Data from: Genetic, maternal, and environmental influences on sociality in a pedigreed primate population

Various aspects of sociality in mammals (e.g., dyadic connectedness) are linked with measures of biological fitness (e.g., longevity). How within- and between-individual variation in relevant social traits arises in uncontrolled wild populations is challenging to determine but is crucial for understanding constraints on the evolution of sociality. We use an advanced statistical method, known as the ‘animal model’, which incorporates pedigree information, to look at social, genetic, and environmental influences on sociality in a long-lived wild primate. We leverage a longitudinal database spanning 20 years of observation on individually recognized white-faced capuchin monkeys (Cebus capucinus imitator), with a multi-generational pedigree. We analyze two measures of spatial association, using repeat sampling of 376 individuals (mean: 53.5 months per subject, range: 6-185 months per subject). Conditioned on the effects of age, sex, group size, seasonality , and El Niño–Southern Oscillation phases, we show low to moderate long-term repeatability (across years) of the proportion of time spent social (posterior mode [95% Highest Posterior Density interval]: 0.207 [0.169, 0.265]) and of average number of partners (0.144 [0.113, 0.181]) (latent scale). Most of this long-term repeatability could be explained by modest heritability (h2social: 0.152 [0.094, 0.207]; h2partners: 0.113 [0.076, 0.149]) with small long-term maternal effects (m2social: 0.000 [0.000, 0.045]; m2partners: 0.000 [0.000, 0.041]). Our models capture the majority of variance in our behavioral traits, with much of the variance explained by temporally changing factors, such as group of residence, highlighting potential limits to the evolvability of our trait due to social and environmental constraints.

哺乳动物社会性的多个维度（例如，二元关联度）均与生物适合度指标（例如，寿命）存在关联。在未受控制的野生种群中，相关社会性性状的个体内与个体间变异的成因难以确定，但这对于理解社会性演化的限制因素至关重要。我们采用一种名为动物模型（animal model）的先进统计方法，该方法整合了谱系信息，用以探究一种长寿野生灵长类动物社会性所受的社会、遗传与环境影响。我们依托一项横跨20年的纵向观测数据库，该数据库针对经个体识别的白面卷尾猴（Cebus capucinus imitator）开展追踪，且包含多代谱系信息，共纳入376只个体的重复采样数据（每只个体的平均观测时长为53.5个月，观测时长区间为6至185个月），以此分析两种空间关联指标。在控制年龄、性别、群体规模、季节性以及厄尔尼诺-南方涛动（El Niño–Southern Oscillation）相位等效应后，我们发现社交时间占比（潜在尺度下的后验众数[95%最高后验密度区间]：0.207 [0.169, 0.265]）与平均社交伙伴数（0.144 [0.113, 0.181]）均存在低至中等程度的长期（跨年度）可重复性。上述长期可重复性大多可通过适度的遗传力（h2social: 0.152 [0.094, 0.207]; h2partners: 0.113 [0.076, 0.149]）得到解释，同时伴随微弱的长期母体效应（m2social: 0.000 [0.000, 0.045]; m2partners: 0.000 [0.000, 0.041]）。我们的模型能够解释行为性状的大部分方差，其中大量方差可由居住群体等随时间变化的因素所解释，这凸显了社会性状演化能力因社会与环境限制而存在的潜在局限。