“Nothing in biology makes sense except in the light of evolution” (Dobzhansky, 1973). This module will demonstrate the use of a common set of fundamental principles about the origins and maintenance of heritable phenotypic variation to study how populations respond to environmental heterogeneity and change. This framework is extended to considering how new traits and species arise, and the consequences of evolutionary arms races within and between species. The module is taught by a team of academics who are actively researching these problems, through lectures and interactive workshops which will give students the opportunity to discuss concepts and practice problem solving. The assessment consists of a data analysis/interpretation report and an open question essay.