Dietary Reconstruction with Stable Isotopes

由于饮食和消费者组织的化学成分之间存在关系，古人类学家将注意力集中在对人类骨骼残骸的化学分析上。通过对锶等微量元素以及碳和氮的同位素比率的研究，往往有可能洞察一个人一生中消费的食物。在大多数考古发掘中，由于保存不佳，食物遗迹--特别是植物食物--没有出现，因此，骨骼分析提供了重建生存的唯一手段。虽然在实践中，这些技术似乎工作得很好，但人们对元素被结合到骨骼等组织中的确切机制知之甚少，如果没有这样的知识，就很难高度依赖这些研究的结果。Stanley Ambrose博士和他的同事们将继续他们的工作，以阐明这些机制。他们将进行由一系列实验组成的综合研究计划。其中包括11项控制饮食实验，使用小型哺乳动物在不同的模拟环境条件下以不同的组合喂食自然标记的碳水化合物和蛋白质。这将定义饮食的稳定同位素组成、饮食的生化部分和消费者组织之间的关系。它还将深入了解蛋白质营养对胶原和磷灰石周转率的影响。该团队还将分析自然环境中六个人的头发的同位素组成，这些人的饮食在纵向营养研究中得到了准确的量化。这将为评价实验室实验结果提供一个实际情况。如果时间允许，还将检查史前人口的骨骼样本。这项研究很重要，因为它将增加我们对营养过程的基本了解。它将产生在广泛的考古情况下使用的分析方法。

Because a relationship exists between diet and the chemical composition of the consumer's tissue, paleoanthropologists have focussed attention on the chemical analysis of human skeletal remains. Through study of trace elements such as strontium and the isotopic ratios of carbon and nitrogen, it is often possible to gain insight into foods consumed during an individual's lifetime. In most archaeological excavations food remains - especially plant foods - are absent because of poor preservation, and, therefore, skeletal analysis provides the only means to reconstruct subsistence. While, in practice, these techniques seem to work well, the exact mechanisms by which elements are incorporated into tissue such as bone are poorly understood, and without such knowledge, it is difficult to place a high degree of reliance on the results of such studies. Dr. Stanley Ambrose and his colleagues will continue their work to elucidate these mechanisms. They will conduct an integrated program of research comprising a series of experiments. These include eleven controlled diet experiments using small mammals fed naturally labeled carbohydrates and proteins in different combinations under different simulated environmental conditions. This will define the relationship between the stable isotopic composition of diet, biochemical fractions of diet, and consumer tissues. It will also provide insight into the effects of protein nutrition on collagen and apatite turnover rate. The team will also analyze the isotopic composition of hair of six human populations in natural environments whose diets have been accurately quantified in longitudinal nutrition study. These will provide a practical situation in which to evaluate the results of the laboratory experiments. If time is available, bone samples from prehistoric populations will also be examined. This research is important because it will increase our basic understanding of the nutritional process. It will yield analytic approaches of use in a wide variety of archaeological situations.