Collaborative Research: Coupling Archaeological shell and novel isotope approaches to reconstruct impact of nearshore productivity change

考古学中的一个中心问题是了解人类如何受到过去环境变化的影响，以及他们如何反过来积极地塑造他们周围的生态系统和有机体。为了探索这些问题，一些考古学家试图了解人口稠密的沿海地区等级社会政治制度的起源。根据对文物、村庄结构、人类生存和高精度气候记录的分析，考古学家严格地辩论了假设的海洋生产力下降和延长的厄尔尼诺条件与长期干旱的影响。即使在世界上有极高分辨率的海洋气候记录的情况下，在整个区域的表层海洋学高度可变的情况下，解释过去的气候数据也可能是令人难以置信的挑战。该项目为几名本科生和研究生提供培训机会，特别是历史上代表性不足的群体和土著社区的成员，并将支持各种外联活动。这项研究试图了解这样一个区域何时以及为什么会出现文化复杂性，以及它可能与过去气候变化有任何联系。为了解决这些问题，研究人员利用从考古遗址获得的贝壳中的新型分子/同位素(氨基酸的化合物特定同位素或CSI-AA)进行分析。CSI-AA在考古贝壳中保存完好，可以直接记录当地海洋学中与气候有关的变化，包括营养来源、基线初级生产力、营养结构和藻类群落组成。这一分析提供了过去气候变化和环境生产力的一个新的、高度本地化的来源，以帮助解决中心研究问题。该项目是CSI-AA分析的首次系统考古应用，涉及加州广泛的社会、政治和文化发展，并将对世界各地过去环境变化的考古研究产生深远影响。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

A central issue in archaeology is understanding how people were influenced by past environmental change and how they, in turn, actively shaped ecosystems and organisms around them. To explore those questions, some archaeologists have attempted to understand the origins of hierarchical sociopolitical systems among the densely populated coastal regions. Drawing on the analysis of artifacts, village structure, human subsistence, and high-precision climate records, archaeologists have rigorously debated the impact of hypothesized declines in marine productivity and extended El Niño conditions vs. extended drought. Even in contexts with exceptionally high-resolution marine climate records in the world, interpreting past climatic data can be incredibly challenging where surface oceanography across the region is highly variable. This project provides training opportunities for several undergraduate and graduate students, especially members of historically under-represented groups and Indigenous communities, and will support a wide variety of outreach activities.This research seeks to understand when and why cultural complexity arose along one such region and any links it may have to past changes in climate. To address these issues, the researchers draw on the analysis of novel molecular/isotopes (compound-specific isotopes of amino acids or CSI-AA) in shells obtained from archaeological sites. CSI-AA is well preserved in archaeological shell and can directly record climate-linked shifts in local oceanography, including nutrient sources, baseline primary production, trophic structure, and algal community composition. This analysis offers a new, highly localized source of past climate variation and environmental productivity to help address the central research questions. This project is the first systematic archeological application of CSI-AA analyses addressing broad social, political, and cultural developments in California and will have far reaching implications for archaeological research on past environmental change around the world.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.