Bridging Paleolimnology And Archaeology Through Human Biomarkers In Lake Sediment

了解随着时间推移的人口水平对于回答关于遥远过去的许多问题是至关重要的。例如，不断上升的人口水平是否刺激了重大的社会变革，如农业的采用、更复杂的社会和政治等级制度，或者加剧的战争？人口水平如何受到新地区殖民、环境危机或国家崩溃等重大事件的影响？传统上，考古学家通过考古调查来估计过去的人口结构，但这并不总是可能的(例如，对于人口密度低、流动性高的人类住区阶段，或者在由于茂密的植被或冲积沉积而导致遗址表面能见度较低的地区)。这个跨学科的项目旨在确定最近在古代湖泊沉积物中定义的生化标记物是否可以作为一段时间内人类种群水平的可靠指标。P.I.伊丽莎白·阿尔库什博士、联合P.I.约瑟夫·韦恩博士和共同PI马克·阿博特博士将利用国家科学基金会的支持，对秘鲁南部的喀喀湖盆地的湖泊沉积物进行取芯和分析的试点季节。如果成功，这项技术将在重建地区人口历史方面拥有巨大的潜力。此外，由于湖泊岩心序列还具有其他重要信息，如降雨量，这项技术通过减少匹配单独的气候和人口记录所带来的年代学不确定性，有望研究人类种群和环境变化之间的关系。最近的研究表明，来自高等哺乳动物粪便的有机化合物5-烷醇在湖泊沉积物中以可测量的数量存在。存在和数量应反映湖泊分水岭中的人口水平，特别是作为人类粪便中主要的5-“-甾醇的辅前列醇。该项目旨在通过将安第斯山脉中南部两个湖芯中的5-“-烷醇与已经完成的两次全面考古调查得出的种群水平序列进行比较，来评估和扩大这一生物标记物在考古研究中的用途。除了推进重建过去人口学的新方法外，由此产生的数据集还有可能在哥伦布之前的社会政治变化与古气候之间的联系问题上取得重大进展。该项目的更广泛影响包括为本科生和研究生提供大量的培训和研究机会。

Understanding human population levels over time is fundamentally important for answering numerous questions about the deep past. For instance, were rising population levels responsible for spurring major social transformations, like the adoption of agriculture, more complex social and political hierarchies, or intensified warfare? How were population levels affected by major events like the colonization of new areas, environmental crises, or the collapse of states? Traditionally, archaeologists arrive at estimates of past demography through archaeological survey, but this is not always possible (e.g., for phases of human settlement with low population densities and high mobility, or in regions with poor surface visibility of sites due to thick vegetation or alluvial deposition). This interdisciplinary project aims to establish whether recently defined biochemical markers in ancient lake sediment can serve as reliable proxies for human population levels over time. P.I. Dr. Elizabeth Arkush, Co-P.I. Dr. Josef Werne, and Co-PI Dr. Mark Abbott will use National Science Foundation support for a pilot season of coring and analysis of lake sediments from the Titicaca Basin of southern Peru. If successful, this technique will hold major potential for reconstructing the demographic histories of regions. In addition, because lake core sequences also have other significant information such as precipitation levels, this technique holds promise for investigating the relationship between human populations and environmental change by reducing the chronological uncertainty that comes from matching separate climate and population records.Recent research shows that fecal 5-Ò-stanols, organic compounds deriving from feces of higher mammals, are present in measurable amounts in lake sediments. The presence and quantity should reflect human population levels in the lake watershed, particularly coprostanol, which is the major 5-Ò-stanol in human feces. This project aims to evaluate and expand the utility of this biomarker for archaeological research by comparing 5-Ò-stanols in two lake cores in the south-central Andes with sequences of population levels derived from two already completed full-coverage archaeological surveys. In addition to advancing new methodology for the reconstruction of past demography, the resulting dataset has the potential to make significant advances on questions about the connection between pre-Columbian sociopolitical change and paleoclimate. The project's broader impacts include significant training and research opportunities for undergraduate and graduate students.