Mattias Siljestam

Uppsala University | UU · Department of Ecology and Genetics, Animal Ecology

Moving animal groups, such as flocks of birds or schools of fish, exhibit a varity of self-organized complex dynamical behaviors and shapes. This kind of flocking behavior has been studied using self-propelled particle models, in which the “particles” interact with their nearest neighbors through repulsion, attraction and alignment responses. In pa...

While both innate and adaptive immune system mechanisms have been implicated in resistance against the chytrid fungus Batrachochytrium dendrobatidis (Bd), studies on the role of specific MHC haplotypes on Bd infection are rare. Here, we studied variation in MHC Class IIB loci in the common toad Bufo bufo along a latitudinal gradient across Sweden....

Populations of the same species may differ in their sensitivity to pathogens but the factors behind this variation are poorly understood. Moreover, infections may cause sub-lethal fitness effects even in species resistant or tolerant to disease. The chytrid fungus Batrachochytrium dendrobatidis (Bd), is a generalist pathogen which has caused amphib...

Anisogamy has evolved in a large proportion of sexually reproducing multicellular organisms allowing the definition of the female and male sexes, producing large and small gametes, respectively. Anisogamy is the initial sexual dimorphism: it has lead the sexes to experience selection differently, which makes it a good starting point to understand t...

Many organisms studied by evolutionary biologists have different sexes, and the evolution of separate sexes and sexual dimorphisms in morphology and behaviour are central questions in evolutionary biology. Considering scientists to be embedded in a social and cultural context, we are also subjected to the risk of gender-biased assumptions and stere...

While both innate and adaptive immune system mechanisms have been implicated in resistance against the chytrid fungus Batrachochytrium dendrobatitis, studies on the role of specific MHC haplotypes on Bd infection are rare. Here, we studied latitudinal variation in MHC Class IIB loci along a latitudinal gradient from southern to northern Sweden in c...

With a mathematical model we show that close to 20 coexisting alleles can evolve under sex-specific dominance. We also show that sex-specific dominance emerges when allowed to evolved. We conclude that sexually antagonistic selection under sex-specific dominance has the potential to explain high degrees of allelic polymorphism.

Many loci harbour allelic polymorphism, but the majority of highly polymorphic genes are related to the immune function. Genes of the major histocompatibility complex (MHC) are the most polymorphic loci in vertebrates with over 100 alleles reported within a population. How such extraordinary polymorphism arose and is maintained is controversial but...

Adaptive phenotypic plasticity is an important source of intraspecific variation, and for many plastic traits the costs or factors limiting plasticity seem cryptic. However, there are several different factors that may constrain the evolution of plasticity, but few models have considered costs and limiting factors simultaneously. Here we use a simu...