The management of populations in the face of environmental change, both natural and man-made, is challenging. Our research examines diverse species, from yeast to wolves, each of which is facing different challenges. We use a range of tools, from sampling wild populations to experimental evolution in the lab, whole genome sequencing, computer simulations and theoretical modeling. We participate in multidisciplinary research efforts and outreach activities aimed at bridging the current gap between scientific knowledge on genetic diversity and the use of this knowledge in practical management.


The Lakes Bävervattnen Project

Hotagen Nature Reserve and Natura 2000 area is located in the County of Jämtland, Sweden. Here, brown trout and Arctic char populations of three water systems are monitored genetically over time since the 1970s. These empirical data feed into many of our projects and are, and have been, used for a variety of fundamental issues relating to population dynamics and conservation genetics of both natural and experimentally released populations. Presently, the long term data series generated within this study provides important basis for the following projects of our group: Genetic monitoring and goals for conservation, Effective population size of metapopulations, and Genetic diversity in environmental monitoring.

Principal Investigators: Linda Laikre, Nils Ryman
Contributing Researchers: Anastasia Andersson, Sara Kurland


Effective population size of metapopulations

The genetically effective population size (Ne) is the most widely used parameter for quantifying and monitoring rates of inbreeding and loss of genetic variation through drift. The concept was developed for single, isolated populations; Ne is defined as the size of an ideal population without the evolutionary forces of mutation, selection or migration that exhibits the same expected rate of genetic drift or inbreeding per generation as the actual, real life population of interest. We develop methods for modelling and understanding the dynamics of Ne in substructured populations (metapopulations), apply these to empirical cases and formulate conservation recommendations. We also address questions associated with estimating Ne from empirical data.  

Principal Investigators: Linda Laikre, Nils Ryman
Contributing Researchers: Sara Kurland
Collaborators: Ola Hössjer


Genetics and life history dynamics of cryptic, sympatric salmonid populations

Genetically distinct, sympatric populations have been reported in several salmonid species and they are typically detected based on morphological or behavioural differences. In a few, rare cases sympatric populations have also been detected without obvious phenotypical differences, based on genetic data alone (i.e., cryptic populations). We work to understand the evolutionary mechanisms behind such sympatric populations including whether life history divergence occurs or whether, in fact, cryptic sympatric populations can exist in the absence of such divergence. We also address statistical power issues related to the detection of sympatric populations.

Principal Investigators: Linda Laikre, Nils Ryman
Contributing Researchers: Anastasia Andersson
Collaborators: Per Erik Jorde


Genetic monitoring and goals for conservation

We study microevolutionary processes relating to conservation issues using empirical genetic data from a wide range of species. We describe patterns of genetic biodiversity over space and time, work to understand the processes that shape these patterns, and recommend how the information can be used for sustainable management and conservation genetic guidelines.  

Principal Investigators: Linda Laikre, Nils Ryman
Contributing Researchers: Anastasia Andersson, Sara Kurland, Maria Celorio, Lovisa Wennerström, Mari Edman



Experimental Evolution with Yeast 

We study hybridization between divergent evolutionary lineages and the effect that the exchange of genetic material has on adaptation, reproductive isolation and speciation. For this, we use experimental evolution with Saccharomyces (Baker’s) yeast and the newest genome and RNA sequencing tools, which allow us to observe evolution in the lab over hundreds of generations within a few weeks time.

Principal Investigator: Rike Stelkens
Contributing Researchers: Ahmed Arslan, Ciaran Gilchrist


Adaptation to Environmental Stress 

We live in a world where the pace of environmental change poses serious threats to biodiversity. To avoid extinction when environments deteriorate, species must evolve to adapt to the new or extreme conditions. Here, we use the microbial model system Saccharomyces yeast to understand the genomic and transcriptomic basis of adaptation, such as which and how many loci are involved in adaptation to environmental stress, and how these loci interact. Yeast genomes are easily manipulated and well suited to investigate the causality of specific mutations in adaptation.

Principal Investigator: Rike Stelkens
Contributing Researchers: Ahmed Arslan, Ciaran Gilchrist


Bridging the conservation genetics gap

The goal to protect biodiversity is clearly stipulated in international agreements such as the United Nations Sustainable Development Goals for 2030 ( and the Convention of Biodiversity ( The ambitions are clearly stated - to maintain biological variation at the levels of genes, species and ecosystems – but implementation is difficult. This is particularly true for the genetic level of biodiversity. Our research, followed by many others, has shown that implementing conservation policy for genetic diversity lags considerably behind work for other biodiversity levels. This is in spite of genetic diversity contributing to the basis of all biodiversity by providing the tools for adaptation to environmental change and, thus, long term survival. Further, decades of conservation genetic research has contributed with a wealth of information of relevance for management, although it has been poorly used. This phenomenon is referred to as the “conservation genetics gap”. We work in multi-disciplinary teams to investigate if and how genetic knowledge is used in management, why the conservation genetic gap exists and what means are effective to bridge it.

Principal Investigators: Linda Laikre
Contributing Researchers: Anastasia Andersson, Lovisa Wennerström, Mari Edman
Collaborators: Annica Sandström, Carina Lundmark, Klas Andersson, Andreas Duit, Sanna Lundquist


Genetic diversity in environmental monitoring

Genetic diversity is the basis of all biodiversity and is essential for populations´ and species´ long term survival and adaptation. This is recognized in international conservation policy but poorly implemented in practice. In Swedish environmental monitoring genetic diversity is presently not considered at all. This is a pilot project to suggest how genetic diversity can be included in monitoring programs. Two model species are used representing marine and freshwater habitats – Fucus and brown trout (Salmo trutta) – where our group focuses on the trout whereas the Fucus pilot is run by Professor Kerstin Johannesson at University of Gothenburg.

The brown trout has an ecological key role in many freshwater habitats particularly in mountainous areas where it is often the only or one of only few fish species. These areas are subject to climate changes, and intraspecific diversity of brown trout is also potentially affected by stocking and fishing activities. A unique asset for genetic monitoring is available for brown trout at Stockholm University; a frozen tissue archive covering four decades of sampling; comprising over 40,000 individual tissue samples from more than 200 water sites. This material provides a basis for the pilot study; geographic areas including interlinked water systems reflecting metapopulations of brown trout are selected in collaboration with regional managers and revisited. Potential changes over 30-40 year time spans are investigated using modern genetic techniques and will aid in forming a strategy conservation genetic monitoring.

Principal Investigators: Linda Laikre, Nils Ryman
Contributing Researchers: Anastasia Andersson, Mari Edman, Jerry Andersson
Collaborators: Kerstin Johannesson


Genetic structure and migration patterns of Baltic Sea pike

The pike (Esox lucius) is an important predator in Swedish coastal waters where it is also a popular target for sport fishing. The pike is of conservation concern, because some coastal populations have declined or almost desappeared. Together with the Stockholm County Administrative Board and the project ReFisk we are mapping spawning sites of pike on the east coast of Sweden. Using genomic tools we are estimating migration rates between, and effective population size and genetic diversity within spawning sites. These genetic analyses will be complemented by abundance estimates and food web analyses. The aim is to evaluate and improve current management practices.

Principal Investigators: Linda Laikre
Contributing Researchers: Lovisa Wennerström

Baltic Sea Marine Biodiversity – BONUS BAMBI

Our overall goal is to assess and improve capacities of marine species to deal with the current challenge of a rapidly changing Baltic Sea environment. To reach this goal we need to understand the potential of organisms to evolve new adaptations and how management should be framed to support this. Please visit the project website:

Principal Investigators: Linda Laikre
Contributing Researchers: Lovisa Wennerström, Mari EdmanSara Kurland

Other members of the team: