Collaborative Research: Hard Tissue evidence of weaning variation in primates

断奶（停止母乳喂养）是一个重要的发育里程碑，对产妇生殖策略和婴儿结局具有重要影响。现代人类平均比类人猿更早断奶，但这种独特的人类模式的进化起源还不清楚。这个跨学科的研究项目将研究三种不同野生类人猿的行为、生态、生理和发育数据，以了解比较灵长类动物框架中断奶变异的来源。该项目将产生一个更全面的了解断奶变化的生物，生态和社会相关性在我们最近的生活亲属使用的方法，是可翻译到古生物学背景，从而有助于理解人类断奶的进化框架。 该项目将通过为学生和早期职业科学家提供结构化实习、指导和其他强化培训机会，扩大代表性不足群体对科学的参与。研究基础设施将通过建立与灵长类动物保护和人类进化生物学交叉领域的许多问题相关的新的合作和跨学科数据集来加强。 这项工作的结果将推进我们对这些极度濒危猿类的种群动态和健康的理解，并将传达给野生动物兽医和公园管理人员，以告知保护策略，以及通过在线和其他公共场所。断奶的时间代表了母亲和后代进化利益的平衡，对生理限制以及物理和社会环境敏感。然而，生活灵长类动物的行为观察不能区分营养与社会功能的护理，重建断奶在古生物学背景下的方法是有限的，他们的能力，以区分断奶之间的变化密切相关的类群。野生类人猿断奶变化的比较和多代理研究集中在三个生态不同的种群，表现出明显的变化，在哺乳行为和母亲的生殖策略：维龙加和布温迪山地大猩猩，这在生态上有显着差异，和贡贝黑猩猩，这提供了一个重要的分类对比。该项目整合了哺乳和喂养行为，身体发育，以及从生活中的个体收集的粪便稳定同位素数据，其食物的化学特征，以及这些人群死后相关骨骼的形态和牙齿微量元素分析。这项研究调查了（1）哪些因素影响了野生黑猩猩和大猩猩断奶相关饮食转变的变化，（2）生物组织中的化学物质是如何影响断奶相关饮食转变的？（粪便，牙齿）与断奶的行为和解剖学代表有关，以及（3）牙科微量元素如何可靠地记录个人和人群饮食史的变异性。该奖项反映了NSF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。

Weaning (cessation of breastfeeding) is a critical developmental milestone with important consequences for maternal reproductive strategies and infant outcomes. Modern humans wean their young much earlier on average than the great apes, but the evolutionary origins of this uniquely human pattern are not well understood. This interdisciplinary research project will study behavioral, ecological, physiological, and developmental data for three different wild great ape species, to understand sources of weaning variation in a comparative primate framework. The project will generate a more comprehensive understanding of the biological, ecological and social correlates of weaning variation in our closest living relatives using approaches that are translatable to paleontological contexts, thus contributing to a framework for understanding the evolution of weaning in humans. This project will broaden participation of underrepresented groups in science through structured internships, mentoring and other enhanced training opportunities for students and early career scientists. Research infrastructure will be enhanced by establishing new collaborations and interdisciplinary datasets relevant to many questions at the intersection of primate conservation and human evolutionary biology. Results of this work will advance our understanding of the population dynamics and health of these critically endangered apes, and will be communicated to wildlife veterinarians and park managers to inform conservation strategies, as well as through online and other public venues.The timing of weaning represents a balance of maternal and offspring evolutionary interests, and is sensitive to physiological constraints as well as physical and social environments. However, behavioral observations of living primates cannot distinguish nutritive versus social functions of nursing, and methods for reconstructing weaning in paleontological contexts are limited in their ability to discriminate weaning variation among closely-related taxa. This comparative and multi-proxy study of weaning variation in wild great apes focuses on three ecologically-distinct populations that show pronounced variation in suckling behavior and maternal reproductive strategies: Virunga and Bwindi mountain gorillas, which differ markedly in ecology, and Gombe chimpanzees, which provide an important taxonomic contrast. This project integrates suckling and feeding behavior, physical development, and fecal stable isotope data collected from individuals in life, with chemical characterization of their foods, and morphological and dental trace element analyses of associated skeletons from these populations after death. This research investigates (1) what factors influence variability in weaning-related dietary transitions across living wild chimpanzees and gorillas, (2) how chemical proxies in biological tissues (fecal, dental) relate to behavioral and anatomical proxies of weaning, and (3) how reliably dental trace elements record variability in documented dietary histories at the individual and population levels.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.