Doctoral Dissertation Improvement: Mesoamerican Population Structure and Interregional Interaction

在国家科学基金会的支持下，布莱恩·奥布里将对整个中美洲的26个骨骼种群进行生物考古学研究，这些骨骼种群的历史可以追溯到公元600 - 1000年。 这项研究并不特别关注这些变化的原因，而是通过分析牙齿变异是否可以从生物学上检测到可能发生的任何人口统计学变化。 从历史上看，研究人员假设在古典时期和后古典时期，来自墨西哥中部的人口在不同时期向南迁移到玛雅地区。 虽然关于墨西哥中部对整个中美洲的影响程度存在重大争议，但大多数人认为确实发生了移民，并且接触的考古证据表明人口的移动。 尽管玛雅-墨西哥关系对中美洲史前史的重要性被认为是重要的，但这将是第一个足够规模的生物考古学研究，以帮助解决这个问题。在一项研究中纳入来自中美洲各地的材料对于回答研究中提出的研究问题至关重要。 这项研究的范围将允许检测人口结构随时间的变化，并隔离从外部流入玛雅地区的基因来源。特别重要的是，要将每个分区域内优先与其各自区域以外的地点相互作用的特定地点隔离开来。 研究的具体任务是：1）评估三个子区域中每个子区域内位点的生物学距离，以检测离群值; 2）计算每个子区域的遗传杂合性水平，并将单个位点与这些预期值进行比较; 3）比较每个子区域内表现出大于预期遗传杂合性水平的特定位点的生物学距离。 确定不同次区域的具体地点之间的相互作用范围，这将有助于阐明墨西哥中部对玛雅地区的影响的性质。该项目的独特之处在于，它是中美洲使用公制和非公制牙科数据进行的最大规模的生物亲和力研究，也是第一个记录所有个人牙骨质-釉质连接（CEJ）和牙冠测量的项目。该研究的学术价值源于其对促进我们目前对中美洲泛区域相互作用的理解的贡献，以及增加了关于树冠和CEJ测量之间一致性的现有文献。该项目的更广泛影响是其对中美洲历史重要时期研究的贡献。此外，研究人员将能够访问大约3,500人的原始数据，而不是汇总数据，以与他们自己的数据进行比较，或对这些数据进行额外的统计应用。

With National Science Foundation support, Bryan Aubry will conduct bioarchaeological research on 26 skeletal populations from throughout Mesoamerica dating between 600-1000 A.D. Dramatic sociopolitical and demographic shifts during this period have been inferred from archaeological and ethnohistoric data, but there is currently no consensus regarding the nature of interaction between the sub-regions of Mesoamerica. The study is not specifically concerned with the cause of these shifts, but rather with whether or not any demographic shifts that may have occurred can be detected biologically through the analysis of dental variation. Historically, researchers have hypothesized that populations from Central Mexico migrated south into the Maya region at various times during the Classic and Postclassic periods. Although there is significant debate over the degree of influence that central Mexico exercised throughout Mesoamerica, most assume that migration did occur and that archaeological evidence of contact indicates the movement of populations. Despite the perceived importance of the Maya-Mexican relationship to Mesoamerican prehistory, this will be the first bioarchaeological study of sufficient scale to help resolve this issue. The inclusion of materials from all over Mesoamerica in a single study is essential to answer the research questions posed in the study. The scope of the study will allow for the detection of changes in population structure through time and for the isolation of sources of gene flow into the Maya area from outside. Of particular importance is the isolation of particular sites within each sub-region that preferentially interacted with sites outside of their respective area. The specific tasks of the research are 1) to assess the biological distance of sites within each of the three sub-regions to detect outliers; 2) to calculate levels of genetic heterozygosity for each sub-region and compare individual sites to these expected values, 3) to compare the biological distance of specific sites within each sub-region that exhibit greater than expected levels of genetic heterozygosity. The identification of spheres of interaction between specific sites from different sub-regions that deviate from what is expected will help illuminate the nature of central Mexican influence in the Maya area. The project is unique in being the largest study of biological affinity in Mesoamerica using both metric and non-metric dental data, and the first to record cemento-enamel junction (CEJ) and crown measurements on all individuals. The intellectual merits of the study stem from its contribution to advance our current understanding of pan-regional interaction in Mesoamerica, as well as adding to the current literature on the agreement between crown and CEJ measurements.The broader impacts of the project are its contribution to research on an important period of Mesoamerican history. Additionally, researchers will be able to access raw, not summary data, from approximately 3,500 individuals for comparison with their own data or for additional statistical applications of these data.