Doctoral Dissertation Research: Doctoral Dissertation Research: Reconstructing metabolism and physiology through analysis of transition metal isotopes

在现存和化石物种的骨骼中测量了几种具有特定化学特征或同位素的不同元素，以帮助研究人员重建有关饮食、迁徙和繁殖的信息。对过渡金属如锌、铁和铜的稳定同位素的测量也可以应用于活的或化石的灵长类动物骨骼的研究，以提供对这些因素的额外见解。该项目测量了灵长类动物个体骨骼中的过渡金属同位素，并将它们与这些个体一生中已知的信息联系起来，以更好地理解这些标记如何帮助从骨骼化石中重建有关肉类消费和婴儿喂养模式的信息。这个项目的结果还提供了关于新陈代谢的个体和性别差异如何影响这些测量的信息。这是一个多机构合作项目，包括指导来自STEM中代表性不足群体的本科生，社区外展以及向当地学校进行演讲。本研究有三个主要目的：1)牙釉质生物磷灰石和骨骼中的δ66Zn值是否记录了灵长类动物的哺乳和断奶模式？2)不经常食用肉类对生物磷灰石中δ66Zn值有何影响？3)在灵长类动物中是否存在与性别相关的铁和铜分离差异？雌性生殖投资的程度是否会影响这些值？分析方法包括使用质谱的过渡同位素分析，以及应用逻辑回归与机器学习算法来预测样本的饮食类别（果/草食或杂食/肉类消费）和营养位置。过渡金属（Zn, Fe, Cu）在有机保存较差的史前甚至化石骨骼元素中具有指示营养地位（δ66Zn）、性别和生殖状态（δ56Fe和δ65Cu）的潜力。本研究旨在建立一个非人类灵长类动物的参考数据集，作为该技术在野生灵长类动物中的首次应用，有可能极大地扩大过渡金属在考古科学中的应用。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。

Several different elements with specific chemical signatures, or isotopes, have been measured in bones of living and fossil species to help researchers reconstruct information regarding diet, migration, and reproduction. The measurement of stable isotopes of transition metals such as zinc, iron, and copper, could also be applied to the study of living or fossil primate bone to provide additional insight into these factors. This project measures transition metal isotopes in bone from primate individuals, and links them to information known from these individuals during life, to better understand how these markers might help reconstruct information about meat consumption and infant feeding patterns from fossilized bone. The results of this project also provide information about how individual- and sex-specific differences in metabolism influence these measurements. This is a multi-institutional collaborative project that includes mentoring of undergraduate students from groups underrepresented in STEM, community outreach, and presentations to local schools.This research has three main aims: 1) Are the breastfeeding and weaning patterns of primates recorded by δ66Zn values in enamel bioapatite and bone? 2) How does infrequent meat consumption affect the δ66Zn values measured in bioapatite? 3) Do sex- related differences in Fe and Cu fractionation occur in primates and does the degree of female reproductive investment affect these values? Analytic approaches include transition isotope analysis using mass spectrometry, and the application of a logistic regression with a machine learning algorithm to predict diet category (frugivorous/herbivorous or omnivorous/meat consuming) and trophic position of the samples. Transition metals (Zn, Fe, Cu) have the potential to be indicators of trophic position (δ66Zn), sex and reproductive state (δ56Fe and δ65Cu) in prehistoric and even fossil skeletal elements with poor organic preservation. This study aims to establish a reference dataset for nonhuman primates that serves as the first application of this technique in wild primates, with the potential to dramatically expand the use of transition metals in archaeological science.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.