Thesis supervisor: Prof. Toomas Tammaru, University of Tartu
Opponent: Magne Friberg, PhD, Uppsala University, Sweden
The main goal of my thesis was to study reaction norms for size and age at maturity in insects. In particular, I aimed to describe reaction norms with different slopes and discuss environmental conditions that could be responsible for evolution of such differences. I summarized the reviewed literature to evaluate the relative frequency of negatively and positively sloped bivariate reaction norms and discuss the conditions inflicting those situations. Furthermore, I performed several empirical studies describing a case which can be considered the general one as well as demonstrated some exceptions to the prevailing relationship.
A novel aspect of my empirical work was the use of rather uncommon methodology, in particular, paying explicit attention to larval instars and recording both development time and final size for separate instars. Furthermore, the extensive literature review now enables us to make generalizations and conclusions about shapes of reaction norms in insects.