We are interested in the processes that generate biodiversity. In our research, we investigate the processes that have made plants and plant-feeding insects two of the most diverse and abundant groups of organisms on earth.

We combine genomic, evolutionary and ecological studies to ask and answer questions about the distribution, diversification and conservation of biodiversity within and among species, and in particular how these patterns and processes are affected by the interaction between plants and insects. Our research bridges the gap between zoology and botany by integrating studies of animal- and plant biodiversity. We study spatial patterns in plant signalling and defence traits and insect host- /and nectar plant preference, and how these interactions are affected by the nature of the plant-insect relationship (antagonistic/mutualistic), by the specificity of the interaction, and by the geographic context at landscape- and continent scales. We are also interested in how within species variation enables and facilitates adaptation, knowledge that is crucial for management of insect populations that can adapt and survive in a changing climate.

We collaborate closely on most projects, which allows us to use our complementary expertise and perspectives to understand how ecological and evolutionary processes, including species interactions, can generate novel biodiversity. We co-supervise MSc and PhD-students and encourage postdoctoral researchers to work with several groups.

We encourage scholars interested in postdoctoral positions to approach and ask for the current possibilities to apply for joint funding.

Anna Runemark lab

I am a diversity and speciation researcher with evolutionary genomics and biogeography expertise and a background in evolutionary ecology. Broadly, my research strives to identify how variation arises and the processes by which it sorts into new species, as well as which ecological settings and factors that promote these processes.

Øystein Opedal lab

I am interested in understanding how plants and their interactors (pollinators, seed predators, herbivores) respond to changing environments. Currently, my main research activities include studies of mating-system and floral evolution in the neotropical vine Dalechampia, and studies of the role of species interactions in structuring the spatial and temporal dynamics of communities. I am also interested in understanding how alpine plant communities respond to climate change. I study these processes in the field, in the greenhouse, and through comparative (meta-)analyses.

Magne Friberg lab

In our lab group, we acknowledge that most species interactions evolve in site-specific networks of multiple coevolving species, and that each interaction is likely shaping suites of traits on both sides of the interaction. Therefore, our study systems often include multiple plant- and insect species that form small interaction networks. In these networks, we study plant and insect trait evolution, and the role of trait diversification for gene flow and local adaptation. Please read more about our research below.

Maja Tarka lab

In our lab group we study how natural and sexual selection shapes phenotypes in wild beetle and bird populations, why some populations are more evolvable than others and how the evolutionary potential constrain or facilitate adaptation to a changing environment.

Rachel Steward Lab

My work sits at the intersection of evolutionary genomics and ecology, with a primary focus on how organisms adapt to novel or changing environments. My current research explores the genomic architecture, transcriptomic mechanisms and multitrophic conditions that allow species to transition to new ecological niches and that mediate multiple host use by herbivorous insects (i.e., diet plasticity). I am also interested in the transcriptional basis of phenotypic plasticity. 

Yedra García lab

I am an evolutionary ecologist interested in how ecological interactions within multi-species communities shape the ecology and evolution of flowering plants. My research focuses on floral phenotypes, including scent, colour, and morphology, and how they respond to interacting biotic and abiotic selective pressures. By integrating evolutionary biology with community ecology across spatial and temporal scales, I aim to understand how multi-species interactions drive floral trait diversification and evolutionary change.

Sissi Lozada-Gobilard lab

My research group investigates how phenotypic variation and selective pressures shift across spatial and temporal environmental gradients—from tropical mountains to urban landscapes—and how these dynamics drive floral trait evolution. In particular, our current work in the tropical Andes of Bolivia examines how pollinator assemblages and climatic variation shape flower traits and patterns of natural selection along a pronounced altitudinal gradient (500–5000 m). By integrating ecological and evolutionary approaches, we analyse how selection imposed by pollinators varies over time and space, generating divergent evolutionary trajectories in contrasting environments. This research provides a rigorous empirical framework for understanding how environmental heterogeneity influences biodiversity and ecosystem dynamics in tropical systems.

Primary investigators

• Magne Friberg
• Yedra Garcia Garcia
• Sissi Lozada Gobilard
• Øystein Opedal
• Anna Runemark
• Rachel Steward
• Maja Tarka

Postdocs

• Danielle Clake
• Pedro Juarez
• Nick Planidin
• Andrés Romero Bravo
• Quijie Zhou

PhD-students

• Aurélien Caries
• Sophie Hecht
• Alex Lawrence
• Aarushi Susheel
• Erica Winslott

Research engineer

Petronella Wessman

Masters-/internship students

• Yinou Chen
• Xufei Cheng
• Tabea Dittmar
• Ege Güney
• Kajsa Karlsson
• Hanna Melzén Forss
• Sofia Moreno de la Cuesta
• Mattia Russo
• Marissa Tillman
• Madeleine Tindall

Alumni

• Zainab Awad Aliwi (MSc thesis defended in 2023)
• Sofie Alveteg (MSc defended in 2025, now ecologist at WSP)
• Cheng Bi (visiting PhD student, Lanzhou University China)
• Ana Botelho (MSc defended in 2025, now PhD student at Aarhus University)
• André Bourbonnais
• Sotiria Boutsi (moved on to PhD studies at Harper Adams University)
• Andrés Romero Bravo (moved on to PhD studies at University of Sussex)
• Shruti Choudhary (moved on to postdoc at Swedish University of Agriculture Sciences, Umeå)
• Katherine Eisen (moved on to professorship at Loyola Marymount University)
• Karin Gross (moved on to postdoc at Paris Lodron Universität Salzburg)
• Juan Isaac Moreira Hernandez (moved on to postdoc at Uppsala University)
• Laura Hildesheim (PhD defended in 2025)
• Yajuan Huang (moved on to PhD studies at Gothenburg University)
• Patrycja Jamelska (moved on to PhD studies at University of Neuchâtel)
• Samantha Skye Duhe Jones (MSc defended in 2024, now PhD student at Lund University)
• Svante Koldenius (BSc defended in 2025, now continues biology studies)
• Emma Kärrnäs (moved on to PhD studies at Lund University)
• Theadora Elizabeth Laorenza
• Sofia Torres Lara (moved on to PhD studies at Bremen University
• Anna Lundgren (now PhD-student at Uppsala University)
• Clara McNaughton Montgomery (MSc thesis defended in 2023)
• Kalle Nilsson (PhD-thesis defended in 2024)
• Zachary Nolen (PhD defended in 2025, now postdoc at Lund University)
• Jesus Ortega (moved on to postdoc at the Institute of Evolutionary Biology (CSIC-UPF), Barcelona)
• Homa Papoli Yazdi (moved on to postdoc at Lund University/University of Michigan)
• Karolina Pehrson (moved on to PhD studies at Linneaus University)
• Hampus Petrén (PhD-thesis defended in 2020, moved on to postdoc at University of Marburg)
• Cristina Rodríguez‐Otero (MSc thesis defended in 2021)
• Isolde van Riemsdijk (moved on to postdoc at Copenhagen University)
• Aarushi Susheel (MSc thesis defended in 2024)
• Kajsa Svensson (moved on to PhD studies at SLU Alnarp)
• Vanda Témesvari (MSc thesis defended in 2022)
• Hanna Thosteman (PhD defended in 2024, now postdoc at Swedish University of Agriculture Sciences, Alnarp)
• Erik Wendel (MSc thesis defended in 2024)
• Chao Yan (MSc thesis defended in 2021)

Below, we list some of the major research current projects in the research group. Please contact us for more information and opportunities.

Plant genome duplications and the evolution of plant-insect interactions

Diversification requires processes that generate diversity (mutation, recombination) and processes that filter this diversity (drift, natural selection). In plants, the most dramatic form of mutation is polyploidization, the duplication of the chromosome set. We investigate the direct effects of polyploidization on phenotypic traits of importance for plant-insect interactions (e.g. floral scent and morphology), using different ploidy-types of the plant Lithophragma bolanderi as model. This species involves multiple ploidy-levels, and different populations are highly variable in floral scent and morphology, and in the propensity to form asexual propagation bodies (root bulbils). Ecology may interact with genomic architecture if pre-existing selection for asexuality facilitates establishment of polyploid lineages; e.g., in conditions where pollination is unreliable, selection should favour asexual reproduction also in diploid populations. Thus, the success of novel polyploids may depend on plant-insect interactions. We combine genomic methods with greenhouse experiments and ecological field studies to address how ecological processes and genomic architecture interact to shape resource allocation into sexual and asexual reproduction, and how this variation facilitates the origination of ploidy-level variation.
Contact: Magne Friberg or Anna Runemark

The ecology and evolution of plant mating systems

Plants exhibit remarkably diverse sexual systems that range from obligate selfing to enforced outcrossing through self-incompatibility, separate sexes, or spatial or temporal separation of sex function within bisexual flowers. Among self-compatible species, most exhibit mixed mating systems, in which a proportion s of offspring are produced through self-fertilization, and a proportion t = 1 – s through outcrossing. We use the tropical vine Dalechampia and the Eurasian herb Arabis alpina as model systems to assess which ecological factors (e.g. pollination reliability, intensity of seed predation) that drive the evolution of mating systems among populations.
The same advertisements that attract pollinators can be picked up also by herbivores and seed predators. Local variation in these networks is likely to be an important driver of geographical variation in plant signaling. In A. alpina several populations have evolved self-compatibility. These populations also vary substantially in floral morphology and chemical floral signaling, and provide an interesting model system for understanding the relationship between different floral signals, the plant mating system and the local community of associated insects.
Contact:  Øystein Opedal or Magne Friberg

How does adaptation to a novel niche mould genomes and phenotypes?

Using host-plant-specific subspecies of the fly T. conura we investigate the adaptations following host-plant shifts and identify the areas in the genome associated with these phenotypic characters. We are particularly interested in how coding genetic divergence and regulation of gene expression interact during adaptation. Broadly, this research strives to increase the understanding of how ecological selection can lead to divergent adaptation and creation of novel diversity. A new niche implies altered selection pressures on several aspects of the phenotype, and this will generate correlational selection for certain combinations of traits/loci. Ultimately, we also aim to address how non-physical linkage disequilibrium arises when several genomically unlinked loci are selected to be coinherited, and how this process affects both genetic variation and evolvability.
Adaptation to new environments and selection pressures can be either plastic or genetic. We investigate whether the relative contribution of these different mechanisms differs between populations that are facultatively using two different host plants and would be predicted to benefit from plastic responses, and these that are host plant specialists. We address this through combining data on differences in gene expression with data on the fitness consequences of generalist behavior and specialization within the same species. The genetic basis of adaptation is highly relevant for the ability to adapt, and speed at which species and populations may adapt, to a changing climate. This research is supported by a Swedish Research Council Establishment Grant.
Contact: Anna Runemark

Understanding pollinator-mediated reproductive interactions

Whenever plant species that share pollinators flower together, there is scope for plant-plant interactions mediated by pollinators. These reproductive interactions can have direct fitness consequences for each plant species, and may affect the assembly of communities. The coflowering community may also affect patterns of natural selection on each species, and thus drive evolution of flowers and whole-plant phenotypes. We are currently looking for students, PhD candidates and postdocs interested in working on these issues!
Contact: Øystein Opedal

Coevolutionary divergence in tight mutualisms

Obligate relationships between prodoxid moths and their host plants are among the best-studied examples of coevolution in nature. The moth Greya politella simultaneously pollinates and lays eggs into the flowers of its Lithophragma host plants (Saxifragaceae). We study the evolution of floral scent variation, and its importance for interaction specificity and population and species divergence among both the plants and the insects. Further, we compare the impact of selection from the specific moth pollinators with the evolutionary effects of generalized co-pollinators at various geographic scales.
Contact: Magne Friberg

How can hybridization create novel variation?

Hybridization is increasingly recognized as an important evolutionary force, creating novel variation. To understand how novel combinations of parental alleles can form new fit phenotypes we use a unique study system, consisting of independently formed hybrid populations of Italian sparrows on Mediterranean islands for which we have sequenced entire genomes. We are interested in whether specific combinations of genotypes repeatedly arise, and which regions of the genome are free to vary. We also work on how evolution of regulation of gene expression in a hybrid species can contribute novel variation, and investigate whether Transposable Elements are re-activated in hybrid genomes in collaboration with Dr. Alexander Suh.
Contact: Anna Runemark

The Dynamics of Complex Terrains

The environments inhabited by natural populations are not homogeneous, but vary at scales ranging from continents to centimetres. Alpine landscapes, for example, are often very heterogeneous due to the complex topography characteristic of mountain landscapes. Environmental heterogeneity associated with topographic complexity have myriad consequences for the organisms inhabiting these environments, not least their ability to persist when the environment is changing. Populations can respond to environmental change in two basic ways: either stay where you are and adjust or adapt to novel environmental conditions, or migrate to track favourable environments elsewhere. Populations that fail to do so are likely to go extinct due to competition from well-adapted invaders. We have been interested in how topographically complex landscapes differ from more homogeneous ones. One consistent pattern is that complex landscapes tend to contain more species, most likely due to the greater range of microenvironments available on complex landscapes. Furthermore, complex landscapes tend to be more variable in space, so that when walking across the landscape, you will tend to encounter more different species. In ecological terms, complex landscapes are characterized by greater beta-diversity. Why does this matter for populations experiencing environmental change? The first reason is that migrating to a new spot that is, say, 2 degrees cooler on average is easier if that spot is 10 meters away than if it is 1 kilometre away, at 300 meters higher altitude. Thus, complex landscapes may allow persistence of local populations through reshuffling of species on the landscape. A second reason is that populations occupying complex landscapes may differ genetically from those occupying more homogeneous ones. For example, environmental heterogeneity is thought to select for phenotypic plasticity; the ability of a genotype to produce different phenotypes depending on environmental conditions. Furthermore, environmental heterogeneity could select for greater genetic diversity and thus greater abilities to respond to further environmental change.
Contact: Øystein Opedal

Evolutionary perspectives on conservation

In a changing climate, rapid adaptation to cope with e.g. extreme weather may be crucial for survival. The importance of the ability to adapt is illustrated by the world-wide insect population declines, which occur both inside and outside protected areas. Genetic variation provides material for adaptation and is hence necessary for rapid evolutionary response. Maintaining genetic variation is thus pivotal for long-term preservation of biodiversity. We use advanced genomic analyses to address how spatial planning to maintain genetic variation that enables evolutionary adaptation and long-term persistence should be designed. Specifically, we study focal species of the blues (Polyommatini) to address how fragmentation of grazed semi-natural grasslands affects genetic diversity and evolvability. We investigate how reductions in genetic variation compared to historical levels depend on habitat fragmentation, species and historical levels of genetic variation. We also aim to address what landscape properties and species characteristics affect gene flow. Financed by Oscar & Lili Lamms Minne.
Contact: Anna Runemark

Diversification of butterfly traits across space and time.

We study spatial and temporal variation in several insect traits, with implication for diversification and conservation. We have a long-term focus on the evolutionary ecology of butterflies, and, in a long-term project, we have aimed our studies at understanding the evolution of host preference variation of Pieris butterflies, which are utilizing multiple plants of the Brassicaceae family. Traditionally, studies of host plant related diversification and specialization of phytophagous insects have been focusing on the evolution of the larval ability to digest and develop on different host plant species. Surprisingly, fewer studies have investigated the evolution of host plant preferences as a driver of host specialization, even though the female host plant choice represent the first step of the filtering process in the insect host choice, since females of most species decide on which host individuals her offspring will be feeding.
Recently, in collaboration with Erik Svensson, we have initiated studies on the evolution of female color polymorphism in the common blue butterfly (Polyommatus icarus), and, in collaboration with Richard Walters (CEC), we recently received a grant from the FORMAS research council to increase the precision of models of butterfly movement in disturbed landscapes.
Contact: Magne Friberg

Genomic and transcriptomic architecture of host use

Ecological divergence can occur over remarkably rapid timescales and the specific genomic and transcriptomic architectures underlying this process are unclear It is becoming clear that structural variants (SVs), such as inversions, exert a profound influence on evolutionary trajectories. Repetitive content, specifically transposable elements (TEs), also represent a previously underappreciated yet pervasive axis of genomic variation. Crucially, both SVs and TEs can drive transcriptional variation, potentially giving rise to novel or divergent phenotypes. However, the precise mechanisms by which this genomic architecture alters gene expression and alternative splicing during adaptive divergence remain poorly understood. Using peacock flies (Tephritidae) as a model system, we investigate the roles of SVs and TEs in niche breadth, adaptive divergence, and speciation. Our research aims to identify the transcriptomic mechanisms through which SVs and TEs generate phenotypic plasticity or divergence and quantify how these genomic features ultimately influence organismal fitness. 
Contact: Rachel Steward

Multitrophic multi-omics of diet plasticity

Niche colonization and specialization is a dynamic process shaped by continuous interspecific interactions, complicating our understanding of how populations diverge. Host-associated differentiation (HAD) – when insects colonize a new host plant leading to genomic divergence – depends not only on the insect traits, but also interactions across multiple trophic levels, including the host plant's chemical and nutritional landscape and its associated microbial communities. Without a mechanistic understanding of the interaction between plant, insect, and microbes, it is impossible to determine the ecological pressures that promote host-associated differentiation, ultimately impacting patterns of biodiversity.  Historically, linking the multitrophic components that mediate host-associated differentiation has been challenging. Modern analyses now allow for the integration of diverse -omic datasets. For organisms with tightly linked life histories, such as specialized insects and their hosts, this provides a transformative opportunity to bridge data not just within an individual, but across entire trophic levels. Using the Peacock fly (Tephritis conura) as a model for ongoing ecological speciation, we employ a multi-omic framework to investigate 1) plant metabolomics: the chemical landscape of different hosts; 2) microbial associations: the symbiotic communities that facilitate or hinder host use; 3) insect gene expression: transcriptomic responses to novel host and microbial environments.
Contact: Rachel Steward

Floral evolution in a community context

In flowering communities, plants usually experience selection from pollinators, antagonists, neighbouring plant species, and environmental conditions, which may interact to generate context-dependent selection. Our research explores how floral phenotypes evolve within multi-species communities by taking an integrative perspective on floral traits and ecological drivers. We investigate how floral scent, morphology, and colour are shaped by interacting biotic and abiotic selective pressures, with particular emphasis on interactions among pollinator-sharing co-flowering species. Using orchid communities on the Baltic island of Öland as a study system, we adopt a multivariate, community-level approach to understand how these combined factors shape patterns of selection and drive floral diversity over time.
Contact: Yedra García

Ecological and evolutionary drivers of floral polymorphism

We investigate the ecological and evolutionary mechanisms underlying floral polymorphism using the food-deceptive orchid Dactylorhiza sambucina as a model system. This species exhibits striking colour morphs that coexist within natural populations and are thought to be maintained through negative frequency-dependent selection. However, whether variation in other traits, such as floral scent, parallels colour polymorphism remains poorly understood. We examine how plant–pollinator interactions, interactions with co-flowering species that share pollinators, spatial variation in biotic factors, and abiotic heterogeneity contribute to the persistence of this polymorphism in natural populations. By integrating selection studies in the field and multivariate latent-variable analyses with genomic approaches, we aim to uncover the ecological and genetic basis of trait variation among morphs and test for evolutionary processes, such as balancing selection, that maintain phenotypic diversity within populations, particularly in the context of co-flowering communities.
Contact: Yedra García

Floral Modularity, Mating Systems, and Pollination Systems

We investigate how flower trait integration and modularity influence evolutionary flexibility in response to environmental pressures. We hypothesize that high trait integration corresponds with pollination specialization and outcrossing, while more modular systems are associated with generalization and reproductive assurance (e.g., selfing). To test this, we are building a database of different species occurring along the altitudinal gradient to relate flower traits, biotic factors (pollinators), abiotic factors (climate) and reproductive fitness. Preliminary results from 2023 and 2024 show that more generalized species have lower trait integration and higher variance in fit traits.
Contact: Sissi Lozada-Gobilard

Selection and Adaptation to novel pollination environments

Using native European and introduced South American populations of Digitalis purpurea, we investigate how plants respond evolutionarily to novel pollination environments. In its native range, the species is primarily bumblebee-pollinated, whereas in South America it interacts with new pollinators, including hummingbirds. We quantify variation in floral colour, morphology, nectar traits, and reproductive success to estimate pollinator-mediated selection across contrasting environments. By comparing native and introduced populations, we test whether divergence in floral traits reflects rapid adaptation, phenotypic plasticity, or shifts in selective regimes, providing a tractable system to study evolutionary responses to ecological novelty.
Contact: Sissi Lozada-Gobilard

Community Ecology in Urban Systems

In urban and transitional habitats of La Paz city, we examine how floral phenotypes, pollinator assemblages, and patterns of selection interact in human-dominated systems. Focusing on species such as Nicotiana glauca and Lupinus altimontanus, we quantify trait variation, visitation dynamics, and fitness components (seed set and reproductive success) to estimate contemporary selection on floral traits. In Lupinus, we additionally use genetic markers to characterize contemporary pollen flow, allowing us to disentangle male and female components of selection and to assess how urban environments influence mating patterns and gene dispersal. Together, this work clarifies how ecological context shapes both phenotypic selection and reproductive dynamics in rapidly changing landscapes.
Contact: Sissi Lozada-Gobilard