Environmental stochasticity is a key determinant of population viability. Decades of work exploring how environmental stochasticity influences population dynamics have highlighted the ability of some natural populations to limit the negative effects of environmental stochasticity, one of these strategies being demographic buffering. Whilst various methods exist to quantify demographic buffering, we still do not know which environment factors and demographic characteristics are most responsible for the demographic buffering observed in natural populations. Here, we introduce a framework to quantify the relative effects of three key drivers of demographic buffering: environment components (e.g., temporal autocorrelation and variance), population structure, and demographic rates (e.g., progression and fertility). Using Integral Projection Models, we explore how these drivers impact the demographic buffering abilities of three plant species with different life histories and demonstrate how our approach successfully characterises a population’s capacity to demographically buffer against environmental stochasticity in a changing world.

Raisa Hernández-Pachecoa*, Ulrich K. Steinerb, Alexandra G. Rosatic, Shripad TuljapurkardaCalifornia State University-Long Beach, Department of Biological Sciences, 1250 N Bellflower Blvd, Long Beach, CA, USA 90840-0004bFreie Universität Berlin, Biological Institute, Königin-Luise Str. 1-3,14195 Berlin, Germany; cDepartments of Psychology and Anthropology, University of Michigan, 530 Church St, Ann Arbor, MI, USA 48109 d327 Campus Dr., Rm 233, Stanford University, Stanford, CA, USA 94305*Corresponding author:rai.hernandezpacheco@csulb.eduCompeting interests statement : None.Abstract . Several social traits including status, integration, early-life adversity, and their interactions across the life course can predict health, reproduction, and mortality in humans. Accordingly, individual sociality plays a fundamental role in the emergence of phenotypes driving the evolution of aging. Recent work placing human social gradients on a biological continuum with other species provides a useful evolutionary context for aging questions, but there is still a need for a unified evolutionary framework for sociality, health, and aging. Here, we first summarize current challenges to disentangle the effects of the social environment on human life courses. Next, we review recent advances in comparative biodemography and propose a biodemographic perspective to address socially driven health phenotype distributions and their evolutionary consequences using a nonhuman primate population. This new comparative approach uses evolutionary demography to address the joint dynamics of populations, sociality, phenotypes, and life history parameters. The long-term goal is to advance our understanding of the link between individual sociality, population-level outcomes, and the evolution of aging.