Doctoral Dissertation Research: Dental Analysis of Classic Period Population Variability in the Maya Region

博士论文研究：玛雅地区古典时期人口变异的牙科分析

• 批准号: 0234006
• 负责人: Lori Wright
• 金额: $ 0.19万
• 依托单位: Texas A&M Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-15 至 2003-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0234006&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Dental; Analysis

This research will examine biological variability among the Classic period Maya using dental metric and nonmetric data from ancient human skeletal remains. Analyses of biological distance and variability within physical anthropology can be classified as model-free and model-bound. In model-free approaches, low levels of biological variability are treated as evidence for high levels of related ancestry and gene flow. In contrast, model-bound approaches take into account the affects of genetic drift and thus provide a more satisfying model of ancient population dynamics. In this study, both model-free and model-bound approaches will be utilized. One of the major benefits of applying model-bound analyses to the study of the Classic Maya is the availability of large skeletal samples sizes from archaeological sites with well-known population estimates and well-controlled chronologies; factors that have been difficult to control in previous model-bound analyses. This study will address problems both specific to Maya archaeology and will produce a large data set on Pre-Columbian Central American dental morphology, furthering our understanding of ancient biological variation in the Americas. In this study of ancient Maya biological variation, Scherer will test the hypothesis that biological distance between Classic period Maya site populations is correlated with geographic distances between sites. This hypothesis rests on the assumptions that migration between Maya urban centers was relatively minor and that increases in population size were largely due to natural population growth. Current archaeological evidence, however, suggests that these assumptions are not correct. Recent studies of Maya demography have demonstrated that numerous sites exhibit fluctuations in population size during the Classic period. Migration, including movement across major archaeological regions, may be one explanation for these episodes of growth and decline. Further, the Maya historical record describes numerous migration events during the Classic period, including inter-site marriages, the placement of foreign lords at subjugated sites, and the founding of new sites by splintering dynastic lineages. What is lacking, however, is an understanding of ancient Maya population history from a biological perspective. This research will fill that void by providing the first comprehensive study of biological variation in the Maya lowlands.If this research determines that populations were not stable, as posited in the first hypothesis, it will be necessary to evaluate what segments of ancient Maya society were mobile. Thus, Scherer will test a second hypothesis that when gene flow occurred during the Classic period, it was primarily at the elite level of society. The data for each site will be partitioned into elite and non-elite segments based on burial context and mortuary variability. If elite migration was more substantial than non-elite migration, we should expect greater biological differentiation between sites for commoners than for the elite. As an additional way to examine population stability during the Classic period, the samples will be divided by time period to examine the relative degree of genetic continuity through time for each site. In order to test these hypotheses, Scherer will collect dental metric and nonmetric data from 15 sites representing seven of the archaeological zones in the Maya region. Statistical analyses will employ both model-free and model-bound approaches. Model-free statistics will include Mahalanobis D2 (metrics) and the mean measure of divergence (nonmetrics). Model-bound analyses will follow recent statistical modifications of the R matrix model of migration for metric and nonmetric data. This award will have the broader impact of contributing to the professional development of the student and providing him with an international experience.

本研究将使用古代人类骨骼遗骸的牙齿计量和非计量数据来检查古典时期玛雅人的生物变异。体质人类学中对生物距离和变异的分析可分为无模型和有模型两类。在无模型方法中，低水平的生物变异被视为高水平的相关祖先和基因流动的证据。相比之下，模型绑定的方法考虑了遗传漂变的影响，从而提供了一个更令人满意的古代种群动态模型。在本研究中，将使用无模型方法和有模型方法。将模型绑定分析应用于经典玛雅研究的主要好处之一是，可以从具有众所周知的人口估计和良好控制的年表的考古遗址中获得大量骨骼样本；在以前的模型约束分析中难以控制的因素。这项研究将解决玛雅考古学特有的问题，并将产生关于前哥伦布时期中美洲牙齿形态的大量数据集，进一步加深我们对美洲古代生物变异的理解。在这项古玛雅生物变异的研究中，Scherer将检验古典时期玛雅遗址种群之间的生物距离与遗址之间的地理距离相关的假设。这一假设基于这样的假设：玛雅城市中心之间的迁移相对较少，人口规模的增长主要是由于人口的自然增长。然而，目前的考古证据表明，这些假设是不正确的。最近对玛雅人口统计的研究表明，许多遗址在古典时期表现出人口规模的波动。迁徙，包括跨越主要考古区域的迁徙，可能是这些增长和衰退的一种解释。此外，玛雅的历史记录还描述了古典时期的许多迁移事件，包括遗址间的通婚、在被征服的遗址安置外国领主，以及通过分裂的王朝血统建立新的遗址。然而，缺乏的是从生物学角度对古玛雅人口历史的理解。这项研究将填补这一空白，为玛雅低地的生物变异提供第一个全面的研究。如果这项研究确定人口不稳定，就像第一个假设所假设的那样，那么就有必要评估古代玛雅社会的哪些部分是流动的。因此，Scherer将检验第二个假设，即当基因流动发生在古典时期时，它主要发生在社会的精英阶层。每个地点的数据将根据埋葬背景和太平间的可变性划分为精英和非精英部分。如果精英移民比非精英移民更重要，我们应该期待平民比精英更大的生物差异。作为检验经典时期种群稳定性的另一种方法，样本将按时间段划分，以检验每个地点随时间的遗传连续性的相对程度。为了验证这些假设，Scherer将从代表玛雅地区七个考古区域的15个地点收集牙齿计量和非计量数据。统计分析将采用无模型和有模型两种方法。无模型统计将包括马氏D2（度量）和平均散度度量（非度量）。模型绑定分析将遵循最近对度量和非度量数据迁移的R矩阵模型的统计修改。该奖项将对学生的专业发展产生更广泛的影响，并为学生提供国际经验。