Richard Svanbäck

• PhD
• Professor (Associate) at Uppsala University

Resumo A especialização individual (EI) refere‐se à variação intrapopulacional no uso de recursos não relacionada à ontogenia, ao dimorfismo sexual ou à existência de morfotipos definidos. Um nicho amplo aumenta a especialização individual porque os indivíduos podem se segregar no espaço do nicho. Se a posição trófica influenciar a amplitude do nic...

Individual specialization (IS) refers to intrapopulation variation in resource use unrelated to ontogeny, sexual dimorphism, or discrete morphological variation. A broad niche increases individual specialization because individuals might segregate in niche space. If trophic position influences niche breadth, it would indirectly constrain the degree...

Background Microplastics are a pervasive pollutant widespread in the sea and freshwater from anthropogenic sources, and together with the presence of pesticides, they can have physical and chemical effects on aquatic organisms and on their microbiota. Few studies have explored the combined effects of microplastics and pesticides on the host–microbi...

Microplastics are persistent and complex contaminants that have recently been found in freshwater systems, raising concerns about their presence in aquatic organisms. Plastics tend to be seen as an inert material; however, it is not well known if exposure to plastics for a prolonged time, in combination with organic chemicals, causes organism morta...

Contamination by microplastics (particles < 1 mm) is a growing and alarming environmental problem in freshwater systems. Evidence suggests that industrial effluents could be one of the critical point sources of microplastics and other pollutants, and their interaction can cause organismal stress and affect host and environmental microbial communiti...

There is growing evidence of widespread contamination of freshwater ecosystems with microplastics. However, the effects of chronic microplastic ingestion and its interaction with other pollutants and stress factors on the life-history traits and the host-microbiome of aquatic invertebrates are not well understood. This study investigates the effect...

Background Microplastics are a pervasive pollutant widespread in sea- and freshwater from anthropogenic sources, and together with the presence of pesticides, they can have physical and chemical effects on aquatic organisms and on their microbiota. Few studies have explored the combined effects of microplastics and pesticides on the host microbiome...

Background: Microplastics are a pervasive pollutant widespread in the sea and freshwater from anthropogenic sources, and together with the presence of pesticides, they can have physical and chemical effects on aquatic organisms and on their microbiota. Few studies have explored the combined effects of microplastics and pesticides on the host-microb...

Ongoing climate change is leading to browning of many lakes and coastal areas, which can impair fish body growth and biomass production. However, whether and how effects of light limitation caused by browning on fish body growth vary over early ontogeny is unknown. In this study, we set up a mesocosm experiment to test whether roach (Rutilus rutilu...

Phenotypic plasticity is common among animal taxa. While there are clearly limits and likely costs to plasticity, these costs are unknown for most organisms. Further, as plasticity is partially genetically determined, the potential magnitude of exhibited plasticity may vary among individuals. In addition to phenotypic plasticity, various animal tax...

Citizen science data (CSD) have the potential to be a powerful scientific approach to assess, monitor and predict biodiversity. Here, we ask whether CSD could be used to predict biodiversity of recently constructed man-made habitats. Biodiversity data on adult dragonfly abundance from all kinds of aquatic habitats collected by citizen scientists (v...

The composition of intestinal microbiota commonly varies among animal hosts and may affect host health. However, we have limited knowledge about the different relative roles of assembly processes, such as drift, dispersal and environmental selection, for the composition of gut microbiota. Here, we conducted a field study analyzing intestinal microb...

Browning of waters, coupled to climate change and land use changes, can strongly affect aquatic ecosystems. Browning‐induced light limitation may have negative effects on aquatic consumers via shifts in resource composition and availability and by negatively affecting foraging of consumers relying on vision. However, the extent to which light limit...

Trophic cascades and other indirect effects can significantly mediate community interactions. Movement of energy between systems has been shown to be important for trophic cascades in food webs, where coupling between habitats can be important for food web stability and species evenness. To investigate the effects of habitat coupling on the stabili...

A major goal of evolutionary science is to understand how biological diversity is generated and altered. Despite considerable advances, we still have limited insight into how phenotypic variation arises and is sorted by natural selection. Here we argue that an integrated view, which merges ecology, evolution and developmental biology (eco evo devo)...

Speciation is the process that generates biodiversity, but recent empirical findings show that it can also fail, leading to the collapse of two incipient species into one. Here, we elucidate the mechanisms behind speciation collapse using a stochastic individual‐based model with explicit genetics. We investigate the impact of two types of environme...

Increased eye size in animals results in a larger retinal image and thus improves visual acuity. Thus, larger eyes should aid both in finding food as well as detecting predators. On the other hand, eyes are usually very conspicuous and several studies have suggested that eye size is associated with predation risk. However, experimental evidence is...

Predators should stabilize food webs because they can move between spatially separate habitats. However, predators adapted to forage on local resources may have a reduced ability to couple habitats. Here, we show clear asymmetry in the ability to couple habitats by Eurasian perch—a common polymorphic predator in European lakes. We sampled perch fro...

Stress as a consequence of anthropogenic interactions, habitat type or environmental changes, may affect the fitness and the proclivity of having parasitic organisms in populations of Gasterosteus aculeatus (Stickleback fish). Likewise, the ecotype (coming from lakes or water streams sources) might be related to the parasite colonization and theref...

Climate change studies have long focused on effects of increasing temperatures, often without considering other simultaneously occurring environmental changes, such as browning of waters. Resolving how the combination of warming and browning of aquatic ecosystems affects fish biomass production is essential for future ecosystem functioning, fisheri...

Interest in host-associated microbiomes has skyrocketed recently, yet our ability to explain microbiome variation has remained stubbornly low. Considering scales of interaction beyond the level of the individual host could lead to new insights. Metacommunity theory has many of the tools necessary for modeling multiscale processes and has been succe...

Contamination by microplastics (particles < 5mm) is a growing and alarming environmental problem in marine systems. Moreover, recent investigations show that freshwater systems might be already contaminated with similar levels as in marine systems. Evidence suggests that industrial effluents could be one of the critical points in the microplastics...

Background: Gut microbiota provide functions of importance to influence hosts' food digestion, metabolism, and protection against pathogens. Factors that affect the composition and functions of gut microbial communities are well studied in humans and other animals; however, we have limited knowledge of how natural food web factors such as stress f...

The risk of both predation and food level has been shown to affect phenotypic development of organisms. However, these two factors also influence animal behavior that in turn may influence phenotypic development. Hence, it might be difficult to disentangle the behavioral effect from the predator or resource-level effects. This is because the presen...

The microplastics are a pervasive pollutant, recognized as a world phenomenon spread in the sea- and freshwater by anthropogenic ways. Importantly, microplastics can interact and affect the fitness of many organisms in the environment. In fact, these microplastics are consumed and transported in all trophic levels and are accumulated during the lif...

Individual diet and habitat specialisation are widespread in animal taxa and often related to levels of predation and competition. Mobile consumers such as predatory fish can stabilise lake food webs by ranging over a larger area than their prey, thereby switching between habitats. Although, this switching assumes that the predator has equal prefer...

Many chemical and physical pollutants such as pesticides and microplastics are released every single day around the world. Eco-toxicological research has shown that some pesticides may also damage non-target organisms. In addition, microplastics are ubiquitous pollutants that are normally present in freshwaters and could be consumed by different or...

The ecological niche and mate preferences have independently been shown to be important for the process of speciation. Here, we articulate a novel mechanism by which ecological niche use and mate preference can be linked to promote speciation. The degree to which individual niches are narrow and clustered affects the strength of divergent natural s...

Increasing input of terrestrial dissolved organic carbon (DOC) has been identified as a widespread environmental phenomenon in many aquatic ecosystems. Terrestrial DOC influences basal trophic levels: it can subsidize pelagic bacterial production and impede benthic primary production via light attenuation. However, little is known about the impacts...

Gut microbiota is a key dimension of every single living macroorganism, playing an important symbiotic role in health, behavior and host evolution. The role of the host responses and host metabolism changes cannot be ignored. This is also important in the regulation of the bacterial gut colonization and in the impact that the gut microbiota might h...

Phenotypic plasticity is the ability of one genotype to produce different phenotypes depending on environmental conditions. Several conceptual models emphasize the role of plasticity in promoting reproductive isolation and, ultimately, speciation in populations that forage on two or more resources. These models predict that plasticity plays a criti...

A positive relationship between occupancy and average local abundance of species is found in a variety of taxa, yet the mechanisms driving this association between abundance and occupancy are still enigmatic. Here we show that freshwater fishes exhibit a positive abundance-occupancy relationship across 125 Swedish lakes. For a subset of 9 species f...

Among-individual diet variation is common in natural populations and may occur at any trophic level within a food web. Yet, little is known about its variation among trophic levels and how such variation could affect phenotypic divergence within populations. In this study we investigate the relationships between trophic position (the population’s r...

Individuals are constantly in competition with one another and, on both ecological and evolutionary timescales, processes act to reduce this competition and promote the gain of fitness advantages via diversification. Here we have investigated the genetic (AFLP) and morphological (geometric morphometrics) aspects of the littoral–pelagic axis, a comm...

Theory predicts that prey facing a combination of predators with different feeding modes have two options: to express a response against the feeding mode of the most dangerous predator, or to express an intermediate response. Intermediate phenotypes protect equally well against several feeding modes, rather than providing specific protection agains...

Vertebrates harbour diverse communities of symbiotic gut microbes. Host diet is known to alter microbiota composition, implying that dietary treatments might alleviate diseases arising from altered microbial composition ('dysbiosis'). However, it remains unclear whether diet effects are general or depend on host genotype. Here we show that gut micr...

Vertebrates' diets profoundly influence the composition of symbiotic gut microbial communities. Studies documenting diet-microbiota associations typically focus on univariate or categorical diet variables. However, in nature individuals often consume diverse combinations of foods. If diet components act independently, each providing distinct microb...

Background/Question/Methods There is extensive evidence that some species of ecological generalists, which use a wide diversity of resources, are in fact heterogeneous collections of relatively specialized individuals. This within-population variation, or ‘‘individual specialization,’’ is a key requirement for frequency-dependent interactions tha...

While phenotypic responses to direct species interactions are well studied, we know little about the consequences of indirect interactions for phenotypic divergence. In this study we used lakes with and without the zebra mussel to investigate effects of indirect trophic interactions on phenotypic divergence between littoral and pelagic perch. We fo...

Background / Purpose: Although costs and limits to phenotypic plasticity have been proposed as the impeding factors for the evolution to attain higher levels of plasticity, existing evidence suggests low costs. We propose a new explanation for the evolution of low plasticity in a sexually reproducing population with an evolving plastic magic trai...

Trait combinations that lead to a higher efficiency in resource utilization are important drivers of divergent natural selection and adaptive radiation. However, variation in environmental features might constrain foraging in complex ways and therefore impede the exploitation of critical resources. We tested the effect of water transparency on intr...

VIP scores of PLS analysis identifying the main factors related to morphological divergence. VIP is normalized, the average squared VIP value is 1. Terms in the model with a VIP>1 are important. (TIF)

Variables used in the PLS analysis. (DOCX)

Diet composition (%) of perch stomach content from A) littoral and B) pelagic fish. Other = Chaoborus sp., Rotatoria, fish, and terrestrial prey. (TIF)

Catch per unit effort (g m−2 net) for all surveyed lakes. (DOCX)

Biomass of pelagic (mg L−1) and benthic (mg m−2) resources for all surveyed lakes. (DOCX)

Correlation matrix of predictor variables with VIP>1. Shown are Pearson’s correlation coefficients. Significance levels *p<0.05, **p<0.01. (DOCX)

Background/Question/Methods Anthropogenic influences repeatedly lower visual conditions in aquatic environments through, for example, eutrophication. There is some evidence that habitat coupling is more pronounced and assortative mating is weakened in lakes with low visibility. Both of these factors, weakened assortative mating and stronger habit...

Phenotypic plasticity may be favored in generalist populations if it increases niche width, even in temporally constant environments. Phenotypic plasticity can increase the frequency of extreme phenotypes in a population and thus allow it to make use of a wide resource spectrum. Here we test the prediction that generalist populations should be more...

Intraguild predation--competition and predation by the same antagonist--is widespread, but its evolutionary consequences are unknown. Intraguild prey may evolve antipredator defenses, superior competitive ability on shared resources, or the ability to use an alternative resource, any of which may alter the structure of the food web. We tested for e...

Predation is a major driving force in evolution. Predation has been shown to select for size, morphology, and camouflage. Many animals use camouflage to reduce predation risk. In some cases, individuals can adjust their pigmentation, enabling them a higher survival in a heterogeneous environment. Here, we show that the difference in pigmentation be...

Background/Question/Methods The function of animals in food webs depends on their ability to mitigate conflicting demands such as finding resources and avoiding predators. This may lead to an alteration of the phenotypic expression of functional traits that can further feedback on the structure of the community. If the strength of competition and...

Background/Question/Methods Individual specialization is a widespread phenomenon in nature, observed in several taxa, both among vertebrates and invertebrates. Although its ecological and evolutionary implications are recognized, this type of intrapopulation variation is usually not considered in ecological studies. Furthermore, niche expansion is...

A key assumption of the ideal free distribution (IFD) is that there are no costs in moving between habitat patches. However, because many populations exhibit more or less continuous population movement between patches and traveling cost is a frequent factor, it is important to determine the effects of costs on expected population movement patterns...

The turnover and distribution of energy and nutrients in food webs is influenced by consumer stoichiometry. Although the stoichiometry of heterotrophs is generally considered to vary only little, there may be intraspecific variation due to factors such as habitat, resources, ontogeny and size. We examined intraspecific variation in Eurasian perch P...

Intraspecific competition has been shown to favor diet specialization among individuals. However, the question whether the competition takes the form of interference or exploitative in driving diet specialization has never been investigated. We investigated individual diet specialization in the isopod Saduria entomon, in relation to forager and res...

Predators are increasingly recognized as key elements in food webs because of their ability to link the fluxes of nutrients and energy between spatially separated food chains. However, in the context of food web connectivity, predator populations have been mainly treated as homogeneous units, despite compelling evidence of individual specialization...

Theoretical and empirical studies are showing evidence in support of evolutionary branching and sympatric speciation due to frequency‐dependent competition. However, phenotypic diversification due to underlying genetic diversification is only one possible evolutionary response to disruptive selection. Another potentially general response is phenoty...

Background/Question/Methods Predators are key elements in food webs because of their ability to link the fluxes of nutrients and energy between spatially separated food chains. In aquatic systems, littoral and pelagic habitats supply very different environments that can have strong influence on individual adaptations of predators and further conse...

A high degree of trophic polymorphism has been associated with the absence of high variability in population density. An explanation for this pattern is that density fluctuations may influence selective regime forms in populations. Still, only few studies have investigated evolutionary dynamics in fluctuating populations. Here we report on a multiy...

Theoretical and empirical studies are showing evidence in support of evolutionary branching and sympatric speciation due to frequency-dependent competition. However, phenotypic diversification due to underlying genetic diversification is only one possible evolutionary response to disruptive selection. Another potentially general response is phenoty...

Optimal foraging theory predicts that individuals should become more opportunistic when intraspecific competition is high and preferred resources are scarce. This density-dependent diet shift should result in increased diet breadth for individuals as they add previously unused prey to their repertoire. As a result, the niche breadth of the populati...

It has been hypothesized that inter-specific competition will reduce species niche utilization and drive morphological evolution in character displacement. In the absence of a competitor, intra-specific competition may favor an expansion of the species niche and drive morphological evolution in character release. Despite of this theoretical framewo...

There is extensive evidence that some species of ecological generalists, which use a wide diversity of resources, are in fact heterogeneous collections of relatively specialized individuals. This within-population variation, or “individual specialization,” is a key requirement for frequency-dependent interactions that may drive a variety of types o...

Traits determining ecological interactions and dynamics are generally subject to natural selection. That genetically based individual variation in ecological traits can influence population dynamics has interested population biologist from various perspectives. Population ecologists recognized the need to incorporate individual variation in models...

An increasing number of studies are showing evidence in support of sympatric speciation. One basic question remains, however. When a population has undergone a branching in its phenotype, is this due to an evolutionary branching in the underlying genotype or due to phenotypic plasticity modifying a single genotype? Thus, phenotypic plasticity has c...

Spatial and temporal heterogeneity in the environment is a common feature affecting many natural populations. For example, both the resource levels and optimal habitat choices of individuals likely change over time. One way for organisms to cope with environmental variation is to display adaptive plasticity in traits such as behavior and morphology...

Resource polymorphisms, intraspecific variation in morphology due to differential resource use, are common across a wide range of animal taxa. The focus in studies of such polymorphisms has been on external morphology, but the differential use of food resources could also influence other phenotypic traits such as the digestive performance. In the p...

Resource competition is thought to play a major role in driving evolutionary diversification. For instance, in ecological character displacement, coexisting species evolve to use different resources, reducing the effects of interspecific competition. It is thought that a similar diversifying effect might occur in response to competition among membe...

Resource competition has been hypothesized to be important in driving divergence by natural selection. The effect of competition on morphological divergence and plasticity has however rarely been investigated. Since low growth rates might constrain morphological modulation and individual growth rates usually are negatively related to the intensity...

Predators can cause a shift in both density and frequency of a prey phenotype that may lead to phenotypic divergence through natural selection. What is less investigated is that predators have a variety of indirect effects on prey that could potentially have large evolutionary responses. We conducted a pond experiment to test whether differences in...

Predators can cause a shift in both density and frequency of a prey phenotype that may lead to phenotypic divergence through natural selection. What is less investigated is that predators have a variety of indirect effects on prey that could potentially have large evolutionary responses. We conducted a pond experiment to test whether differences in...

Question: What is the importance of genetic variation and phenotypic plasticity in forming the morphological difference between littoral and pelagic perch? Organism: Juveniles of Eurasian perch (Perca fluviatilis L.). Site: Enclosures (2 × 2 m) in a pond, Röbäcksdalen, Umeå, Sweden. Methods: Adults from the littoral and pelagic habitats were bred s...