Doctoral Dissertation Improvement: Variation in Macaque Social Structure from Phylogenetic, Socioecological and Biological Markets Principles

非人灵长类动物的社会结构在物种内和物种之间都有明显的差异。尽管没有达成共识，但已经提出了几种解释。其中之一是，社会结构根据物种过去的祖先关系(系统发育亲缘关系)而变化。另有两个基于这样的观点，即当前生态因素的变化(例如，群体规模和/或食物分布)塑造了同一物种群体内部和群体之间的竞争模式，进而塑造了(1)与竞争和优势相关的行为的结构，和/或(2)由经济模型(例如，供需)预测的附属行为的交换模式(例如，梳理、攻击性支持)。博士研究生Krishna Balasubramaniam(水牛城大学)在Carol Berman博士的指导下，测试了与这些解释相关的预测，重点是灵长类猕猴的雌性。研究人员将重建系统发育树以破译祖先关系，并使用这些树来确定九个猕猴物种之间与优势相关行为的差异是否与遗传相关程度有关。为了测试物种内的解释，他们将收集波多黎各卡约圣地亚哥自由放养的恒河猴的观察行为数据，使用重点动物和所有事件抽样。将对这些数据进行各种统计分析，以测试群体规模和竞争能力的经验测量是否随着攻击行为的模式和/或附属行为的交换而变化。这项研究在测试与单一研究中对非人类灵长类社会结构变化的多种解释有关的预测方面是独一无二的。它阐明了物种的祖先关系与当前生态条件的变化在塑造猕猴社会行为方面的相对贡献，并解决了目前关于物种固有特征和/或稳定的环境影响与灵长类动物(包括早期人类)对当前条件的适应的相对作用的争论。此外，与关联行为交换模式相关的研究方面对理解人类经济行为具有重要意义。

Social structure in nonhuman primates varies markedly both within and between species. Although there is no consensus, several explanations have been proposed. One is that social structure varies in accordance with species' past ancestral relationships (phylogenetic closeness). Two others are based on the idea that variation in current ecological factors (e.g., group size and/or food distribution) shapes patterns of competition within and between groups of the same species, and in turn, shapes (1) the structure of agonistic and dominance-related behavior, and/or (2) patterns of exchange of affiliative behavior (e.g., grooming, aggressive support) that occur as predicted by economic models (e.g., supply-and-demand). Research by doctoral student Krishna Balasubramaniam (University at Buffalo), supervised by Dr. Carol Berman, tests predictions related to these explanations, focusing on females in the primate genus Macaca. The investigators will reconstruct phylogenetic trees to decipher ancestral relationships, and use these to determine whether variation in dominance-related behavior across nine macaque species correlates with degrees of genetic relatedness. To test within-species explanations, they will collect observational behavioral data on free-ranging rhesus macaques at Cayo Santiago, Puerto Rico, using focal-animal and all-occurrences sampling. Various statistical analyses will be applied to these data to test whether group sizes and empirical measures of competitive ability vary with patterns of aggressive behavior, and/or the exchange of affiliative behaviorThe research is unique in testing predictions related to multiple explanations for variation of nonhuman primate social structure in a single study. It sheds light on the relative contributions of species' ancestral relationships vs. variation in current ecological conditions in shaping macaque social behavior, and addresses current debates concerning the relative roles of inherent species characteristics and/or stable environmental influences vs. adaptation to current conditions across primates, including early humans. In addition, aspects of the study related to patterns of exchange of affiliative behavior have important implications for understanding human economic behavior.