Dept. of Ecology and Evolution/Animal Ecology
SE-752 36 Uppsala
+46 (0)18 471 2639
+46 (0)18 471 6484
My general interests lie in the fields of Evolutionary Biology and Behavioural Ecology. I mainly use fishes as model organisms to investigate the causes and consequences of the enormous diversity in morphology, life-histories and behaviour that we find among animals at the levels of individuals, populations and species. The tools I use range from field observations to controlled lab experiments and comparative analyses.
Currently I focus on three main areas of research:
1. Sensory exploitation and the evolution of animal signal/receiver systems
In this project, I investigate the evolution of Sensory Exploitation and its implications as a starting point for the evolution of signal-receiver interactions in a mate choice context. This work is based on field studies and lab experiments on a remarkable species of fish, Corynopoma riisei, a Trinidadian Characid. In this species, the male carries a paddle-like structure growing from the operculum on each side of the body. At the end of each paddle there is a flag-like appendix. During courtship, males wave these paddles in front of a female who (believing it is a food item) bites at the flag-like structure and thus positions herself so that the male can insert a sperm package into the female with lighting speed. The female can then store this sperm package for an extended period of several months and use it to fertilise several batches of eggs. Moreover, the male has three different pairs of pheromone glands (one near the tail, one on the gills and one near the pelvic fin) that he evidently uses during courtship. Using this species, I investigate, in collaboration with Mirjam Amcoff, PhD-student in my lab, and Göran Arnqvist, the following questions:
-What are the fitness consequences for females from responding to sensory exploitation?
-Can sexual selection through sensory exploitation lead to populations diverging and hence speciation?
-What scenarios drive the evolution of multiple sexually selected traits in males?
-What are the causes and consequences of laterality in male sexual signalling?
-What are the costs of carrying extreme sexual signals?
-What are the effects of male courtship pheromones on females?
Male C. riisei
The C. riisei lab at EBC
Field collection of C. riisei with Göran Arnqvist
2. Evolution of parental care patterns, sexual dimorphism, life histories, body size and brain structure in cichlid fishes
In all these traits, the cichlid fishes display an enormous variation. I use formal comparative analyses to investigate (within the correlative frame-work of such analyses) the adaptive reasons for this variation and also the links between the various aspects of the ecology of these species. Together with Alejandro Gonzalez Voyer, Wenner-Gren Foundations funded post-doc in my lab, and collaborator Svante Winberg, I focus mainly on the following questions:
-What are the causes of variation in parental care patterns in cichlid fishes?
-What factors have driven the link between sexual selection and parental care patterns in this group of fishes?
-What are the evolutionary patterns of brain size and brain structure in the Tanganyikan group of cichlids?
-What are the causes of variation in brain size and brain structure among the sexes and species in this group?
-Is there any link between brain structure and speciation patterns in Tanganyikan cichlids?
-Are there trade-offs between the different regions of the vertebrate brain?
-What are the causes of sexual size dimorphism in this group? And what are the relationships between different aspects of sexual selection (e.g. sexual size dimorphism, sexual dichromatism, mating system, sexual morphological dimorphism) in this group?
3. Variation in brain structure among individuals with different life-history strategies within a wild population of brown trout
Almost nothing is known about the intra-specific variation in brain structure among vertebrates. For this project I investigate, in collaboration with Svante Winberg, Daniel Brelin and Claes Dellefors, differences in brain structure among different mating strategies of brown trout from river Jörlanda in Gothenburg.
Hard at work, actively standing next to a bucket, at river Jörlanda. Claes Dellefors, Sweden's most skilled electrofisher, is exercising his craft in the background
Previous (but far from buried!) interests
During my PhD (supervised by Anders Berglund and Ben Sheldon) I investigated mutual mate choice, size assortative mating, differential allocation, group stability, information contents in female courtship behaviours, population biology and conservation biology using the Banggai cardinalfish as a model. These studies enabled me to start up collaborations with for instance Eric Hoffman and Jens Olsson. Given the extreme ease with which one can perform controlled field experiments on this species (the species form highly stable group structures at only 2 metres depth), I aim to continue some of these investigations in the future.
Female Banggai cardinalfish (lower specimen) courting a male
Field observations of the Banggai cardinalfish in the field at Sulawesi, Indonesia
During my post-docs at UEA and Edinburgh University I started getting interested in investigating life-history evolution using comparative methods. Together with Nick Goodwin and John Reynolds I got into comparative analyses on the cichlid system at UEA. This was later followed by a comparative study on Galliform birds in collaboration with Emma Cunningham, Will Stein and Arne Mooers while in Edinburgh. Brent Emerson at UEA also got me interested in large-scale analyses of what factors causes diversification, a collaboration that continues today.