Mechanisms and Consequences of Social Connectedness in a Wild Primate Population

描述（由申请人提供）：对野生动物种群衰老的研究，特别是对我们的灵长类近亲的研究，为理解人类衰老的过程和模式提供了一套独特的潜在益处。动物模型提供的比较视角既可以揭示控制物种衰老过程的一般原理和机制，也可以突出人类特有的衰老特征。此外，在某些情况下，在人类中极难收集的数据集（如自然社会环境中精细的行为数据）在野生灵长类动物种群中更容易获得。然而，尽管人们对衰老作为一种人类健康问题有着浓厚的兴趣，并且近几十年来在这一领域取得了巨大进展，但野生动物的衰老模式——与年龄相关的变化不仅在生存方面，而且在社会行为、激素谱和健康和功能的其他方面——仍然几乎完全没有被描述出来。我们从肯尼亚南部的野生狒狒种群中获得的详细的纵向数据提供了明确的证据，证明衰老是会发生的，而且个体之间在寿命和功能衰退方面都存在相当大的差异。狒狒生活在稳定的社会群体中，群体内的个体共享共同的环境，因此身体和人口统计学上的差异不能单独解释在衰老过程和寿命中观察到的差异。然而，个体社会关系的质量和稳健性在个体之间确实存在差异，无论是在社会群体内部还是在社会群体之间，这种差异对狒狒的生理和功能都有影响。这些结果使社会连通性成为我们正在进行的、对这一人群终生结果差异的综合分析的重点，并为详细研究社会连通性的动态及其与老龄化的关系奠定了基础。本研究的目标是确定老龄化背景下社会联系的组成部分、生理相关性和后果，并确定社会联系变异的遗传和环境来源。我们将测试这样的假设，在野生非人类灵长类动物和人类中，社会联系是整个生命过程中健康和幸福的一个预测因素；这种效应与密度无关；这种社会联系随着年龄的增长而下降。然后，我们将研究一组已知生物学途径中的遗传变异与社会联系表型之间的关系。最后，我们将使用时间序列模型将遗传变异和环境变异的影响整合到生命周期方法中。我们会问，发生在生命早期阶段的影响是否会影响到晚年，或者晚年的社会联系是否是一种相对独立的现象。这种分析将有助于确定在生命过程中预测和/或干预与衰老相关的结果可能最富有成效的阶段。

DESCRIPTION (provided by applicant): Studies of aging in wild animal populations, especially in our primate relatives, offer a unique set of potential benefits for understanding the processes and patterns governing human aging. The comparative perspective that animal models provide can both bring to light general principles and mechanisms that govern the aging process across species, and can highlight human-specific characteristics of aging. Additionally, in some cases datasets that are extremely difficult to gather in humans (such as fine-scaled behavioral data in natural social settings) are more readily obtainable in wild primate populations. However, despite keen interest in aging as a human health concern and the enormous progress in this area in recent decades, patterns of aging in wild animals - age-related changes not just in survival, but also in social behavior, hormone profiles, and other aspects of health and functioning - remain almost entirely undescribed. Our detailed, longitudinal data from a population of wild baboons in southern Kenya provides clear evidence both that senescence occurs, and that considerable variance among individuals is seen both in lifespan and in functional declines with age. Baboons live in stable social groups, and individuals within groups share common environments, so physical and demographic differences alone cannot account for the observed variance in the aging process and in lifespan. However, the quality and robustness of individual social relationships do vary among individuals, both within and between social groups, and this variation has both physiological and functional consequences for baboons. These results have brought social connectedness to the foreground in our ongoing, integrative analysis of variance in lifetime outcomes in this population, and have set the stage for a detailed investigation of the dynamics of social connectedness and its relationship to aging. The goals of the proposed work are to identify the components, physiological correlates, and consequences of social connectedness in the context of aging, and to identify genetic and environmental sources of variance in social connectedness. We will test the hypotheses that, in wild nonhuman primates as in humans, social connectedness is a predictor of health and well being throughout the life course; that this effect is independent of density; and that social connectedness declines with age. We will then investigate the relationship between genetic variation in a set of known biological pathways and social connectedness phenotypes. Finally, we will integrate the effects of genetic variation and environmental variation into a life span approach, using a time-series model. We will ask whether the effects that occur in earlier stages of life propagate into late life, or if social connectedness in late life is a relatively independent phenomenon. This analysis will aid in identifying stages during the life course in which prediction of and/or intervention in aging- related outcomes may be most fruitful. PUBLIC HEALTH RELEVANCE: The proposed research will investigate health and well being during aging in a natural population of wild primates, which are closely related to humans and share key similarities, but also important differences. The research will specifically examine the contribution of social connectedness to aging-related outcomes in a natural setting, as well as the genetic and environmental contributors to social connectedness itself. This will offer potential benefits for human health by illuminating important opportunities for, and constraints on, alleviating age- related declines in human health and survival.