Johansson lab: Our research

Genetic variation and adaptation in novel environments

The aim is to understand (cryptic) genetic variation and adaptation at range margins. Cryptic genetic variation (the dark matter of biology), is variation that is normally not expressed, but is released when the organism encounters a novel environment. In stable environments, selection generally stabilizes towards an optimum that might not be optimal at novel environments. Nevertheless, most organisms are capable of quite fast adaptation to novel environments, and cryptic genetic variation is a potential explanation for this puzzling observation. Life history and morphological traits, and gene expression are studied in a damselfly system, and a mixture of field experiment, laboratory experiment and molecular methods are being used.

Urban ponds: species-genetic diversity correlations in a metacommunity

The main aim is to understand how the correlation between species diversity and genetic diversity in a network of city ponds is affected by environmental variables and community ecology affects. Traditionally species diversity and genetic diversity have been studied independently. This is unfortunate since the stability, resilience and dynamics of biological systems is linked to both genetic and species-based components. This study aims to fill this knowledge gap by studying species-genetic diversity correlations in an urban landscape. This is done by sampling and analysing properties of the aquatic community and environmental variables in city ponds of Stockholm.

Potential responses to climate change: from genotype to community level

In this research we try to understand how future climate change will affect species, population and communities. We do this by focusing on life history traits, species interactions and food web dynamics. Some of the question we are answering are: (1) How do thermal performance curves differ between species and latitudes? (2) How does animal behaviour change in a warming world and how does this affect e.g. cannibalism and predation rate? (3) How do community interactions affect the predicted life history response obtained from single species laboratory experiments?

Our research is funded by The Swedish Research Council and FORMAS (the Swedish Research Council for Sustainable Development).