Group Karl Gotthard

My research is mainly been concerned with life history evolution and the evolution of phenotypic plasticity, using different species of butterflies as model systems. I have also worked on the evolution of host plant use in Chrysomelid beetles. Currently I am concentrating on the evolution of body size, developmetal plasticity and thermal reaction norms in insects but I am also continuing my research on the evolution of growth strategies and host plant use. You may find a more exstensive description of my past and present research under the research link.

From 2002 to 2006 I held a position as assistant Professor (Forskarassistent) at the Department of Zoology, Stockholm University, that was financed by the Swedish Research Council (Vetenskapsrådet). The titel of this project was "The evolution of body size in holometabolous insects" and it was based on one fundamental question: why don't insects become bigger? I am presently continuing this work with the aid of a grant from FORMAS (Life history theory and the evolution of body size in Butterflies). In 2008 David Bergner finished his Ph.D working within this project. He is now on a Post-doc with Wolf Blanckenhorn at the University of Zürich for which he recieved funding from the Swedish Research Council.

The problem of optimal age and size at maturity is based on the fundamental trade-off between the benefits of a large size and the costs of a long juvenile period. It is typically expected that organisms should be selected to maximize juvenile growth rate in order to reach the largest possible size in the shortest possible time. However, studies of a wide range of animals have shown that individuals facing a long growth season or very good food conditions often"voluntarily" reduce juvenile growth effort/rate rather than reach a greater final size at maturity. In herbivorous insects such "good condition"- larvae could theroretically end up twice or three times as large as they typically are, if they would maximize their growth rates for the whole larval period. So why don't they?

At present there is some evidence for costs of becoming big (e.g. mortality costs due to a long juvenile period or fast growth) but theory suggests that there are also costs of being big, which would challage the common assumption of an ever increasing relationship between size and fitness. The major goal of this project is to improve the knowledge of the evolution of body size in insects by focusing on the potential cost of being large. As a part of this research I also continue my work on the evolution of growth strategies.

We are presently using Pararginii-butterflies as model organisms but some of the work is also conducted on other species of Satyrines, including some threatened species (Lopinga achine and Coenonympha hero). We work in large outdoor cages the field, as well as with laboratory assays where we will try to estimate the relationship between adult size and fitness.

In 2008 I started a new project entitled "Evolution of developmetal plasticity in insects" (financed by the Swedish reserach council, VR). Developmental plasticity that leads to alternative phenotypes depending on environment is often controlled by developmental switches/thresholds. Such switches integrate environmental and genetic effects on phenotypes and are important mechanisms for the evolution of adaptive plasticity. This project will explore the evolution of developmental plasticity by mechanistic and genetic studies of developmental switches, as well as studies of how the expressed phenotypic variation influences fitness in realistic ecological settings. The project focuses on larval development in butterflies of the genus Pararge and deals with developmental switches of two different types (life cycle and color dimorphisms) that are sensitive to different environmental cues. Many insects have alternative developmental pathways (i.e. diapause or direct development) and one question that will be investigated is to what degree selection within one developmental pathway lead to correlated changes also in the alternative developmental pathway. Presently I have one Ph.D. student - Ingrid Haugen, working on this project.