Mechanisms and Consequences of Social Connectedness in a Wild Primate Population

描述(申请人提供)：研究野生动物种群的衰老，特别是在我们的灵长类近亲中，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支配跨物种衰老过程的一般原则和机制，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(如自然社会环境中的精细行为数据)更容易在野生灵长类种群中获得。然而，尽管近几十年来人们对衰老作为人类健康问题产生了浓厚的兴趣，并在这一领域取得了巨大进展，但野生动物的衰老模式-不仅在生存方面，而且在社会行为、激素谱以及健康和功能的其他方面-仍然几乎完全没有描述。我们详细的、纵向的数据来自肯尼亚南部的一个野生狒狒种群，我们提供了明确的证据，表明衰老是发生的，而且个体之间在寿命和功能随年龄下降方面都有相当大的差异。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，因此仅凭身体和人口统计学的差异不能解释观察到的老龄化过程和寿命的差异。然而，个体社会关系的质量和稳定性确实因个体不同而不同，无论是在社会群体内部还是在社会群体之间，这种差异对狒狒都有生理和功能上的影响。这些结果将社会联系带到了我们正在进行的对这一人群一生结果差异的综合分析的前景中，并为详细调查社会联系的动态及其与老龄化的关系奠定了基础。这项拟议工作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，并确定社会联系差异的遗传和环境来源。我们将测试以下假设：在野生非人类灵长类动物中，就像在人类中一样，社会联系是整个生命过程中健康和幸福的预测指标；这种影响独立于密度；以及社会联系随着年龄的增长而下降。然后，我们将调查一组已知生物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寿命方法中。我们会问，发生在生命早期阶段的影响是否会传播到晚年，或者晚年的社会联系是否是一个相对独立的现象。这一分析将有助于确定在生命过程中预测和/或干预衰老相关结果可能最有成效的阶段。 公共卫生相关性：这项拟议的研究将调查自然种群野生灵长类动物在老龄化过程中的健康和幸福感，这些动物与人类密切相关，有关键的相似之处，但也有重要的区别。这项研究将具体考察社会联系对自然环境中与老龄化相关的结果的贡献，以及遗传和环境因素对社会联系本身的贡献。这将为人类健康提供潜在的好处，因为它揭示了缓解与年龄相关的人类健康和存活率下降的重要机会和制约。

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.