Collaborative Research: Demographic Transitions in Central California Prehistory

在美国国家科学基金会的支持下，耶尔默·埃尔肯斯和埃里克·巴特林克将研究加州中部的史前人口是如何应对环境变化和人口增长的。该研究将利用稳定同位素和对萨克拉门托-圣华金三角洲地区人类墓葬的古病理学分析，重建古代人类的健康、饮食、断奶习惯和活动模式。该项目是由两所学院的教师、研究生和本科生合作完成的，他们代表了生物考古学、考古学、考古测量学、稳定同位素生态学和地球化学等专业。加州中部是一个非常有趣的地区，因为该地区在全新世晚期（距今3500年，直到18世纪西班牙人接触）经历了指数级的人口增长。中心问题侧重于人口变化的速度，并利用多种证据来探讨人口增长是稳定的，还是随着环境变化而波动（例如，气候记录中报告的长期干旱）。在这方面，该研究将研究古代人类如何应对气候变化和战争等社会压力。人类骨骼为了解过去提供了一扇独特的窗口，因为它们代表了特定个体的生活史。这项研究将把这些个体的生活史整合到一个更广泛的图景中，即文化对人口增长、气候波动、营养压力、战争和疾病的适应。基于现有的人类学理论，研究者期望找到三种模式。首先，他们预计随着时间的推移，营养压力和疾病指标会增加，这反映出对质量较差的饮食的消费会增加，特别是在区域干旱等环境压力时期。人类骨骼和牙齿的稳定同位素分析将提供有关从不同生态系统（陆地、淡水和海洋）获得的膳食蛋白质、碳水化合物和脂肪来源的信息，这些信息将与骨骼和牙齿的压力和疾病指标进行比较。其次，研究人员预计，社会和环境压力增加的时期与父母对后代的投资减少有关，这可以通过儿童早期断奶和儿童饮食不良来衡量。这将使用第一磨牙牙本质系列切片的稳定同位素特征进行评估，牙本质形成于婴儿期和幼儿期。第三，研究人员使用锶和氧同位素对早期形成的牙齿和后期形成的骨骼进行了评估，预计随着人口增长，居民的流动性会下降。为了提供时间控制，将获得大量的放射性碳年代。这项研究的广泛影响将提供一个独特的数据集，记录史前时期狩猎-采集者的转变。这项研究将揭示气候变化如何影响健康、饮食、断奶和活动模式。此外，博士。Eerkens和Bartelink与美洲原住民社区的成员密切合作，以确保这项研究的结果得到广泛传播，包括向公众和研究团体传播。这项研究将有助于教育和培训考古学和体质人类学的学生，研究结果将在科学和公共论坛上发表，包括国家和地区会议、系列讲座和博物馆展览。

With National Science Foundation support, Drs. Jelmer Eerkens and Eric Bartelink will examine how prehistoric populations in Central California responded to environmental change and population growth. The research will reconstruct ancient human health, diet, weaning practices, and mobility patterns using stable isotope and paleopathological analyses of human burials from the Sacramento-San Joaquin Delta region. The project is a collaboration between faculty members, and graduate and undergraduate students from two institutions, representing specialties in bioarchaeology, archaeology, archaeometry, stable isotope ecology, and geochemistry. Central California is an area of significant interest because the region experienced exponential population growth during the late Holocene (~3500 years before present until Spanish contact in the 1700s). The central issue focuses on the rate of demographic change, and uses multiple lines of evidence to explore whether population growth was stable or if it fluctuated in concert with environmental changes (e.g., extended periods of drought reported in climatic records). In this respect, the research will examine how ancient human populations responded to climatic change and social stress such as warfare.Human skeletons provide a unique window into the past because they represent the life history of particular individuals. The study will merge those individual life histories into a broader picture of cultural adaptation to population growth, climatic fluctuations, nutritional stress, warfare, and disease. Based on existing anthropological theory, the researchers expect to find three patterns. First, they expect an increase in nutritional stress and disease indicators over time, reflecting greater consumption of poorer quality diets, especially during periods of environmental stress such as regional drought. Stable isotope analysis of human bone and teeth will provide information regarding the source of dietary protein, carbohydrates, and fats acquired from different ecosystems (terrestrial, freshwater, and marine), which will be compared with skeletal and dental indicators of stress and disease. Second, the researchers expect that periods of increased social and environmental stress will correlate with decreased parental investment in offspring, as measured by earlier weaning of children and poorer childhood diet. This will be evaluated using stable isotope signatures in serial sections of first molar tooth dentin, which forms in infancy and early childhood. Third, the researchers expect decreased residential mobility with increasing population growth, evaluated using strontium and oxygen isotope analysis of early forming teeth vs. later forming bone. To provide temporal control a large number of radiocarbon dates will be obtained. The broader impact of this research will provide a unique dataset documenting hunter-gatherer transitions in prehistory. The study will shed light on how changes in climate influenced health, diet, weaning, and mobility patterns. In addition, Drs. Eerkens and Bartelink have worked closely with members of the Native American community to ensure that the results of this research are widely disseminated, including to the public and research communities. The research will contribute toward educating and training archaeology and physical anthropology students, and the research will be presented in both scientific and public forums, including national and regional conferences, lecture series, and museum exhibits.