WK 5

Individual Stochasticity: How to Model, Measure, and Interpret It

Individual stochasticity is random variability in the demographic fates of individuals (e.g., individual longevity, or lifetime reproductive success). It creates demographic variation even among identical individuals subject to identical vital rates at every point in the life cycle. It is thus an alternative to the explanation of individual variation as due to heterogeneity among the individuals.  Models for individual stochasticity can provide a null model to compare with explanations based on heterogeneity. This requires tools for calculating individual stochasticity from basic demographic data.  Recent developments have provided a powerful and general solution to this problem, and this workshop will teach these methods. They are based on Markov chain theory, and apply to models with arbitrary stage classifications, in constant or variable environments. The workshop assumes familiarity with basic matrix population models and equally basic statistical concepts.  A laptop with Matlab or R will make it possible to try some calculations, but this is not required.