Doctoral Dissertation Improvement Award: Variability in Silcrete Heat Treatment Technology and Implications for Modern Human Behavior

本博士论文研究项目旨在更好地理解现代人类行为产生的生物、文化和环境背景。研究主要集中在复杂认知的出现和现代人类表现出的特殊形式的社会学习。考古学很好地提供了洞察力，因为它可以使用材料记录来分析跨越时间的大规模模式，以确定这些特征可能出现的时间、地点和背景。现代人类行为的一个重要但研究相对较少的代表是使用火来提高制作工具的石头的质量。这种技术被称为岩石热处理，被认为是通过类比推理识别和组合抽象概念能力的最早证据之一，可能需要社会学习和教学。这项研究提高了对过去的岩石热处理技术的理解，以及它与现代人类行为的演变以及可能的其他变革性技术（如铁匠和陶瓷）的关系。该项目为两名本科生提供石器分析、数据库管理和文物管理方面的培训。本项目通过实验考古学创建的第一个大规模热处理技术经验参考数据集的开发，研究了过去人类如何热处理石材原材料。这些数据有助于建立属性标准，并开发具有经验支持的新方法，以区分考古记录中的石器热处理方法。该团队开发了定量、概率、廉价和非破坏性的新方法，以提高其可复制性和普遍性。这些方法的考古应用主要集中在对南非南部海岸附近的三个中石器时代考古遗址（Pinnacle Point和Boomplaas Cave）的分析上，以确定从16.2万年前到4万年前的热处理方法是如何变化的。这些遗址对这项研究至关重要，因为它们保存了一些最早的岩石热处理技术的证据，并且具有与高分辨率的古环境和古生态记录相关的长而准确的序列。这使研究人员能够将中石器时代的人类如何在12.5万年的时间里对石头进行热处理，并确定这与现代人类行为的出现有何关系。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This doctoral dissertation research project seeks to better understand the biological, cultural, and environmental contexts out of which modern human behavior emerged. Research has focused heavily on the emergence of complex cognition and the special forms of social learning exhibited by modern humans. Archaeology is well placed to provide insight because it can use the material record to analyze large-scale patterns across deep time to determine when, where, and in what context these traits may have emerged. An important but relatively understudied proxy for modern human behavior is the use of fire to improve the quality of stone for toolmaking. This technology, known as lithic heat treatment, is thought to be some of the earliest evidence for the ability to recognize and combine abstract concepts through analogical reasoning and may require social learning and teaching. This research improves understanding of lithic heat treatment technology in the past and how it relates to the evolution of modern human behavior and possibly other transformative technologies such as blacksmithing and ceramics. The project provides training to two undergraduate students in stone tool analysis, database management, and artifact curation.This project examines how humans heat treated stone raw material in the past through the development of the first large-scale empirical reference dataset of heat treatment technology created through experimental archaeology. These data serve to establish attribute criteria and develop novel methods with empirical support for distinguishing between lithic heat treatment methods in the archaeological record. The team develops novel methods that are quantitative, probabilistic, inexpensive, and non-destructive to enhance its replicability and generalizability. The archaeological application of these methods focuses on the analysis of three Middle Stone Age archaeological sites near the south coast of South Africa – Pinnacle Point and Boomplaas Cave – to determine how methods of heat treatment varied from ~162,000 years ago to 40,000 years ago. These sites specifically, are critical to this research because they preserve some of the earliest evidence of lithic heat treatment technology and have long, well-dated sequences that are associated with high-resolution paleoenvironmental and paleoecological records. This allows the researchers to contextualize how Middle Stone Age humans were heat treating stone over ~125,000 years and to determine how this relates to the emergence of modern human behavior.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.