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

考古学的一个核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塑造周围的生态系统和生物体。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。通过对文物、村庄结构、人类生存和高精度气候记录的分析，考古学家们对假设的海洋生产力下降和厄尔尼诺现象持续与干旱持续的影响进行了严格的辩论。即使在世界上有非常高分辨率的海洋气候记录的情况下，解释过去的气候数据也是非常具有挑战性的，因为整个地区的表层海洋学变化很大。该项目为一些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，并将支持各种各样的外联活动。这项研究旨在了解文化复杂性何时以及为什么出现在沿着这样一个地区，以及它可能与过去气候变化的任何联系。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（氨基酸或CSI-AA的化合物特异性同位素）的分析。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相关的变化，包括营养来源，基线初级生产，营养结构和藻类群落组成。这项分析提供了一个新的，高度本地化的来源，过去的气候变化和环境生产力，以帮助解决中心的研究问题。该项目是第一个系统的考古应用CSI-AA分析解决广泛的社会，政治和文化发展在加州，并将有深远的影响考古学研究过去的环境变化在世界各地。这个奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

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.