Collaborative proposal: Tracing the Evolution of Late Quaternary Human Interaction and Mobility Patterns in Kenya

在国家科学基金会的支持下，Stanley Ambrose博士（伊利诺伊大学）和Jeffrey Ferguson博士，Michael McCock博士和大卫罗伯逊（密苏里州研究反应堆大学）将研究现代人类行为发展的最后阶段发生的关键转变。互惠、合作和信息共享已被证明是在各种实验和自然环境中生存的有利策略。 区域信息和物资交流网络是狩猎采集者在危险和不可预测的环境中生存的根本。 什么样的考古证据可以表明人类社会采取区域合作策略，这种转变发生在何时何地？远距离交换系统最持久和最丰富的证据是石器。 黑曜石是一种火山玻璃，在东非被广泛用于锋利的石器。 每个火山源都有不同的化学成分。 通过确定来自考古遗址的黑曜石文物的化学指纹，它们可以与它们的来源联系起来，从而可以揭示有关交换和区域社会互动模式的信息。考古发掘的结果表明，大约在6万至7万年前，东非的黑曜石文物出现频率大幅增加。这种变化与上一个冰河时代早期长期严重的环境退化相吻合。 类似的变化可能发生在非洲其他地区，但还不能通过人工制品的化学分析来验证。在欧亚大陆由尼安德特人建造的当代遗址中，来自遥远来源的石器原材料并没有出现类似的增长。这一证据表明，合作战略首先在非洲发展起来，以应对急剧的气候变化。 遗传学证据表明，东北非洲人在这一转变后从非洲扩张出来，取代了欧亚大陆的古老人口。 他们的合作策略可能是他们在最后一个冰河时代中期成功扩张的关键。 Ambrose博士和他的学生的大部分工作将涉及从已知来源采集黑曜石样本，以及对肯尼亚其他露头的调查。其余的实地工作将涉及从肯尼亚国家博物馆的藏品中挑选文物进行分析。将在密苏里州大学研究反应堆（穆尔）使用X-射线对数千件人工制品和源样品的化学成分进行分析。射线荧光和中子活化分析。这项研究将对社会和行为科学产生更广泛的影响，因为它将为气候变化在向现代人类过渡的最后阶段加强合作方面的作用提供有价值的证据。行为 它将促进对社会战略的理解，这些战略促进了我们后来从热带非洲向世界其他地区的成功扩张，以及尼安德特人的灭亡。 该项目还将影响该地区未来的研究，因为黑曜石来源参考数据库将有助于研究以后的时期。 最后，本研究将为野外地质学、考古学和地球化学与核化学实验室研究方法的研究生提供科学培训和教育机会。

With the support of the National Science Foundation, Dr. Stanley Ambrose (University of Illinois) and Drs. Jeffrey Ferguson, Michael Glascock, and David Robertson (University of Missouri Research Reactor) will examine a critical transition that occurred during the final stages of the development of modern human behavior. Reciprocity, cooperation and sharing of information have been demonstrated to be an advantageous strategy for survival in a variety of experimental and natural settings. Regional information and materials exchange networks are fundamental for survival of hunter-gatherers in risky, unpredictable environments. What kinds of archaeological evidence can show that human societies adopt regional cooperative strategies, and when and where did this transition occur? The most durable and abundant class of evidence for long distance exchange systems is stone tools. Obsidian is a volcanic glass that was widely used for sharp-edged stone tools in East Africa. Each volcanic source has a distinct chemical composition. By determining the chemical fingerprint of obsidian artifacts from archaeological sites they can be linked to their sources, and thus can reveal information about exchange and regional social interaction patterns. Results from archaeological excavations show that a substantial increase in frequencies of obsidian artifacts occurred approximately 60,000 to 70,000 years ago in East Africa. This change coincides with a long period of severe environmental degradation during the early the last ice age. Similar changes may have occurred in other parts of Africa at this time, but cannot yet be validated by chemical analysis of artifacts. Contemporary sites in Eurasia made by neandertals do not show an analogous increase in stone tool raw materials from distant sources. This evidence suggests that cooperative strategies developed first in Africa, in response to dramatic climate change. Genetic evidence demonstrates that northeast Africans expanded out of Africa and replaced archaic human populations in Eurasia after this transition. Their cooperative strategy may have been the key to their successful expansion during the middle of the last ice age. The majority of the work by Dr. Ambrose and his students will involve sampling obsidian from known sources as well as survey for additional outcrops in Kenya. The remainder of the fieldwork will involve selecting artifacts for analysis from collections in the National Museums of Kenya. Analysis of the chemical composition of several thousand artifact and source samples will be carried out at the University of Missouri Research Reactor (MURR) using X-ray fluorescence and Neutron Activation analysis.This study will have broader impacts for social and behavioral sciences because it will provide valuable evidence for the role of climate change in the development of enhanced cooperation during the final stages of the transition to modern human behavior. It will promote understanding of the social strategies that facilitated our subsequent success in expanding from tropical Africa to the rest of the world, and the demise of neandertals. This project will also impact future research in the region because the obsidian source reference database will be useful for studying later periods. Finally, this research will provide scientific training and education opportunities for graduate students in field geology, archaeology and laboratory research methods on geochemistry and nuclear chemistry.