Ehleringer James R, Bowen Gabriel J, Chesson Lesley A, West Adam G, Podlesak David W, Cerling Thure E
IsoForensics, Inc., 423 Wakara Way, Suite 205, Salt Lake City, UT 84108, USA.
Proc Natl Acad Sci U S A. 2008 Feb 26;105(8):2788-93. doi: 10.1073/pnas.0712228105. Epub 2008 Feb 25.
We develop and test a model to predict the geographic region-of-origin of humans based on the stable isotope composition of their scalp hair. This model incorporates exchangeable and nonexchangeable hydrogen and oxygen atoms in amino acids to predict the delta(2)H and delta(18)O values of scalp hair (primarily keratin). We evaluated model predictions with stable isotope analyses of human hair from 65 cities across the United States. The model, which predicts hair isotopic composition as a function of drinking water, bulk diet, and dietary protein isotope ratios, explains >85% of the observed variation and reproduces the observed slopes relating the isotopic composition of hair samples to that of local drinking water. Based on the geographical distributions of the isotope ratios of tap waters and the assumption of a "continental supermarket" dietary input, we constructed maps of the expected average H and O isotope ratios in human hair across the contiguous 48 states. Applications of this model and these observations are extensive and include detection of dietary information, reconstruction of historic movements of individuals, and provision of region-of-origin information for unidentified human remains.
我们开发并测试了一个基于人类头皮毛发稳定同位素组成来预测其地理起源区域的模型。该模型纳入了氨基酸中可交换和不可交换的氢原子与氧原子，以预测头皮毛发（主要是角蛋白）的δ(2)H和δ(18)O值。我们通过对来自美国65个城市的人类毛发进行稳定同位素分析来评估模型预测。该模型将毛发同位素组成预测为饮用水、总体饮食和膳食蛋白质同位素比率的函数，解释了超过85%的观测变异，并重现了观测到的毛发样本同位素组成与当地饮用水同位素组成之间的斜率关系。基于自来水同位素比率的地理分布以及“大陆超市”膳食输入的假设，我们绘制了美国本土48个州人类毛发中预期平均氢和氧同位素比率的地图。该模型及这些观测结果的应用广泛，包括检测饮食信息、重建个人历史移动轨迹以及为身份不明的人类遗骸提供起源区域信息。
