stress" and "health" in bioarcheological research.

This article provides a critical historical overview of the stress concept in bioarcheological research and critically evaluates the term "health" in reference to skeletal samples. Stress has a considerable history in 20th century physiological research, and the term has reached a critical capacity of meaning. Stress was operationalized around a series of generalized physiological responses that were associated with a deviation from homeostasis. The term was incorporated into anthropological research during the mid-20th century, and further defined in bioarcheological context around a series of skeletal indicators of physiological disruption and disease. Emphases on stress became a predominate area of research in bioarcheology, and eventually, many studies utilized the terms "health" and "stress" interchangeably as part of a broader, problem-oriented approach to evaluating prehistoric population dynamics. Use of the term "health" in relation to skeletal samples is associated with the intellectual history of bioarcheological research, specifically influences from cultural ecology and processualist archeology and remains problematic for two reasons. First, health represents a comprehensive state of well-being that includes physiological status and individual perception, factors that cannot be readily observed in skeletal samples. Second, the categorization of populations into relative levels of health represents a typological approach, however unintentional. This article advocates for the integration of methodological and theoretical advances from human biology and primatology, while simultaneously incorporating the theoretical constructs associated with social epidemiology into bioarcheological research. Such an approach will significantly increase the applicability of bioarcheological findings to anthropological and evolutionary research, and help realize the goal of a truly relevant bioarcheological paradigm.

Skeletal growth in early and late Neolithic foragers from the Cis-Baikal region of Eastern Siberia.

Skeletal growth is explored between Early Neolithic (EN) (8000 to 6800 BP) and Late Neolithic (LN) (6000 to 5200 BP) foragers from the Cis-Baikal region of Eastern Siberia. Previous studies suggest that increased systemic stress and smaller adult body size characterize the EN compared to LN. On this basis, greater evidence for stunting and wasting is expected in the EN compared to LN. Skeletal growth parameters assessed here include femoral and tibial lengths, estimated stature and body mass, femoral midshaft cortical thickness, total bone thickness, and medullary width. Forward selection was used to fit polynomial lines to each skeletal growth parameter relative to dental age in the pooled samples, and standardized residuals were compared between groups using t tests. Standardized residuals of body mass and femoral length were significantly lower in the EN compared to LN sample, particularly from late infancy through early adolescence. However, no significant differences in the standardized residuals for cortical thickness, medullary width, total bone thickness, tibial length, or stature were found between the groups. Age ranges for stunting in femoral length and wasting in body mass are consistent with environmental perturbations experienced at the cessation of breast feeding and general resource insecurity in the EN compared to LN sample. Differences in relative femoral but not tibial length may be associated with age-specific variation in growth-acceleration for the distal and proximal limb segments. Similarity in cortical bone growth between the two samples may reflect the combined influences of systemic and mechanical factors on this parameter.

A comparative study of stress episode prevalence and duration among Jomon period foragers from Hokkaido.

This study reconstructs linear enamel hypoplasia (LEH) prevalence and stress episode duration among Jomon period foragers from Hokkaido, Japan (HKJ). Results are compared to Jomon period samples from coastal Honshu, Japan (HSJ) and Tigara Inupiat from Point Hope, Alaska (PHT) to provide a more comprehensive perspective on the manifestation of stress among circum-Pacific foragers. LEH were identified macro- and microscopically by enamel surface depressions and increased perikymata spacing within defects. Individuals with more than one anterior tooth affected by LEH were labeled as LEH positive. Stress episode durations were estimated by counting the number of perikymata within the occlusal wall of each LEH and multiplying that number by constants reflecting modal periodicities for modern human teeth. LEH prevalence and stress episode duration did not differ significantly between the two Jomon samples. Significantly greater frequencies of LEH were found in HKJ as compared to PHT foragers. However, HKJ foragers had significantly shorter stress episode durations as compared to PHT. This suggests that a greater proportion of HKJ individuals experienced stress episodes than did PHT individuals, but these stress events ended sooner. Similarity in stress experiences between the two Jomon samples and differences between the HKJ and PHT are found. These findings are important for two reasons. First, stress experiences of foraging populations differ markedly and cannot be generalized by subsistence strategy alone. Second, due to significant differences in episode duration, stress experiences cannot be understood using prevalence comparisons alone.

Adapting in the Arctic II: Upper limb diaphyseal robusticity and habitual activity in Late Holocene hunter-gatherers from Alaska.

OBJECTIVES: This study compares humeral diaphyseal robusticity and asymmetry between Late Holocene hunter-gatherers from Alaska with the goal of reconstructing habitual activity in relation to culture and environment. MATERIALS AND METHODS: Ancestral remains from four geographic regions of Alaska were divided into five site groups defined by subsistence strategies and technology: Aleutian Islands, Coastal Bay, Far North Coastal, Inland/Riverine, and Tikeraq. Mid-distal humeral diaphyseal robusticity was quantified using cross-sectional geometric properties standardized by estimated body mass and bone length. RESULTS: Humeral strength and bilateral asymmetry were greatest in Aleutian Island males, moderate in Far North Coastal and Tikeraq males, and reduced in Inland/Riverine males. Left-biased directional asymmetry and reduced humeral strength were found in Coastal Bay males. Aleutian Island males had relatively mediolaterally strengthened humeri compared with other groups. Aleutian Island females had elevated humeral strength, while humeral asymmetry among females was moderate and did not vary between groups. Humeri were relatively round among Aleutian Island and Tikeraq females and anteroposteriorly (A-P) strengthened among Coastal Bay, Far North Coastal, and Inland/Riverine females. CONCLUSIONS: These results suggest elevated humeral strength and asymmetry in males that engaged in rowing and unimanual projectile hunting, while reduced humeral strength and asymmetry may reflect bow-and-arrow or ensnarement technologies. Left-biased humeral asymmetry may be associated with net-fishing. Humeral strength and asymmetry are consistent with select instances of unimanual projectile hunting in females, while differences in humeral A-P/mediolateral strength may reflect variation in butchery and processing of prey versus rowing and throwing behaviors.

Developmental variation in ecogeographic body proportions.

While ecogeographic variation in adult human body proportions has been extensively explored, relatively less attention has been paid to the effect of Bergmann's and Allen's rules on human body shape during growth. The relationship between climate and immature body form is particularly important, as immature mortality is high, mechanisms of thermoregulation differ between young and mature humans, and immature body proportions fluctuate due to basic parameters of growth. This study explores changes in immature ecogeographic body proportions via analyses of anthropometric data from children included in Eveleth and Tanner's (1976) Worldwide Variation in Human Growth, as well as limb proportion measurements in eight different skeletal samples. Moderate to strong correlations exist between climatic data and immature stature, weight, BMI, and bi-iliac breadth; these relationships are as strong, if not stronger, in immature individuals as they are in adults. Correlations between climate and trunk height relative to stature are weak or nonexistent. Altitude also has significant effects on immature body form, with children from higher altitudes displaying smaller statures and lower body weights. Brachial and crural indices remain constant over the course of growth and display consistent, moderate correlations with latitude across ontogeny that are just as high as those detected in adults. The results of this study suggest that while some features of immature body form, such as bi-iliac breadth and intralimb indices, are strongly dictated by ecogeographic principles, other characteristics of immature body proportions are influenced by intrinsic and extrinsic factors such as nutrition and basic constraints of growth.

Twenty-first century bioarchaeology: Taking stock and moving forward.

This article presents outcomes from a Workshop entitled "Bioarchaeology: Taking Stock and Moving Forward," which was held at Arizona State University (ASU) on March 6-8, 2020. Funded by the National Science Foundation (NSF), the School of Human Evolution and Social Change (ASU), and the Center for Bioarchaeological Research (CBR, ASU), the Workshop's overall goal was to explore reasons why research proposals submitted by bioarchaeologists, both graduate students and established scholars, fared disproportionately poorly within recent NSF Anthropology Program competitions and to offer advice for increasing success. Therefore, this Workshop comprised 43 international scholars and four advanced graduate students with a history of successful grant acquisition, primarily from the United States. Ultimately, we focused on two related aims: (1) best practices for improving research designs and training and (2) evaluating topics of contemporary significance that reverberate through history and beyond as promising trajectories for bioarchaeological research. Among the former were contextual grounding, research question/hypothesis generation, statistical procedures appropriate for small samples and mixed qualitative/quantitative data, the salience of Bayesian methods, and training program content. Topical foci included ethics, social inequality, identity (including intersectionality), climate change, migration, violence, epidemic disease, adaptability/plasticity, the osteological paradox, and the developmental origins of health and disease. Given the profound changes required globally to address decolonization in the 21st century, this concern also entered many formal and informal discussions.

Ontogeny of limb proportions in late through final Jomon period foragers.

This study reports on developmental patterning in the intralimb indices of Late/Final Jomon period (4000-2300 BP) people. Jomon foragers represent the descendants of migrants from Northeast Asia, who arrived in the Japanese Islands around 20,000 BP. Among adults, Jomon brachial indices are elevated and similar to warm adapted, low latitude people, while crural indices are intermediate and similar to people from moderate latitudes. Two hypotheses regarding the development of intralimb indices among Jomon period foragers are tested: (1) intralimb indices of Jomon people maintain predicted ecogeographic relationships over ontogeny; (2) greater evolvability will be observed in the brachial index, while greater developmental constraint will be observed in the crural index. Changes in intralimb proportions in a Jomon skeletal growth series are compared to those in two contrasting samples: Inuit from Point Hope (cold adapted) and Nubians from Kulubnarti (warm adapted). A quadratic equation best describes the ontogeny of brachial and crural indices, with high indices in infancy followed by a decline in childhood and an increase in adolescence. Despite these shifts, ecogeographically predicted differences and similarities in the indices are maintained between samples throughout ontogeny. In addition, radial relative to humeral length is significantly less correlated than tibial relative to femoral length. These results suggest genetic conservation of intralimb indices over the course of development. However, radial and humeral lengths are less correlated than tibial and femoral lengths among Jomon subadults and adults, potentially suggesting greater evolvability of the brachial index and more developmental constraint on the crural index.

Variability in dental caries prevalence between male and female foragers from the Late/Final Jomon period: Implications for dietary behavior and reproductive ecology.

OBJECTIVES: This study documents sex differences in dental caries prevalence among Late to Final Jomon period (4000 through 2300 BP) foragers from Japan and interprets the results within behavioral, dietary, and reproductive context. METHODS: The presence/absence of carious lesions was recorded from ∼1600 Late/Final Jomon period teeth. Frequencies and mean numbers of carious teeth were compared between males and females according to age, tooth group, and region using Fisher's exact and t tests. RESULTS: Significantly greater frequencies of carious molar teeth were observed in females compared to males in each age group. Few differences were observed between older and younger females as well as between females from high and low density regions. Significantly greater prevalence of cariogenic molars were, however, observed between females in Age Group 3 from a high compared to low density region. Significantly greater average numbers of carious molar teeth were found in females compared to males, with no significant differences in mean number of carious teeth between age groups. CONCLUSIONS: Differences in carious teeth between the sexes likely reflect behavioral and dietary variation for males and females. Limited differences in caries prevalence and mean number of carious teeth between female age groups and regions of varying population density suggests that reproductive factors played a minor role in dental caries variation between males and females.

Patterns of systemic stress during the agricultural transition in prehistoric Japan.

This study documents and interprets systemic stress during the agricultural transition in prehistoric Japan using linear enamel hypoplasia (LEH) defects and cribra orbitalia (CO) lesions. Middle to Final Jomon cultures (5000-2300 BP) from Honshu Island represent the foraging samples, while Yayoi cultures (2500-1700 BP) represent the early agricultural samples. Jomon foragers from eastern Japan had broad-based, intensive economies. Jomon foragers from western Japan had a greater focus on seasonally available, nutritionally poor resources, while Yayoi people were descendents of migrants from the East Asian continent and introduced wet rice economies to Japan. This study tests the hypotheses that wet rice economies will be associated with a lower prevalence of teeth/individuals affected by LEH defects in western Japan, while few differences in the prevalence of teeth/individuals with LEH defects will be observed between eastern Jomon people and Yayoi farmers. It is further predicted that similar CO prevalence will be observed between Jomon and Yayoi people given environmental similarities. Significantly greater frequencies of teeth affected by LEH defects are observed among western Jomon compared to Yayoi people. The prevalence of teeth with LEH defects is slightly elevated among eastern Jomon foragers compared to Yayoi agriculturalists. Significant differences in CO prevalence are not observed. Systemic stress prevalence in western Japan likely declined following wet-rice agriculture because this crop provided a predictable, renewable resource base. Systemic stress prevalence was similar between eastern Jomon and Yayoi people because both groups practiced intensive subsistence strategies. Similar CO prevalence reflects infectious diseases associated with living conditions.

Variation in limb proportions between Jomon foragers and Yayoi agriculturalists from prehistoric Japan.

Variation in limb proportions between prehistoric Jomon and Yayoi people of Japan are explored by this study. Jomon people were the descendents of Pleistocene nomads who migrated to the Japanese Islands around 30,000 yBP. Phenotypic and genotypic evidence indicates that Yayoi people were recent migrants to Japan from continental Northeast Asia who likely interbred with Jomon foragers. Limb proportions of Jomon and Yayoi people were compared using RMA regression and "Quick-Test" calculations to investigate relative variability between these two groups. Cluster and principal components analyses were performed on size-standardized limb lengths and used to compare Jomon and Yayoi people with other groups from various climatic zones. Elongated distal relative to proximal limb lengths were observed among Jomon compared to Yayoi people. Jomon limb proportions were similar to human groups from temperate/tropical climates at lower latitudes, while Yayoi limb proportions more closely resemble groups from colder climates at higher latitudes. Limb proportional similarities with groups from warmer environments among Jomon foragers likely reflect morphological changes following Pleistocene colonization of the Japanese Islands. Cold-derived limb proportions among the Yayoi people likely indicate retention of these traits following comparatively recent migrations to the Japanese Islands. Changes in limb proportions experienced by Jomon foragers and retention of cold-derived limb proportions among Yayoi people conform to previous findings that report changes in these proportions following long-standing evolution in a specific environment.

What can variation in stature reveal about environmental differences between prehistoric Jomon foragers? Understanding the impact of systemic stress on developmental stability.

This study reconstructs patterns of stress and phenotypic variation in prehistoric Japan. Greater evidence for stress is indicated by elevated enamel hypoplasia frequency among Jomon foragers from western compared to eastern Japan. Geographic variation in stress between Jomon people is related to plant-based diets and resource scarcity in western Japan. The hypothesis that Jomon people from western Japan had shorter stature than those from the east is, therefore, tested. Relationships between individual stature, geographic location, and enamel hypoplasia presence/absence are also explored. In addition, increased population density and reliance on plant foods are observed during the Late/Final Jomon period in western Japan. A second hypothesis proposing shorter stature for Late/Final Jomon people compared to those from the Middle Jomon period is tested. Statistically significant differences in stature between males and females from eastern and western Japan were not observed. Individual relationships between enamel hypoplasia and stature were rejected. Stature decreased significantly over time in western Japan. It is possible that stature between the eastern and western Jomon did not differ because the western Jomon experienced catch up growth after childhood stress episodes. It is also likely that variation in stress between the two groups was not severe enough to warrant stature reduction. Decreases in stature through time in western Japan are related to increased exposure to chronic infection and dietary stress. Overall, these results indicate that enamel hypoplasia frequencies provide an adequate index of general stress but may fail to predict the impact of stress on the human phenotype.

Dental caries prevalence as evidence for agriculture and subsistence variation during the Yayoi period in prehistoric Japan: biocultural interpretations of an economy in transition.

The Yayoi period represents the earliest point of agricultural dependence in Japan, dating from approximately 2500 BP to AD 300. Yayoi period people consumed wet-rice as a primary subsistence base. This article uses dental caries prevalence to interpret the biocultural implications of agriculture among these people by testing the following hypotheses: 1) Yayoi period agriculturalists had greater frequencies of carious teeth than Jomon period foragers, 2) regional variation in carious tooth frequencies will be observed among Yayoi period agriculturalists, while 3) variation in carious tooth frequencies will be observed between male and female agriculturalists. Statistically significant differences in carious teeth were observed between the agriculturalists from Southern Honshu and all other samples. These differences suggest greater reliance on cariogenic plants among farmers from Southern Honshu and are consistent with an agricultural economy. The people of the Yayoi period from Tanegashima Island and Northern Kyushu did not have significantly different carious tooth frequencies compared to Jomon period foragers. This suggests that rice alone was not a more cariogenic dietary substance than those consumed by Jomon period foragers but a cariogenic food nonetheless. Dietary heterogeneity between the prehistoric people of the Yayoi period from Southern Honshu and those from Northern Kyushu and Tanegashima Island is also inferred from these differences. Significantly greater frequencies of carious teeth among older aged Yayoi period females compared with males suggest dietary differences between the sexes.