Department of Ecology and Genetics

The evolutionary ecology of life histories

Life history theory is fundamental to our understanding of organisms in nature. We study how organisms allocate resources to growth, reproduction and maintenance throughout their lives. In studying this problem we focus on how both genes and the environment affect life history traits and their evolution, and in particular questions like:

At what age and size should individuals start to reproduce? Should they reproduce more than once, and if so, at what intervals? How many resources should be allocated to reproduction as opposed to self-maintenance? Should individuals invest more in trying to attract a mate of outstanding quality, or in securing a high quality environment in which to raise their young? What determines ageing? What is the role of metabolism for life history evolution? What role does mitochondrial genetic variation play in life history evolution?

We study these questions in flycatchers (see Lars Gustafsson and Anna Qvarnström), fish (see Richard Svanbäck), amphibians (see Frank Johansson and Anssi Laurila), insects (see Göran ArnqvistDavid Berger, Frank Johansson and Alexei Maklakov), snails (see Anssi Laurila) and nematodes (see Alexei Maklakov and Martin Lind).

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The ecology of behaviour

Traits that make their bearers more successful than others in competition over mates will be favoured by sexual selection. Adaptations for expanding or restricting the set of potential mates will evolve if there is genetic variation for such traits. So called "secondary sexual" characters are adaptations for successful competition for access to mates, while mating preferences are adaptations for excluding individuals of insufficient quality as potential partners. We study the evolution of these adaptations and the sexual conflict underpinning them. The role of sexual selection for "primary" sexual characters is another topic of interest. We also study the evolution of signals and cognition to understand mechanisms behind these adaptations.

Sexual selection, sexual conflict, signals and cognition are studied in birds (see Mats Björklund, Jacob Höglund, Lars Gustafsson, Anna Qvarnström and Anders Ödeen), fish (see Ingrid Ahnesjö, and Anders Berglund) and insects (see Göran Arnqvist and Alexei Maklakov).

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The ecology of speciation

The question of speciation has attracted a large number of researchers over the years, all with their own perspectives and approaches. In the Department of animal ecology we take a purely ecological view. Our main starting point is the question: what makes individuals in population A stop seeing individuals from population B as potential partners? The main theories of speciation by Mayr, Wright and others stress the importance of small, isolated populations as the main precursor of speciation and evolution of new adaptations. This forms the theoretical basis of our research - if a small population really is the main precursor for the evolution of mating discrimination, then it is of importance to understand the relative impact of the different ecological factors that lead to a small population size.

We study these questions in primates (see Katerina Guschanski), birds (see Mats Björklund, Lars Gustafsson and Anna Qvarnström), amphibians (see Anssi Laurila and Anna Qvarnström), snails (see Anssi Laurila) and insects (see Göran Arnqvist and Alexei Maklakov).

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Conservation biology

In conservation biology the focus is on the proper function of populations is upset. Insufficient population growth and impoverished genetic variation are two main causes. To address these questions we study, among other things, local adaptation in life-history traits, and the genetic structure of fragmented populations. All these studies contain conservation aspects incorporating responses to human-caused environmental disturbances. We are studying these aspects through field and laboratory experiments, through mapping of the genetic variation in extant and historical populations, through long-term studies of individual success in natural populations and through theoretical modeling.

We study these questions on whales (see Cecilia Anderung), primates (see Katerina Guschanski), birds (see Mats Björklund, Henri Engström, Lars Gustafsson, Jacob Höglund and Anders Ödeen), amphibians (see Jacob Höglund, Frank Johansson and Anssi Laurila), fish (see Anders Berglund, Mats Björklund, Frank Johansson and Fredrik Sundström), and snails (see Anssi Laurila).

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Theoretical evolutionary ecology

Biological systems are inherently complex and the resulting dynamical patterns are regularly rather unexpected and difficult to foresee by purely verbal reasoning. Mathematics is therefore an important tool to achieve an understanding of these complexities. We use mathematical models to investigate the dynamics of populations and evolutionary processes. More specifically, we use modeling to elucidate the evolution and maintenance of genetic and phenotypic diversity within and among populations. We are particularly interested in the role of constraints (e.g., sexual conflict) and ecological interactions in driving the evolution of such diversity.

People working in this field: Claus Rueffler, Göran Arnqvist, Mats Björklund and Richard Svanbäck.