Abstract
The Demographic Buffering Hypothesis (DBH) predicts that natural
selection reduces the temporal fluctuations in demographic processes
(such as survival, development, and reproduction), due to their negative
impacts on population dynamics. However, a comprehensive approach that
allows for the examination of demographic buffering patterns across
multiple species is still lacking. Here, we propose a three-step
framework aimed at quantifying demographic buffering. Firstly, we
categorize species along a continuum of variance based on the sums of
stochastic elasticities. Secondly, we examine the linear selection
gradients, followed by the examination of nonlinear selection gradients
as the third step. With these three steps, our framework overcomes
existing limitations of conventional approaches to quantify demographic
buffering, allows for multi-species comparisons, and offers insight into
the evolutionary forces that shape demographic buffering. We apply this
framework to mammal species and discuss both the advantages and
potential of our framework.