Eco-evolutionary feedback between genetic diversity and population sizes in variable environments

Small populations are often strongly affected by genetic drift, demographic stochasticity and often also by changing environmental conditions. My main objective is to understand:

(a) how genetic variation can be maintained in populations living in temporally variable environments,

(b) how much genetic variation is needed for small populations to escape extinction, and

(c) what eco-evolutionary feedback can be obtained between population sizes and genetic variation. Mathematical models with fluctuations in both selection pressures and population sizes will be constructed. The model results will then be applied to suitable empirical data.