Search

Paleontologi etsii fossiiliaineistosta sukupuuttoon kuolleita muotoja ja tutkii, millaisia sukulaisuussuhteita niillä on nykyisiin muotoihin. Alkumuotona voidaan pitää fossiilia, joissa näkyy ensimmäistä kertaa rakenne, joka yleistyy myöhemmissä muodoissa. Nyt maapalloa hallitsee vain muutama nisäkäslaji, ja suurin osa alkumuotojen monimuotoisuudesta on hävinnyt tai häviämässä.

Kin selection on one hand, and gamete interactions in post-ejaculatory sexual selection on the other are two major research themes that have risen to prominence over the past half century and have simultaneously developed into central fields of research in evolutionary biology. There is a natural connection between the two: when gametes interact with each other, very commonly many of them originate from the same parent and are thus siblings. For example, sperm competition will almost always involve competition between sibling gametes even if the interacting parents are not related to each other. If parents are related to each other, the relatedness between gametes increases further. Here we discuss the relation between kin selection on one hand, and gamete competition, gamete limitation, local gamete competition, and the evolution of sex allocation on the other. To illustrate these topics, we present a novel model on sex allocation in simultaneous hermaphrodites under sperm limitation and limited, costly dispersal. We find that sperm limitation can significantly increase allocation into male function, but limited dispersal (and thus increased relatedness) does not alter sex allocation regardless of the presence of sperm limitation.

The aesthetic preferences of potential mates have driven the evolution of a baffling diversity of elaborate ornaments. Which fitness benefit—if any—choosers gain from expressing such preferences is controversial, however. Here, we simulate the evolution of preferences for multiple ornament types (e.g., “Fisherian,” “handicap,” and “indicator” ornaments) that differ in their associations with genes for attractiveness and other components of fitness. We model the costs of preference expression in a biologically plausible way, which decouples costly mate search from cost-free preferences. Ornaments of all types evolved in our model, but their occurrence was far from random. Females typically preferred ornaments that carried information about a male’s quality, defined here as his ability to acquire and metabolize resources. Highly salient ornaments, which key into preexisting perceptual biases, were also more likely to evolve. When males expressed quality-dependent ornaments, females invested readily in costly mate search to locate preferred males. In contrast, the genetic benefits associated with purely arbitrary ornaments were insufficient to sustain highly costly mate search. Arbitrary ornaments could nonetheless “piggyback” on mate-search effort favored by other, quality-dependent ornaments. We further show that the potential to produce attractive male offspring (“sexy sons”) can be as important as producing offspring of high general quality (“good genes”) in shaping female preferences, even when preferred ornaments are quality dependent. Our model highlights the importance of mate-search effort as a driver of aesthetic coevolution.

Interactions among symbiotic organisms and their hosts are major drivers of ecological and evolutionary processes. Monitoring the infection patterns among natural populations and identifying factors affecting these interactions are critical for understanding symbiont–host relationships. However, many of these interactions remain understudied since the knowledge about the symbiont species is lacking, which hinders the development of appropriate tools. In this study, we developed a digital droplet PCR (ddPCR) assay based on apicomplexan COX1 gene to detect an undescribed agamococcidian symbiont. We show that the method gives precise and reproducible results and enables detecting cryptic symbionts in low target concentration. We further exemplify the assay's use to survey seasonally sampled natural host (Pygospio elegans) populations for symbiont infection dynamics. We found that symbiont prevalence differs spatially but does not show seasonal changes. Infection load differed between populations and was low in spring and significantly increased towards fall in all populations. We also found that the symbiont prevalence is affected by host length and population density. Larger hosts were more likely to be infected, and high host densities were found to have a lower probability of infection. The observed variations could be due to characteristics of both symbiont and host biology, especially the seasonal variation in encounter rates. Our findings show that the developed ddPCR assay is a robust tool for detecting undescribed symbionts that are otherwise difficult to quantify, enabling further insight into the impact cryptic symbionts have on their hosts., Many symbiont‐host interactions are understudied due to the lack of knowledge about the symbiont species hindering the development of appropriate tools. Here, we developed a ddPCR assay to detect an undescribed agamococcidian symbiont in its host, Pygospio elegans, and show that the method enables detecting cryptic symbionts even in low target concentration. We further exemplify the assay's use to survey seasonally sampled natural host populations for symbiont infection dynamics.

The tardigrade genus Acutuncus has been long thought to be an Antarctic endemism, well adapted to this harsh environment. The Antarctic endemicity of Acutuncus was recently dispelled with the description of Acutuncus mariae Zawierucha, 2020 found in the Svalbard archipelago. The integrated analyses on two newly found Acutuncus populations from UK and Italy, and a population of Acutuncus antarcticus found close to its type locality allowed us to expand the climatic and geographic range of the genus Acutuncus. These findings also allowed us to re-evaluate the morphological diagnoses of Acutuncus and accommodate it in the newly proposed monotypic family Acutuncidae fam. nov. Two new Acutuncus species morpho-groups are instituted based on eggs morphology: one (Acutuncus antarcticus morphogroup) including the Antarctic Acutuncus taxa characterized by eggs with long pillars within the chorion and eggs laid freely to the environment, the other (Acutuncus mariae morphogroup) including the European species, characterized by eggs with short pillars within the chorion and eggs laid in the exuvium. Finally, we describe two new Acutuncus species from Europe: Acutuncus mecnuffi sp. nov. and Acutuncus giovanniniae sp. nov. peerReviewed

nonPeerReviewed

Publisher Copyright: Copyright © 2022 Hanhimäki, Watts, Koskela, Koteja, Mappes and Hämäläinen. Gut microbiota is expected to coevolve with the host's physiology and may play a role in adjusting the host's energy metabolism to suit the host's environment. To evaluate the effects of both evolved host metabolism and the environmental context in shaping the gut microbiota, we used a unique combination of (1) experimental evolution to create selection lines for a fast metabolism and (2) a laboratory-to-field translocation study. Mature bank voles Myodes glareolus from lines selected for high aerobic capacity (A lines) and from unselected control (C lines) were released into large (0.2 ha) outdoor enclosures for longitudinal monitoring. To examine whether the natural environment elicited a similar or more pronounced impact on the gut microbiota of the next generation, we also sampled the field-reared offspring. The gut microbiota were characterized using 16S rRNA amplicon sequencing of fecal samples. The artificial selection for fast metabolism had minimal impact on the gut microbiota in laboratory conditions but in field conditions, there were differences between the selection lines (A lines vs. C lines) in the diversity, community, and resilience of the gut microbiota. Notably, the selection lines differed in the less abundant bacteria throughout the experiment. The lab-to-field transition resulted in an increase in alpha diversity and an altered community composition in the gut microbiota, characterized by a significant increase in the relative abundance of Actinobacteria and a decrease of Patescibacteria. Also, the selection lines showed different temporal patterns in changes in microbiota composition, as the average gut microbiota alpha diversity of the C lines, but not A lines, was temporarily reduced during the initial transition to the field. In surviving young voles, the alpha diversity of gut microbiota was significantly higher in A-line than C-line voles. These results indicate that the association of host metabolism and gut microbiota is context-specific, likely mediated by behavioral or physiological modifications in response to the environment.

Maternal effects have the potential to alter early developmental processes of offspring and contribute to adaptive diversification. Egg size is a major contributor to offspring phenotype, which can influence developmental trajectories and potential resource use. However, to what extent intraspecific variation in egg size facilitates evolution of resource polymorphism is poorly understood. We studied multiple resource morphs of Icelandic Arctic charr, ranging from an anadromous morph—with a phenotype similar to the proposed ancestral phenotype—to sympatric morphs that vary in their degree of phenotypic divergence from the ancestral anadromous morph. We characterized variation in egg size and tested whether egg size influenced offspring phenotype at early life stages (i.e., timing of- and size at- hatching and first feeding [FF]). We predicted that egg size would differ among morphs and be less variable as morphs diverge away from the ancestral anadromous phenotype. We also predicted that egg size would correlate with offspring size and developmental timing. We found morphs had different egg size, developmental timing, and size at hatching and FF. Egg size increased as phenotypic proximity to the ancestral anadromous phenotype decreased, with larger eggs generally giving rise to larger offspring, especially at FF, but egg size had no effect on developmental rate. The interaction between egg size and the environment may have a profound impact on offspring fitness, where the resulting differences in early life-history traits may act to initiate and/or maintain resource morphs diversification. peerReviewed

Harvesting has been implicated in destabilizing the abundances of exploited populations. Because selective harvesting often targets large individuals, some studies have proposed that exploited populations often experience demographic shifts toward younger, smaller individuals and become more sensitive to environmental fluctuations. The theory of consumer–resource dynamics has been applied to address the impacts of harvesting in simple modular food webs, but harvested populations are embedded in a complex food web in nature. In addition, exploited populations have been shown to undergo trait evolution or phenotypic changes toward early maturation at smaller sizes. Using an empirically derived complex food web model, Kuparinen et al. (2016. Fishing-induced life-history changes degrade and destabilize harvested ecosystems. Scientific Reports: 6, 22,245) demonstrated that exploited fish populations and other ecosystem properties increased variability due to harvesting and harvesting-induced life-history evolution in the absence of environmental fluctuations. In the present study, we examined a large set of simulated complex food webs to attest the generality of the findings in Kuparinen et al. (2016). We found that harvesting both increased and decreased temporal variability of fish biomass dynamics, especially in food webs with intrinsically oscillating dynamics, while the vast majority of the food webs did not experience destabilization. We also elucidated the large impacts of the shape of functional responses on food web structure, energy flow, and changes in temporal variability caused by harvesting. Our results suggest that the destabilizing or stabilizing effects of harvesting and harvesting-induced evolution importantly depend on the shape of functional responses in dynamical models of complex food webs and that food webs with intrinsically oscillating dynamics are more prone to changes in temporal variability caused by harvesting and harvesting-induced evolution. peerReviewed

This is the peer reviewed version of the following article: "Circumpolar patterns of Arctic freshwater fish biodiversity: A baseline for monitoring", which has been published in final form at https://doi.org/10.1111/fwb.13405. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions Climate change, biological invasions, and anthropogenic disturbance pose a threat to the biodiversity and function of Arctic freshwater ecosystems. Understanding potential changes in fish species distribution and richness is necessary, given the great importance of fish to the function of freshwater ecosystems and as a resource to humans. However, information gaps limit large‐scale studies and our ability to determine patterns and trends in space and time. This study takes the first step in determining circumpolar patterns of fish species richness and composition, which provides a baseline to improve both monitoring and conservation of Arctic freshwater biodiversity. Information on species presence/absence was gathered from the Circumpolar Biodiversity Monitoring Program's Freshwater Database and used to examine patterns of freshwater fish γ‐, α‐, and β‐diversity across 234° of longitude in the Arctic. The metrics of diversity provided information on species richness and composition across hydrobasins, ecoregions, and Arctic zones. Circumpolar patterns of fish species biodiversity varied with latitude, isolation, and coarse ecoregion characteristics; patterns were consistent with historic and contemporary barriers to colonisation and environmental characteristics. Gamma‐diversity was lower in the high Arctic compared to lower latitude zones, but α‐diversity did not decrease with increasing latitude below 71°N, reflecting glacial history. Alpha‐diversity was reduced to a single species, Arctic charr Salvelinus alpinus, in ecoregions above 71°N, where γ‐diversity was the lowest. Beta‐diversity indicated little variation in the composition and richness of species across the High Arctic; at lower latitudes, ecoregions contained more species, although species composition turned over across large spatial extents. In an analysis of five ecoregions in the circumpolar Arctic, physical isolation, and ecoregion area and topography were identified as strong drivers of γ‐, α‐, and β‐diversity. Physical isolation reduced the γ‐ and α‐diversity, and changes in β‐diversity between adjacent locations were due mainly to losses in species richness, rather than due to differences in species composition. Heterogeneity of habitats, environmental gradients, and geographic distance probably contributed to patterns of fish dissimilarity within and across ecoregions. This study presents the first analysis of large‐scale patterns of freshwater fish biodiversity in the circumpolar Arctic. However, information gaps in space, time, and among taxonomic groups remain. Future inclusion of extensive archive and new data will allow future studies to test for changes and drivers of the observed patterns of biodiversity. This is important given the potential impacts of ongoing and accelerating climate change, land use, and biotic exchange on Arctic fish biodiversity.

Understanding fish population oscillations is important for both fundamental population biology and for fisheries science. Much research has focused on the causes of population oscillations, but the eco-evolutionary consequences of population oscillations are unclear. Here, we used an empirically parametrised individual-based simulation model to explore the consequences of oscillations with different amplitudes and wavelengths. We show that oscillations with a wavelength shorter than the maximum lifespan of the fish produce marked differences in the evolutionary trajectories of asymptotic length. Wavelengths longer than the maximum lifespan of the fish, in turn, mainly manifest as ecological effects seen as the population biomass oscillation. The evolutionary and ecological differences increase with increasing amplitude, however, the two-year wavelength causes opposing results from all the other scenarios. This is likely facilitated by the relatively stable number of fish in the population as a poor year is always counteracted by the previous good year and vice versa. Our results highlight the evolutionary signatures and following ecological consequences that natural population oscillations can cause. peerReviewed

Funding: This work was supported by Academy of Finland projects 268214 and 322980 to MK and a NERC (UK) grant NE/P000592/1 to MGR. Organisms can plastically alter resource allocation in response to changing environmental factors. For example, in harsh conditions, organisms are expected to shift investment from reproduction toward survival; however, the factors and mechanisms that govern the magnitude of such shifts are relatively poorly studied. Here we compared the impact of cold on males and females of the highly cold-tolerant species Drosophila montana at the phenotypic and transcriptomic levels. Although both sexes showed similar changes in cold tolerance and gene expression in response to cold treatment, indicating that the majority of changes are concordant between the sexes, we identified a clear reduction in sexually dimorphic gene expression, suggesting that preparing for the colder season involves reducing investment in sex-specific traits. This reduction was larger in males than females, as expected if male sexual traits are more condition-dependent than female traits, as predicted by theory. Gene expression changes were primarily associated with shifts in metabolic profile, which likely play a role in increasing cold tolerance. Finally, we found that the expression of immune genes was reduced following cold treatment, suggesting that reduced investment in costly immune function may be important in helping flies survive colder periods. Publisher PDF

Variation in stress responses has been investigated in relation to environmental factors, species ecology, life history and fitness. Moreover, mechanistic studies have unravelled molecular mechanisms of how acute and chronic stress responses cause physiological impacts (‘damage’), and how this damage can be repaired. However, it is not yet understood how the fitness effects of damage and repair influence stress response evolution. Here we study the evolution of hormone levels as a function of stressor occurrence, damage and the efficiency of repair. We hypothesise that the evolution of stress responses depends on the fitness consequences of damage and the ability to repair that damage. To obtain some general insights, we model a simplified scenario in which an organism repeatedly encounters a stressor with a certain frequency and predictability (temporal autocorrelation). The organism can defend itself by mounting a stress response (elevated hormone level), but this causes damage that takes time to repair. We identify optimal strategies in this scenario and then investigate how those strategies respond to acute and chronic exposures to the stressor. We find that for higher repair rates, baseline and peak hormone levels are higher. This typically means that the organism experiences higher levels of damage, which it can afford because that damage is repaired more quickly, but for very high repair rates the damage does not build up. With increasing predictability of the stressor, stress responses are sustained for longer, because the animal expects the stressor to persist, and thus damage builds up. This can result in very high (and potentially fatal) levels of damage when organisms are exposed to chronic stressors to which they are not evolutionarily adapted. Overall, our results highlight that at least three factors need to be considered jointly to advance our understanding of how stress physiology has evolved: (i) temporal dynamics of stressor occurrence; (ii) relative mortality risk imposed by the stressor itself versus damage caused by the stress response; and (iii) the efficiency of repair mechanisms. peerReviewed

A fundamental task of evolutionary biology is to explain the pervasive impression of organismal design in nature, including traits benefiting kin. Inclusive fitness is considered by many to be a crucial piece in this puzzle, despite ongoing discussion about its scope and limitations. Here we use individual‐based simulations to study what quantity (if any) individual organisms become adapted to maximise when genetic architectures are more or less suitable for the presumed main driver of biological adaptation: namely, cumulative multi‐locus evolution. As an expository device we focus on a hypothetical situation called Charlesworth’s paradox, in which altruism is seemingly predicted to evolve, yet altruists immediately perish along with their altruistic genes. Our results support a recently proposed re‐definition of inclusive fitness, which is concerned with the adaptive design of whole organisms as shaped by multi‐locus evolution, rather than with selection for any focal gene. They also illustrate how our conceptual understanding of adaptation at the phenotypic level should inform our choice of genetic assumptions in abstract simplified models. peerReviewed

Evidence of contemporary evolution across ecological time scales stimulated research on the eco‐evolutionary dynamics of natural populations. Aquatic systems provide a good setting to study eco‐evolutionary dynamics owing to a wealth of long‐term monitoring data and the detected trends in fish life‐history traits across intensively harvested marine and freshwater systems. In the present study, we focus on modelling approaches to simulate eco‐evolutionary dynamics of fishes and their ecosystems. Firstly, we review the development of modelling from single‐species to multispecies approaches. Secondly, we advance the current state‐of‐the‐art methodology by implementing evolution of life‐history traits of a top predator into the context of complex food web dynamics as described by the allometric trophic network (ATN) framework. The functioning of our newly developed eco‐evolutionary ATNE framework is illustrated using a well‐studied lake food web. Our simulations show how both natural selection arising from feeding interactions and size‐selective fishing cause evolutionary changes in the top predator and how those feed back to its prey species and further cascade down to lower trophic levels. Finally, we discuss future directions, particularly the need to integrate genomic discoveries into eco‐evolutionary projections. peerReviewed

The evolution and diversification of animal reproductive modes have been pivotal questions in behavioural ecology. Amphibians present the highest diversity of reproductive modes among vertebrates, involving various behavioural, physiological and morphological traits. One such feature is the amplexus, which is the clasp or embrace of males on females during reproduction and is found almost universally in anurans. Hypotheses about the origin of amplexus are limited and have not been tested thoroughly, nor have they taken into account evolutionary relationships in most comparative studies. However, these considerations are crucial to an understanding of the evolution of reproductive modes. Here, using an evolutionary framework, we reconstruct the ancestral state of amplexus in 685 anuran species. We investigate whether the type of amplexus has a strong phylogenetic signal and test whether sexual size dimorphism could have influenced amplexus type or male performance while clasping females. Overall, we found evidence of ≥34 evolutionary transitions in amplexus type across anurans. We found that amplexus type exhibits a high phylogenetic signal and that amplexus type does not evolve in association with sexual size dimorphism. We discuss the implications of our findings for the diversity of amplexus types across anurans. peerReviewed

The filamentous fungusNeurospora crassa, a model microbial eukaryote, has a life cycle with many features that make it suitable for studying experimental evolution. However, it has lacked a general tool for estimating relative fitness of different strains in competition experiments. To remedy this need, we constructedN. crassastrains that contain a modifiedcsr-1locus and developed an assay for detecting the proportion of the marked strain using a post PCR high resolution melting assay. DNA extraction from spore samples can be performed on 96-well plates, followed by a PCR step, which allows many samples to be processed with ease. Furthermore, we suggest a Bayesian approach for estimating relative fitness from competition experiments that takes into account the uncertainty in measured strain proportions. We show that there is a fitness effect of the mating type locus, as mating typemat ahas a higher competitive fitness thanmat A. Thecsr-1* marker also has a small fitness effect, but is still a suitable marker for competition experiments. As a proof of concept, we estimate the fitness effect of theqde-2mutation, a gene in the RNA interference pathway, and show that its competitive fitness is lower than what would be expected from its mycelial growth rate alone.

Biomass production and decomposition are key processes in ecology, where plants are primarily responsible for production and microbes act in decomposition. Trees harbor foliar microfungi living on and inside leaf tissues, epiphytes, and endophytes, respectively. Early researchers hypothesized that all fungal endophytes are parasites or latent saprophytes, which slowly colonize the leaf tissues for decomposition. While this has been proven for some strains in the terrestrial environment, it is not known whether foliar microfungi from terrestrial origin can survive or perform decomposition in the aquatic environment. On the other hand, aquatic hyphomycetes, fungi which decompose organic material in stream environments, have been suggested to have a plant-associated life phase. Our aim was to study how much the fungal communities of leaves and litter submerged in streams overlap. Ergosterol content on litter, which is an estimator of fungal biomass, was 5–14 times higher in submerged litter than in senescent leaves, indicating active fungal colonization. Leaves generally harbored a different microbiome prior to than after submergence in streams. The Chao1 richness was significantly higher (93.7 vs. 60.7, p = 0.004) and there were more observed operational taxonomic units (OTUs) (78.3 vs. 47.4, p = 0.004) in senescent leaves than in stream-immersed litter. There were more Leotiomycetes (9%, p = 0.014) in the litter. We identified a group of 35 fungi (65%) with both plant- and water-associated lifestyles. Of these, eight taxa had no previous references to water, such as lichenicolous fungi. Six OTUs were classified within Glomeromycota, known as obligate root symbionts with no previous records from leaves. Five members of Basidiomycota, which are rare in aquatic environments, were identified in the stream-immersed litter only. Overall, our study demonstrates that foliar microfungi contribute to fungal diversity in submerged litter.

Highlights • Mineral deposits influence water chemistry and composition of benthic communities. • Catchments with high potential for minerals and mining have unique stream communities. • Atypical background geology should be integrated in bioassessment of mining. Mining has changed landscapes locally in northern Fennoscandia and there is an increasing pressure for exploitation of the remaining mineral deposits of the region. Mineral deposits, even if unmined, can strongly influence stream water chemistry, stream biological communities and the ability of organisms to tolerate stressors. Using data sampled from six mining areas with three active (gold and chrome), two closed (gold) and one planned mine (phosphate), we examined how mineral deposits and mining influence water chemistry and diatom and macroinvertebrate communities in subarctic streams in Finnish Lapland. We supplemented the data by additional samples compiled from databases and further assessed how variation in background geological conditions influences bioassessments of the impacts arising from mining. We found that water specific conductivity was elevated in our study streams draining through catchments with a high mineral potential. Mining effects were mainly seen as increased concentration of nitrogen. Influence of mineral deposits was detected in composition of diatom and macroinvertebrate communities, but communities in streams in areas with a high mineral potential were as diverse as those in streams in areas with a low mineral potential. Mining impacts were better detected for diatoms using a reference condition based on sites with a high than low mineral potential, while for macroinvertebrates, the responses were generally less evident, likely because of only minor effects of mining on water chemistry. Community composition and frequencies of occurrence of macroinvertebrate taxa were, however, highly similar between mine-influenced streams and reference streams with a high potential for minerals indicating that the communities are strongly structured by the natural influence of mineral deposits. Incorporating geochemistry into the reference condition would likely improve bioassessments of both taxonomic groups. Replicated monitoring in potentially impacted sites and reference sites would be the most efficient framework for detecting environmental impacts in streams draining through mineral-rich catchments.

Intensive fishing that selects for large and old individuals can have pervasive effects on traits directly associated with the fecundity and survival of the target species. The observed reduction in fish body size can result in earlier sexual maturity at a smaller body size, leading to a lower individual reproductive output and population productivity in the long term. In addition, increased predation can induce similar responses in age and size at maturity due to the release of intraspecific competition and the lower population density. Thus, the combined impact of fisheries and predation is more difficult to predict due to their competition for fish, ultimately limiting and directing the prey size selectivity of each competitor. This can lead to various responses of fish on individual and population levels, depending on how the impacts of fisheries and predation affect each other. To explore this topic, we used an individual-based model to investigate the responses of the European hake (Merluccius merluccius) to the coupled pressures of the prevailing fishing regime and predation by bottlenose dolphins (Tursiops truncatus) as a study system. By simulating the growth trajectories of hake with consideration to its pronounced sexual size dimorphism (SSD), we applied Holling’s Type II and III functional responses (FRII and FRIII, respectively) and the Rosenzweig-MacArthur predator model to describe prey–predator dynamics. Our results demonstrate how the intensity, duration, and prey sizes selected by predation and fisheries determine the potential for evolutionary changes in hake life-history traits. Additionally, pronounced SSD in hake as well as the predation type play a pivotal role in hake resilience and recovery following a period of overexploitation. Different types of predation reveal the discrepancy in the intensity of competition between predators and fisheries for fish, as well as predator survival, which is relevant for sustainable fisheries management and effective predator conservation strategies.

This article aims to reveal the political positioning of ‘mire nature’ in Finnish peatland policy and law. The data analysed include the latest policy documents, laws and regulations related to mires and peat extraction. Analysis is based on frame analysis (i.e. how an object is defined and positioned) and ideas drawn from a political ecology approach. Two main frames can be identified within the Finnish legal and policy framework: peat as a natural resource to be utilised for national energy sufficiency and economic competitiveness, and peat as a valuable source of biodiversity and an integral element of global ecosecurity. Analysis reveals the degree to which the definition of issues or objects in legal and policy terms is important in determining outcomes. It also reveals that national policies have swung back and forth and are prone to economic power struggles. Furthermore, while laws and regulations have offered strong and longstanding support for the extractive use of peat, the latest regulatory developments show a break from this trend. However, the arguments and facts concerning climate change are poorly integrated with Finnish peatland policy and law.

Metsien avainbiotooppien merkitystä epifyyttijäkälille selvitettiin kirjallisuuskatsauksen avulla. Avainbiotooppien merkitys riippuu siitä, miten ne määritetään sekä kuinka hyvin ne tunnistetaan ja jätetään hakkuiden ulkopuolelle. Avainbiotooppikäsite on potentiaalisesti hyvä epifyyttijäkälille tärkeiden metsien säästämisessä. Eri avainbiotooppityyppien merkitys epifyyttijäkälille on varsin erilainen. Puuston korkea ikä on vaateliaiden epifyyttijäkälien kannalta tärkein muuttuja. Tutki­musten mukaan avainbiotooppikäsitteen soveltaminen ei ole onnistunut hyvin. Suurimmat ongelmat ovat kohteiden tunnistamisessa, säästämisessä sekä niiden pienessä koossa. Hakkuiden ja pienen koon takia vaateliaiden epifyyttijäkälien esiintymien häviämiset ovat olleet avain­biotoopeilla varsin tavallisia. Häviämistä lisäävät ilmansaasteet ja ylisuuri hirvieläinkanta, joka estää lehtipuiden uusiutumista avainbiotoopeilla. Samat tekijät, jotka aiheuttavat populaatioiden häviämistä, estävät myös uusien jäkäläpopulaatioiden leviämistä avainbiotoopeille. Tässä katsauksessa käsiteltyjen tutkimusten perusteella voidaan arvioida, että jos avainbiotoopit säästettäisiin kaikilta hakkuilta, ilmanlaatua saataisiin parannettua ja hirvieläinten määrää voimakkaasti vähennettyä, suuri osa uhanalaisista jäkälistä voisi säilyä avainbiotoopeilla. Yhdessä riittävän suojelualueverkoston kanssa avainbiotoopit voisivat olla tehokas tapa epifyyttijäkälien monimuotoisuuden säilyttämisessä. Suomessa käytettyä avainbiotooppien määrittelyä on tarpeen korjata vastaamaan muissa maissa käytettyä uhanalaisen lajiston esiintymisen todennäköisyyttä painottavaa tulkintaa sen sijaan, että korostettaisiin kohteen pienialaisuutta.

Rapid environmental fluctuations are ubiquitous in the wild, yet majority of experimental studies mostly consider effects of slow fluctuations on organism. To test the evolutionary consequences of fast fluctuations, we conducted nine independent experimental evolution experiments with bacteria. Experimental conditions were same for all species, and we allowed them to evolve either in fluctuating temperature alternating rapidly between 20°C and 40°C or at constant 30°C temperature. After experimental evolution, we tested the performance of the clones in both rapid fluctuation and in constant environments (20°C, 30°C and 40°C). Results from experiments on these nine species were combined meta-analytically. We found that overall the clones evolved in the fluctuating environment had evolved better efficiency in tolerating fluctuations (i.e., they had higher yield in fluctuating conditions) than the clones evolved in the constant environment. However, we did not find any evidence that fluctuation-adapted clones would have evolved better tolerance to any measured constant environments (20°C, 30°C, and 40°C). Our results back up recent empirical findings reporting that it is hard to predict adaptations to fast fluctuations using tolerance curves. © 2018 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. peerReviewed

Prey strategically respond to the risk of predation by varying their behavior while balancing the tradeoffs of food and safety. We present here an experiment that tests the way the same indirect cues of predation risk are interpreted by bank voles, Myodes glareolus, as the game changes through exposure to a caged weasel. Using optimal patch use, we asked wild-caught voles to rank the risk they perceived. We measured their response to olfactory cues in the form of weasel bedding, a sham control in the form of rabbit bedding, and an odor-free control. We repeated the interviews in a chronological order to test the change in response, i.e., the changes in the value of the information. We found that the voles did not differentiate strongly between treatments pre-exposure to the weasel. During the exposure, vole foraging activity was reduced in all treatments, but proportionally increased in the vicinity to the rabbit odor. Post-exposure, the voles focused their foraging in the control, while the value of exposure to the predator explained the majority of variation in response. Our data also suggested a sex bias in interpretation of the cues. Given how the foragers changed their interpretation of the same cues based on external information, we suggest that applying predator olfactory cues as a simulation of predation risk needs further testing. For instance, what are the possible effective compounds and how they change “fear” response over time. The major conclusion is that however effective olfactory cues may be, the presence of live predators overwhelmingly affects the information voles gained from these cues. Significance statement In ecology, “fear” is the strategic response to cues of risk an animal senses in its environment. The cues suggesting the existence of a predator in the vicinity are weighed by an individual against the probability of encounter with the predator and the perceived lethality of an encounter with the predator. The best documented such response is variation in foraging tenacity as measured by a giving-up density. In this paper, we show that an olfactory predator cue and the smell of an interspecific competitor result in different responses based on experience with a live-caged predator. This work provides a cautionary example of the risk in making assumptions regarding olfactory cues devoid of environmental context. peerReviewed

Aim: Understanding the relative contribution of different species interactions in shaping community assembly has been a pivotal aim in community ecology. Biotic interactions are acknowledged to be important at local scales, although their signal is assumed to weaken over longer distances. We examine the relationship between positive, neutral and negative pairwise bird abundance distributions and the phylogenetic and functional distance between these pairs after first controlling for habitat associations. Location: France and Finland. Time period: 1984 to 2011 (Finland), 2001 to 2012 (France). Major Taxa studied: Birds. Methods: We used results from French and Finnish land bird monitoring programmes, from which we created three independent datasets (French forests, French farmlands and Finnish forests). Separately for the three datasets, we fitted linear mixed-effects models for pairwise abundance values across years per point count station to infer the association between all common species pairs, while controlling for geographical distribution and habitat associations, and saved pairwise regression coefficients for further analyses. We used a null model approach to infer whether the observed associations (effect sizes) differ from random. Finally, using quantile regression, we analysed the relationships between functional dissimilarity/phylogenetic distance and effect sizes. Results: Our results show both negative and positive species interactions, although negative interactions were twice as common as positive interactions. Closely related species were more likely to show strong associations, both negative and positive, than more distant species across broad spatial scales. For functional dissimilarity, the results varied across datasets. Main conclusions: Our results emphasize the potential of functional and phylogenetic proximity in generating both negative and positive species associations, which can produce pervasive patterns from local to geographical scales. Future assembly studies should refrain from strict dichotomies, such as compensatory dynamics versus environmental forcing, and instead consider the possibility of positive interactions. peerReviewed

Sota, rauha ja rakkaus ovat ihmisen kulttuurin ytimessä. Ne kuvaavat voimakkaita tunnetiloja ja keskeisiä käyttäytymismalleja, joita kohdistetaan oman tai muiden ryhmien jäseniin. Mutta esiintyvätkö nämä ilmiöt luonnossakin ja miten ne mahdollisesti liittyvät ihmisen evoluutioon? Entä muiden eliöiden, kuten muurahaisten, runsasväkiset yhteiskunnat? Ohjaavatko näitä samat pelisäännöt kuin ihmisen yhteisöjä?

One of the main questions in evolutionary biology is what causes genetic differentiation among populations and the origin of new species. In this thesis I studied genetic differentiation of populations by testing how changes in the environment and behaviour have affected populations of Myrmica ants (Formicidae, Hymenoptera). First, I used a phylogeographic approach to find out how climatic changes during and after the last glaciation have affected populations of two Palearctic ant species Myrmica rubra and M. ruginodis. The aim was to locate their glacial refugia and postglacial recolonization routes, and to test whether differences in their cold tolerance and life-history traits have affected their phylogeographic structures and locations of their glacial refugia. Second, I studied the effect of behavioural differences on populations of M. rubra. I examined genetic differentiation and reproductive isolation of an intraspecific microgynous social parasite and its macrogynous host using both genetic and behavioural approaches. The aim was to clarify whether social parasitism as an alternative reproductive tactic may lead to speciation in sympatry. The results of this thesis show that differences in life-history traits have had no effect on the phylogeographic structures of M. rubra and M. ruginodis. Both species have survived the last glaciation in several refugia in Southern Europe but probably also in regions further east and north. Circumstantial evidence suggests that the more cold-tolerant M. ruginodis has survived in refugia more north than M. rubra. Both species have recolonized the northern areas from the south-west and south-east, and probably also from the east. Both genetic and behavioural evidence suggested that in M. rubra the parasite and host are reproductively isolated. They differed substantially in their nuclear DNA, indicating that the parasite is in the process of speciation. However, the mitochondrial lineages of the host and the parasite have not yet diverged. This thesis brings new information on the history of Palearctic insects and the effects of the past environmental changes on their populations. This thesis also clarifies the evolution of social parasitism and provides new evidence for a probable example of sympatric speciation through an alternative reproductive tactic, social parasitism. Yksi evoluutiobiologian tärkeimmistä kysymyksistä on, mikä aiheuttaa populaatioiden geneettistä erilaistumista ja uusien lajien syntymistä. Tutkin väitöskirjatyössäni tekijöitä, jotka vaikuttavat populaatioiden geneettiseen erilaistumiseen ja selvitin, miten elinympäristön ja käyttäytymisen muutokset ovat vaikuttaneet Myrmica-suvun muurahaisten (Formicidae, Hymenoptera) populaatioihin. Ensiksi tutkin fylogeografisten menetelmien avulla elinympäristön muutosten vaikutusta kahden Palearktisen muurahaislajin, siloviholaisen (Myrmica rubra) ja ryppyviholaisen (M. ruginodis), populaatioihin. Tavoitteenani oli paikallistaa lajien jääkauden aikaiset refugiot (turvapaikat) ja jääkauden jälkeiset leviämisreitit, sekä selvittää, miten erot lajien kylmänkestävyydessä ja elinkierrossa ovat vaikuttaneet niiden fylogeografiseen rakenteeseen ja refugioiden sijaintiin. Toiseksi, tutkin käyttäytymiserojen vaikutuksia siloviholaispopulaatioihin. Selvitin lajinsisäisen sosiaalisen mikrogyyniloisen ja sen makrogyyniemännän geneettisen erilaistumisen määrää ja lisääntymisisolaatiota tutkimalla sekä niiden genetiikkaa että käyttäytymistä. Tavoitteenani oli selvittää, voiko sosiaalinen loisinta vaihtoehtoisena lisääntymistaktiikkana johtaa lajiutumiseen. Erot lajien elinkierrossa eivät ole vaikuttaneet niiden fylogeografiseen rakenteeseen. Molemmat lajit ovat selviytyneet viimeisen jääkauden aikana useassa refugiossa Etelä-Euroopassa, mutta myös itäisemmillä ja pohjoisemmilla alueilla. Kylmänkestävämpi ryppyviholainen on luultavasti selviytynyt pohjoisemmissa refugioissa kuin siloviholainen. Lajit ovat todennäköisesti levinneet jääkauden jälkeen pohjoiseen lounaasta, kaakosta sekä luultavasti myös idästä. Sekä genetiikkaan että käyttäytymiseen perustuvat tulokset viittaavat siihen, että loisen ja sen emännän välillä on lisääntymisisolaatio. Niiden tuman DNA poikkesi merkitsevästi toisistaan ja loinen on luultavasti lajiutumassa emännästään. Loisen ja emännän mitokondrion DNA:n linjat eivät kuitenkaan ole vielä eriytyneet toisistaan. Väitöskirjatyöni tuo uutta tietoa Palearktisten hyönteisten historiasta ja siitä, miten elinympäristön muutokset ovat vaikuttaneet niiden populaatioihin viimeisen jääkauden aikana ja sen jälkeen. Työni valaisee sosiaalisen loisinnan evoluutiota ja antaa uusia viitteitä sympatrisesta lajiutumisesta tilanteessa, jossa lajiutumisen syynä on vaihtoehtoinen lisääntymistaktiikka, sosiaalinen loisinta.

Speciation on islands is affected by island size and the range of habitats and resources available and often also by limited interactions with other taxa. An ancestral population may evolve into a large number of species via an adaptive radiation. In Madagascar, most groups of animals and plants have radiated on the island, having arrived via oceanic dispersal during the long isolation of Madagascar. Characteristic features of Malagasy biota are exceptionally high level of endemism, high species richness as well as lack of many higher taxa that are dominant on the African mainland. Malagasy dung beetles are dominated by two tribes, Canthonini and Helictopleurina, with more than 250 endemic species. In this thesis I have reconstructed molecular phylogenies for the two tribes using several gene regions and different phylogenetic methods. Evolution of closely related species and among populations of the same species was examined with haplotype networks. The Malagasy Canthonini consists of three large lineages, while Helictopleurina forms a monophyletic group. The ancestors of each of the four clades colonised Madagascar at different times during Cenozoic. The subsequent radiations differ in terms of the number of extant species (from 37 to more than 100) and the level of ecological differentiation. In addition, Onthophagini (6 species) and Scarabaeini (3) have colonised Madagascar several times, but they have not radiated and the few species have not entered forests where Canthonini and Helictopleurina mostly occur. Among the three Canthonini radiations, speciation appears to have been mostly allopatric in the oldest and the youngest clades, while in the Epactoides clade sister species have diverged in their ecologies but have similar geographical distributions, indicating that speciation may have occurred in regional sympatry. The most likely isolating mechanisms have been rivers and forest refugia during dry and cool geological periods. Most species are generalists feeding on both carrion and dung, and competition among ecologically similar species may prevent their coexistence in the same communities. Some species have evolved to forage in the canopy and a few species have shifted to use cattle dung, a new resource in the open habitats following the introduction of cattle 1500 years ago. The latter shift has allowed species to expand their geographical ranges. Madagaskarin eläin- ja kasvilajisto on hyvin rikas, ja suurin osa lajeista on kotoperäisiä, eli ne ovat kehittyneet saarella ja ne esiintyvät vain siellä. Pääosin nykylajiston kantamuodot ovat saapuneet saarelle meriteitse kymmeniä miljoonia vuosia sitten saaren jo ollessa erkaantunut Afrikan mantereesta. Lajit ovat syntyneet saarella ja sopeutuneet sen moniin erilaisiin ympäristöihin. Toisaalta, eristyneisyytensä takia Madagaskarilta puuttuu monia eläinryhmiä, jotka esiintyvät runsaina manner-Afrikassa. Erityispiirteidensä ansiosta Madagaskar on oivallinen alue tutkia lajiutumista ja lajiryhmien kehittymistä. Madagaskarilta tunnetaan yli 250 kotoperäistä lantakuoriaislajia. Suurin osa lajeista kuuluu Canthonini- ja Helictopleurina-sukuryhmiin. Väitöskirjatutkimuksessani olen selvittänyt madagaskarilaisten lantakuoriaisten evoluutiota rakentamalla useaan geenialueeseen perustuvia sukupuita. Lajistoltaan suurempi sukuryhmistä, Canthonini, koostuu kolmesta erillisestä kehityslinjasta Kunkin linjan kantamuoto on saapunut saarelle viimeisen 65 miljoonan vuoden aikana. Helictopleurina-ryhmällä on vain yksi kantamuoto, joka saapui saarelle noin 30 miljoonaa vuotta sitten. Nämä neljä lantakuoriaislinjaa eroavat toisistaan lajimääriltään (37 yli 100 lajiin) sekä monilta ekologisilta piirteiltään. Suurin osa lajeista ei ole erikoistunut eri ravintoihin, mutta kahdella vanhimmalla linjalla on monipuolisempi ravinto kuin nuoremmilla ryhmillä. Kaikki neljä linjaa esiintyvät useissa metsätyypeissä, mutta erityisesti sademetsäalueella, jossa niille on parhaiten tarjolla ravintoa. Jotkin lajeista ovat kehittyneet asumaan puiden latvustossa, kun taas muutama laji on siirtynyt käyttämään lehmänlantaa avoimilla alueilla. Kumpikin näistä muutoksista on tapahtunut useaan kertaan. Lehmänlannan käyttö on mahdollistanut näiden lajien levittäytymisen koko saarelle, sillä karjaa kasvatetaan ympäri saarta. Saarella esiintyy myös Onthophagini- ja Scarabaeini-sukuryhmien lantakuoriaislajeja, mutta nämä ryhmät eivät ole pystyneet lajiutumaan saarella lähes lainkaan eivätkä leviämään sademetsiin. Todennäköisesti ne ovat saapuneet saarelle myöhemmin kuin Canthonini- ja Helictopleurina-ryhmät, ja kilpailu näiden aiemmin kehittyneiden ja siten saarelle paremmin sopeutuneiden lajien kanssa on estänyt uudempien ryhmien levittäytymisen.

Mutation and recombination are the fundamental processes leading to genetic variation in natural populations. This variation forms the raw material for evolution through natural selection and drift. Therefore, studying mutation rates may reveal information about evolutionary histories as well as phylogenetic interrelationships of organisms. In this thesis two molecular tools, DNA barcoding and the molecular clock were examined. In the first part, the efficiency of mutations to delineate closely related species was tested and the implications for conservation practices were assessed. The second part investigated the proposition that a constant mutation rate exists within invertebrates, in form of a metabolic-rate dependent molecular clock, which can be applied to accurately date speciation events. DNA barcoding aspires to be an efficient technique to not only distinguish between species but also reveal population-level variation solely relying on mutations found on a short stretch of a single gene. In this thesis barcoding was applied to discriminate between Hylochares populations from Russian Karelia and new Hylochares findings from the greater Helsinki region in Finland. Although barcoding failed to delineate the two reproductively isolated groups, their distinct morphological features and differing life-history traits led to their classification as two closely related, although separate species. The lack of genetic differentiation appears to be due to a recent divergence event not yet reflected in the beetles molecular make-up. Thus, the Russian Hylochares was described as a new species. The Finnish species, previously considered as locally extinct, was recognized as endangered. Even if, due to their identical genetic make-up, the populations had been regarded as conspecific, conservation strategies based on prior knowledge from Russia would not have guaranteed the survival of the Finnish beetle. Therefore, new conservation actions based on detailed studies of the biology and life-history of the Finnish Hylochares were conducted to protect this endemic rarity in Finland. The idea behind the strict molecular clock is that mutation rates are constant over evolutionary time and may thus be used to infer species divergence dates. However, one of the most recent theories argues that a strict clock does not tick per unit of time but that it has a constant substitution rate per unit of mass-specific metabolic energy. Therefore, according to this hypothesis, molecular clocks have to be recalibrated taking body size and temperature into account. This thesis tested the temperature effect on mutation rates in equally sized invertebrates. For the first dataset (family Eucnemidae, Coleoptera) the phylogenetic interrelationships and evolutionary history of the genus Arrhipis had to be inferred before the influence of temperature on substitution rates could be studied. Further, a second, larger invertebrate dataset (family Syrphidae, Diptera) was employed. Several methodological approaches, a number of genes and multiple molecular clock models revealed that there was no consistent relationship between temperature and mutation rate for the taxa under study. Thus, the body size effect, observed in vertebrates but controversial for invertebrates, rather than temperature may be the underlying driving force behind the metabolic-rate dependent molecular clock. Therefore, the metabolic-rate dependent molecular clock does not hold for the here studied invertebrate groups. This thesis emphasizes that molecular techniques relying on mutation rates have to be applied with caution. Whereas they may work satisfactorily under certain conditions for specific taxa, they may fail for others. The molecular clock as well as DNA barcoding should incorporate all the information and data available to obtain comprehensive estimations of the existing biodiversity and its evolutionary history. Mutaatiot ja geneettinen rekombinaatio ovat luonnonpopulaatioiden perinnöllisen muuntelun perusta. Evoluutio muovaa tätä ainesta luonnonvalinnan ja ajautumisen kautta. On ilmeistä, että mutaatiofrekvenssin tutkiminen valaisee niin evoluution kulkua kuin eliöiden sukulaisuussuhteita. Tässä väitöskirjassa tutkittiin kahta molekyylibiologien työkalua, DNA-viivakoodia ja molekyylikelloa. Työn ensimmäisessä osassa tarkasteltiin eri geenialueiden kykyä luonnehtia lähisukuisia lajeja ja tämän kysymyksen merkitystä luonnonsuojelubiologiassa. Työn toisessa osassa tutkittiin hypoteesia, jonka mukaan hyönteisten mutaatiofrekvenssi noudattaa molekyylikelloa. Kohteena oli erityisesti hypoteesi, jonka mukaan molekyylikellon tarkkuutta voi parantaa huomioimalla eri lajien lämpötila. DNA-viivakoodauksella otaksutaan voitavan erottaa lajeja toisistaan tietyn geenialueen avulla. Tutkimuksessa verrattiin Suomesta hiljattain uudelleen löydetyn kovakuoriaisen, haapasepikän ja lajin venäläisten yksilöiden geenialueita keskenään. Kaikki yksilöt osoittautuivat identtisiksi jokaisen tutkitun geenialueen suhteen. Toisaalta suomalaiset ja venälaiset yksilöt erosivat toisistaan niin elintapojensa kuin rakenteensa suhteen. Suomessa laji kehittyi kovapuisissa halavissa ja mustuvapajuissa, Venäjällä suurissa lahoavissa haavoissa. Suomalaiset yksilöt olivat myös hiukan hoikkarakenteisempia kuin venäläiset ja molempien muotojen koiraiden sukupuolielimet olivat selvästi toisistaan eroavat. Näillä perusteilla Suomesta kuvattu laji piti vanhan tieteellisen nimensä, Hylochares cruentatus (Gyllenhal), mutta suomeksi se ristittiin uudelleen halavasepikäksi. Haapasepikän nimi jätettiin maamme rajojen ulkopuolella elävälle lajille, joka kuvattiin tieteelle uutena nimellä Hylochares populi Brüstle -- Muona. Haapasepikän biologiaa ei tunnettu Suomesta, koska siitä tiedettiin vain kaksi hyvin vanhaa löytöä. Lajin katsottiin hävinneen maastamme suurten haapojen myötä, elihän se tällaisissa puissa Venäjän Karjalassa. Havainnot Suomessa osoittivat, että olettamus oli virheellinen. Kyse oli kahdesta eri lajista, joiden elintavat erosivat toisistaan selvästi. Luonnonsuojelubiologian kannalta tämä oli tärkeä havainto. DNA-viivakoodin tutkiminen ei pystynyt osoittamaan kahden lajin olemassaoloa. Aiempi päättely Karjalan havaintojen kelpoisuudesta Suomen lajin suojeluun oli myös virheellinen. Halavasepikkä on ilmeisesti hyvin hiljan eriytynyt haapasepikän sisarlaji, joka tunnetaan vain Suomesta. Kaikki vanhat havainnot Suomen ulkopuolelta koskevat haapasepikkää. Halavasepikkä on saimaannorpan kaltainen, kotoperäinen suomalainen eläin. Molekyylikellon ajatuksena on, että mutaatiot kertyvät tietylle geenialueelle vakionopeudella ja näin makromolekyylien erojen perusteella voidaan päätellä evolutiivisten haarautumien ikä. Tätä kellon hypoteesia on tarkennettu eri tavoin myöhemmin. Sen sijaan, että kello tikittää vakionopeudella, otaksutaan sen noudattavan hienovaraisempia sääntöjä. Hiljan esitetyn hypoteesin mukaan kello ei tikitä vain aikayksikköä kohden. Ajan ohella mutaatiot kertyvät suhteessa eliön lämpötilasta ja massasta riippuvaan aineenvaihduntaenergiaan. Tämän hypoteesin mukaan molekyylikello tulee kalibroida huomioiden eliön paino ja lämpötila. Tässä tutkimuksen osassa selvitettiin lämpötilan vaikutusta mutaatiofrekvenssiin tasakokoisilla lajeilla. Käytössä oli kaksi eri aineistoa. Ensimmäinen näistä oli pantrooppinen sepiköiden heimoon kuuluva a kovakuoriaissuku Arrhipis. Ennen kellohypoteesin tutkimista myös Arrhipis-lajien sukulaisuussuhteet selvitettiin. Toinen aineisto koostui kukkakärpäsistä, joiden fylogenia oli selvitetty aiemmin. Molempia aineistoja tutkittiin eri analyysimenetelmin, usean geenin suhteen ja kokeillen useaa kellohypoteesia. Tulokset osoittivat, että lämpötilalla ja mutaatiofrekvenssillä ei ollut yhteyttä tutkituilla eliöillä. Näin ollen lämmöstä riippuvaa aineenvaihduntaenergia-hypoteesin mukaista molekyylikelloa ei havaittu. Tulosten mukaan on suhtauduttava varovaisuudella kelloon perustuviin molekyylibiologisiin menetelmiin. Ne voivat toimia tietyissä tilanteissa tietyillä eliöillä, mutta pettää toisessa tilanteessa. Sovellettaessa molekyylikelloa ja DNA-viivakoodausta monimuotoisuuden ja evolutiivisen historian tutkimuksessa on syytä käyttää mahdollisimman laajasti saatavilla olevaa muuta tietoa ja välttää yksinkertaistettuja ratkaisuja.

Understanding the overwhelming diversity of life calls for complex organisational schemes. The field of systematics may thus be seen as the cornerstone of evolutionary biology. In the last few decades, systematics has been rejuvenated through the introduction of molecular methods such as DNA barcoding and multi-gene phylogenetic approaches. These methods may shed new light on established taxonomic ideas and problems. For example, the classification of ants has aroused much debate due to reinterpretation of morphological characters or contradictions between molecular data and morphology. Only in the last few years a consensus was reached regarding the phylogeny of ant subfamilies. However, the situation remains deplorable for lower taxonomic ranks such as subfamilies, tribes and genera. This thesis describes the systematics and evolution of the Holarctic ant genus Myrmica and the tribe to which it belongs, Myrmicini. Using barcoding, molecular-phylogenetic data and divergence time estimations, it addresses questions regarding the taxonomy, morphology and biogeography of this group. Furthermore, the interrelationships between socially parasitic Myrmica species and their hosts (other species in the genus) were inferred. The phylogeny suggests that social parasitism evolved several times in Myrmica. Finally, this thesis investigated whether coevolution shaped the phylogeny of socially parasitic Maculinea butterflies that live inside Myrmica colonies. No evidence was found for coevolution. Muurahaiset ovat eräitä biosfäärin tärkeimpiä ja laajimmalle levittäytyneimpiä hyönteisiä. Myrmica-suvun muurahaiset (viholaiset) ovat yleisiä koko pohjoisella pallonpuoliskolla. Sukuun kuuluu useita sosiaalisia loisia, lajeja, jotka eivät noudata normaalia muurahaisten kolonian kiertokulkua, vaan loisivat suvun muilla lajeilla. Sosiaaliset loiset tunkeutuvat toisten muurahaislajien kolonioihin ja käyttävät niiden työläisiä omien jälkeläistensä kasvattamiseen, osallistumatta itse lainkaan kolonian ylläpitoon. Maculinea-suvun sinisiipiperhoset ovat myös viholaisten sosiaalisia loisia. Perhosten toukat elävät muurahaisten pesissä, jossa niitä joko ruokitaan tai ne syövät itse muurahaisten toukkia. Väitöskirjassani olen käyttänyt nykyaikaisia DNA-menetelmiä, kuten DNA-viivakoodausta ja fylogenetiikkaa Pohjois-Amerikan viholaisten keskinäisten sukulaisuussuhteiden selvittämiseen sekä Pohjois-Amerikan ja muun maailman viholaisten geneettiseen vertailuun. Päättelin DNA-ajoitusmenetelmien perusteella, että Myrmica-suvun muurahaislajit ovat runsastuneet todennäköisesti dramaattisen ilmaston kylmenemisen seurauksena noin 34 miljoonaa vuotta sitten. Tämän jälkeen viholaiset ovat levittäytyneet useita kertoja Beringin salmen yli Pohjois-Amerikan ja Itä-Aasian välillä. Tutkin lisäksi Myrmica-suvun sosiaalisten loisten ja niiden isäntien keskinäisiä sukulaisuussuhteita ja havaitsin, että sosiaaliset loiset ovat kehittyneet suvussa useaan kertaan. Lopuksi tutkin viholaisten ja niiden sosiaalisten sinisiipiperhosloisten mahdollista rinnakkaisevoluutiota, josta en löytänyt todisteita.

Interactions among individuals give rise to both cooperation and conflict. Individuals will behave selfishly or altruistically depending on which gives the higher payoff. The reproductive strategies of many animals are flexible and several alternative tactics may be present from which the most suitable one is applied. Generally, alternative reproductive tactics may be defined as a response to competition from individuals of the same sex. These alternative reproductive tactics are means by which individuals may fine-tune their fitness to the reigning circumstances and which are shaped by the environment individuals are occupying as well as by the behaviour of other individuals sharing the environment. By employing such alternative ways of achieving reproductive output, individuals may alleviate competition from others. Conspecific brood parasitism (CBP) is an alternative reproductive strategy found in several egg laying animal groups, and it is especially common among waterfowl. Within this alternative reproductive strategy, four reproductive options can be identified. These four options represent a continuum from low reproductive effort coupled with low fitness returns, to high reproductive effort and consequently high benefits. It may not be evident how individuals should allocate reproductive effort between eggs laid in their own nest vs. in nests of others, however. Limited fecundity will constrain the number of eggs donated by a parasite, but also the tendency for hosts to accept parasitic eggs may affect the allocation decision. Furthermore, kinship, individual quality and the costs of breeding may play a role in complicating the allocation decision. In this thesis, I view the seemingly paradoxical effects of kinship on conflict resolution in the context of alternative reproductive tactics, examining the resulting features of cooperation and conflict. Conspecific brood parasitism sets the stage for investigating these questions. By using both empirical and theoretical approaches, I examine the nature of CBP in a brood parasitic duck, the Barrow's goldeneye (Bucephala islandica). The theoretical chapter of this thesis gives rise to four main conclusions. Firstly, variation in individual quality plays a central role in shaping breeding strategies. Secondly, kinship plays a central role in the evolution of CBP. Thirdly, egg recognition ability may affect the prevalence of parasitism. If egg recognition is perfect, higher relatedness between host and parasite facilitates CBP. Finally, I show that the relative costs of egg laying and post-laying care play a so far underestimated role in determining the prevalence of parasitism. The costs of breeding may outweigh possible inclusive fitness benefits accrued from receiving eggs from relatives. Several of the patterns brought out by the theoretical work are then confirmed empirically in the following chapters. Findings include confirmation of the central role of relatedness in determining the extent of parasitism as well as inducing a counterintuitive host clutch reduction. Furthermore, I demonstrate a cost of CBP inflicted on hosts, as well as results suggesting that host age reflects individual quality, affecting the ability to overcome costs inflicted by CBP. In summary, I demonstrate both theoretically and empirically the presence of cooperation and conflict in the interactions between conspecific parasites and their hosts. The field of CBP research has traditionally been divided, but the first steps have now been taken toward the acceptance of the opposite side of the divide. Especially the theoretical findings of chapter 1 offer the possibility to view seemingly contrasting results of various studies within the same framework, and may direct future research toward more general features underlying differences in the patterns of CBP between populations or species. Knipor kan få mer avkomma genom att lägga ägg i andra knipors bon. Mottagaren måste dock ta hand om en större kull ungar, vilket är krävande. Därför kallas fenomenet kullparasitism. Denna avhandling studerar effekterna av kullparasitism på värdhonors häckningsframgång samt konflikt- och samarbetssituationer relaterade till kullparasitism. Denna studie följde islandsknipor i Västra Kanadas ödemarker under fyra häckningssäsonger. Vart annat bo innehöll parasitägg. Även om kullparasitism är vanligt hos knipor och andra andfåglar är detta en mycket hög grad av parasitism. Kullparasitism innebär kostnader för värdar och de överger sina bon om för många parasit ägg läggs i deras kullar. Knipor tycks dock tolerera sina parasiterande släktingar och sköter deras ungar tills de är flygfärdiga. Parasiterna tycks veta var deras släktingar häckar. Ju närmare släkt parasiten är med dess värd desto fler ägg lade parasiten. Även avståndet mellan parasitens eget bo och värdboet hade en effekt på antalet ägg som lades. Värdbon nära parasitens bo fick mer parasitägg än mer avlägsna bon. Som följd av parasitism lade värdhonor färre ägg i sina bon, som om de gav rum för släktingars parasitägg. Kullparasitism studerades även med hjälp av en matematisk modell för att klargöra när parasitism är skadligt och när det kan vara fördelaktigt. Resultaten visade att kullparasitism parasit kan leda till ömsesidiga fördelar om värd och parasit är besläktade. Detta beror på att den som hjälper sin släkting att föröka sig får själv fördelar. Det lönar sig för värdar att förkasta parasitägg om parasiten inte är en släkting. Resultaten av denna forskning visar att kullparasitism mellan individer av samma art är en konflikt som kan lösas genom släktskap. Då värd och parasit är släktingar kunde kullparasitism vara samarbete.

Jordens ekologiska system undergår för tillfället stora förändringar pga. människans aktiviteter. Ett växande antal studier visar att dessa förändringar påverkar naturliga och sexuella urvalet och därmed evolutiva processer. Målet med detta arbete var att undersöka effekterna av omgivningsförändringar på sexuella urvalet genom att använda den ökade övergödningen inom storpiggen Gasterosteus aculeatus lekområden som modell system. Sexuella urvalet är en viktig evolutiv kraft med följder på populations- och artnivå (Kapitel 1). Avhandlingens olika delar fokuserar på övergödningens effekter på upptäckandet av partners, användningen av visuella- och doftsignaler i partnersval, och fördelningen av parningsframgången mellan bobyggande hanar. I Kapitel II och III simuleras hur grumlighet orsakad av fytoplankton påverkar hastigheten med vilken potentiella partners påträffas, genom effekter på synligheten. Resultaten visar att normala algblomningar i Östersjön har en måttlig effekt på finnandet av potentiella partners. Detta tyder på att algblomningarna troligen inte kommer att minska på selektiva parningen pga. ökade sökkostnader. I Kapitel IV visas att storspiggen ändrar relativa användningen av olika signaler när vattnets grumlighet ökar; visuella signaler minskar i betydelse medan doftsignaler ökar i betydelse. Samtidigt underlättas användandet av doftsignaler av ändringar i vattnets kemiska sammansättning då fotosyntesen intensifieras (Kapitel V). Lek i övergödda vatten kan ändå vara kostsamt både på individ- och populationsnivån, då parasiterade hanar, som troligen är dåligt genetiskt anpassade till sin miljö, lyckas få mer ägg i sina bon än friskare hanar som troligen är av högre genetisk kvalitet (Kapitel VI). Övergödningen påverkar således partnersval och konkurrensen om partners genom att påverka upptäckandet av potentiella partners, evalueringen av partners och fördelningen av partners inom lekområdena. De följder detta kan ha för evolutionen av sexuellt selekterad egenskaper och för populationers dynamik och livskraft är dock oklara. Avhandlingen visar på svårigheten att förutse följderna av omgivningsförändringar för sexuella urvalet och effekterna på individ och populationsnivå. The increasing ecological footprint of the human population alters ecosystems worldwide. A growing number of studies reveal that human-induced changes interfere with natural and sexual selection. The aim of this thesis was to determine how environmental change alters sexual selection by using eutrophication of the breeding habitats of the threespine stickleback Gasterosteus aculeatus as a model system. Sexual selection is an important evolutionary process, with consequences at individual, population and species level (Chapter I). The different parts of the thesis focus on the influence of eutrophication on mate detection, the use of visual and olfactory mate choice cues, and the distribution of mating success among nesting males. In Chapter II and III, we simulate how phytoplankton turbidity decreases mate encounter rate by constraining the visual range. We show that the reduction in mate encounter rate is moderate at the breeding grounds in the Baltic Sea at normal spring bloom turbidity values. This suggests that phytoplankton turbidity is unlikely to decrease assortative mating due to increased search costs. Chapter IV shows that sticklebacks alter the use of cues used in mate choice when visibility decreases, reducing the use of visual cues and increasing the use of olfactory cues. Moreover changes in the water chemistry in eutrophied areas, caused by intensified photosynthetic production, seem to facilitate the use of olfactory cues (Chapter V). However, a field experiment revealed that breeding in eutrophied waters could be costly at both the individual and the population level, since more parasitized males received more eggs in eutrophied waters, although these males most likely are of low genetic quality (Chapter VI). Eutrophication clearly affects mate choice and mate competition by influencing mate detection, mate assessment and the distribution of mates on the breeding grounds, but the consequences this may have on sexual selection on traits and ultimately on population dynamics and persistence remain unclear. The thesis shows the difficulty in predicting the consequences of human-induced environmental change on sexual selection at the individual and the population level.

Tähtien sota -elokuvan ensimmäisessä episodissa "Pimeä uhka" nuori Anakin Skywalker, josta myöhemmin tulee hirmuinen Darth Vader, ajautuu erilaisten kohtalon käänteiden kautta jediritarin oppilaaksi. Jediritari Qui-Gon Jinn aavistaa, että nuoressa Anakin-pojassa on jotain erikoista. Voima on vahvana hänessä, kuten olimme jo aikaisempien "Tähtien sota" -elokuvien yhteydessä oppineet toteamaan. Mutta episodissa "Pimeä uhka" mennään pidemmälle, mielenkiintoisiin yksityiskohtiin.

Oxfordin yliopiston professori, evoluutiobiologi William D. Hamilton sai akateemikon arvonimen Helsingissä viime marraskuussa. Jos joku ihmettelee, että "kuka ihmeen Hamilton", niin siinä ei ole mitään uutta. Hamiltonin ura nimittäin alkoi hieman takellellen. Tämä siitäkin huolimatta, että biologian teoreetikko Richard Dawkinsin mukaan hän on niitä ihmisiä, joilla on tapana olla oikeassa.

There are intricate links between the evolution of sociality and the spatial population structures created by dispersal. In ants, the evolution of the most complex societies, supercolonies, is strongly connected to limited dispersal. The supercolonies consist of hundreds of interconnected nests where thousands of queens and their workers cooperate over large areas. Supercolonies arise from simpler family units when large proportions of daughter queens are philopatric and stay in their natal colony as additional reproducing queens instead of dispersing by wing. This allows the colonies to grow quickly and colonize large areas, but also increases social conflicts due to very low local relatedness in these societies. In this thesis I inspect the evolution and maintenance of ant supercolonies, by focusing on dispersal traits and the consequences of dispersal in socially polymorphic Formica ants. Formica have both simple family-based monodomous colonies and complex supercolonies, and some species have also intraspecific variation. To lay a sound theoretical background for my work, I began by synthesizing current knowledge of dispersal evolution in ants. In my literature review I showed how eco-evolutionary feedbacks link the evolution of ant dispersal strategies and social organization, and pinpointed the most relevant future research directions. Next, to be able to inspect some of the hypotheses formulated in the review, I clarified the species identification of one of my intended study species, Formica fennica with molecular methods, and concluded that the populations I studied should be treated as conspecific to Formica exsecta. I analyzed the individual dispersal traits of six socially variable species of Formica ants to assess whether dispersal ability varies between monodomous and supercolonial societies in accordance to the observed behavioral difference. According to my results the dispersal behavior of these species is likely not restricted by their morphology or resources the individuals get from their natal colonies. The traits of all species and both sexes indicate good flight ability, with overall male bias and large variation both among and within species. The increased philopatry in supercolonial species and populations is more a behavior change: the queens are philopatric even though the society provides them resources for dispersal. However, I observed a small decrease of male flight muscle ratio in supercolonial species, which indicates strong coevolution of the sexes. In order to better understand the outcomes of limited dispersal in supercolonial Formica, I analyzed the behavioral and genetic structure of a dense supercolonial population of Formica pressilabris. The population is genetically viscous at a small spatial scale, but still not genetically structured by location on a larger spatial scale. This indicates that although dispersal is limited within the population, a large enough proportion of individuals do disperse to keep the local populations connected. Interestingly, when analyzing worker behavior among the polydomous nests, the observed aggression pattern indicates that they are not a single cooperative unit – but also not clearly separate colonies. The sensitive behavioral assay developed for this study shows that workers allow a proportion of individuals from outside nests to enter their own nest material, but are slightly more aggressive towards individuals from further away. This indicates the population is only partially cooperative over the whole nest aggregation, and shows that the inner structures of supercolonies should be analyzed in more detail. This thesis sheds light on ants’ dispersal ability and behavior, and demonstrates the crucial role of dispersal in the evolution of their different social structures. My results also raise new questions about possible conflicts over dispersal in ant societies. Sosiaalisuuden evoluutio linkittyy vahvasti siihen, kuinka eliöt hajaantuvat elinympäristöönsä levittäytymisen seurauksena. Muurahaisten monimutkaisimpien yhteiskuntien, superkolonioiden, evoluutio on yhteydessä rajoittuneeseen levittäytymiseen. Superkoloniat koostuvat sadoista toisiinsa yhteydessä olevista pesistä, joissa tuhannet kuningattaret ja niiden työläiset tekevät yhteistyötä laajoilla alueilla. Superkoloniat syntyvät yksinkertaisemmista perheyksiköistä, kun suuri osuus tytärkuningattarista jää synnyinkoloniaansa ylimääräisiksi lisääntyviksi kuningattariksi sen sijaan, että lentäisivät muualle. Tämän seurauksena yhteiskunnat voivat kasvaa nopeasti ja suurille alueille, mutta samalla sosiaaliset ristiriidat lisääntyvät, koska paikallinen sukulaisuus laskee hyvin alas. Tässä väitöskirjassa tutkin superkolonioiden evoluutiota ja toimintaa sosiaalisesti monimuotoisilla suomumuurahaisilla (Formica), keskittyen levittäytymisominaisuuksiin ja levittäytymisen seurauksiin. Formica-muurahaisilla on sekä yksipesäisiä perheryhmiin perustuvia kolonioita että monimutkaisia superkolonioita, ja joillakin lajeilla on myös lajinsisäistä vaihtelua. Luodakseni työlleni vahvan teoreettisen pohjan, aloitin kokoamalla yhteen nykytietämyksen muurahaisten levittäytymisen evoluutiosta. Kirjallisuuskatsauksessani osoitan kuinka eko-evolutiiviset takaisinkytkennät liittävät levittäytymisstrategioiden evoluution ja sosiaalisen rakenteen toisiinsa. Hahmottelen myös tärkeimpiä tulevaisuuden tutkimussuuntia. Voidakseni tutkia katsausartikkelissa muotoilemiani hypoteeseja, varmistin suomenloviniskan (Formica fennica) lajintunnistuksen molekulaarisin metodein. Totesin, että geneettisen samankaltaisuuden vuoksi tutkimuspopulaatioitani tulee käsitellä karvaloviniskan (Formica exsecta) kanssa samaan lajiin kuuluvina. Analysoin kuuden sosiaalisesti erilaisen Formica-lajin yksilöiden levittäytymisominaisuuksia selvittääkseni, vaihteleeko niiden yksipesäisten ja superkoloniaalisten yhteiskuntien levittäytymiskyky samalla tavalla kuin niiden levittäytymiskäyttäytymisen tiedetään vaihtelevan. Osoitan, että näiden lajien käyttäytyminen ei todennäköisesti riipu yksilöiden morfologiasta tai resursseista, joita ne saavat synnyinkolonioiltaan. Kaiken kaikkiaan jokaisen tutkimani lajin ominaisuudet viittaavat siihen, että sekä koiraat että kuningattaret osaavat lentää hyvin. Koirailla on parempi lentokyky kuin kuningattarilla, ja sekä lajien välillä että lajien sisällä yksilöiden välillä on suurta vaihtelua. Se, että superkoloniaalisten lajien kuningattaret jäävät synnyinkoloniaan on siis käyttäytymispiirre: ne jäävät, vaikka yhteiskunta antaa niille tarvittavat resurssit levittäytymiseen. Havaitsin kuitenkin, että superkoloniaalisilla lajeilla koiraiden lentolihasten koko on pienentynyt, mikä viittaa sukupuolten yhteisevoluutioon. Ymmärtääkseni rajoittuneen levittäytymisen seurauksia superkoloniaalisilla Formicoilla, analysoin rämeloviniskan (Formica pressilabris) tiiviin, superkoloniaalisen populaation käyttäytymistä ja geneettistä rakennetta. Osoitan, että populaation sisällä läheiset pesät ovat geneettisesti samankaltaisempia kuin kaukaisemmat pesät, mutta että suuremmassa mittakaavassa populaatiot eivät silti eroa geneettisesti toisistaan. Tämä viittaa siihen, että vaikka levittäytyminen on rajoittunutta populaation sisällä, tarpeeksi suuri joukko yksilöitä silti lentää alueelta toiselle, ja suuremmassa mittakaavassa populaatiot ovat yhteydessä toisiinsa. Superkolonian sisäisen käyttäytymisen analysoiminen osoitti mielenkiintoisen seikan: työläisten vaihtelevasti aggressiivinen käytös viittaa siihen, että kaikki pesät eivät kuulu samaan yhteistyössä olevaan yksikköön - mutta pesien välille on silti mahdoton osoittaa selkeitä rajoja. Tätä tutkimusta varten kehitetty herkkä käyttäytymisanalyysi osoittaa, että työläiset sallivat muiden pesien työläisten tulla omalle pesämateriaalilleen, mutta ovat hiukan aggressiivisempia mitä kauempaa vierailijat ovat peräisin. Tämä viittaa siihen, että populaatio on vain osittain yhteistyössä koko pesärykelmän alalla. Formica-superkolonioiden sisäistä rakennetta pitäisi jatkossa tutkia aiempaa yksityiskohtaisemmin. Tämä väitöskirja valottaa muurahaisten levittäytymiskykyä ja -käyttäytymistä, sekä näyttää kuinka vahvasti levittäytyminen liittyy sosiaalisten rakenteiden evoluutioon. Tulokseni herättävät myös uusia kysymyksiä levittäytymiseen mahdollisesti liittyvistä ristiriidoista muurahaisyhteiskunnissa.

Human-caused habitat changes have led to declines of many species by impairing their occurrence, reproduction and interactions with other species. In Northern Europe, intensive forestry has transformed boreal forests and worsened conditions of species dependent on old forest, but the mechanisms by which habitat changes affect species are often unknown. In my dissertation, I examined habitat changes, their effects and habitat-associated breeding performances of three declining forest-dwelling hawks, the northern goshawk (Accipiter gentilis), the common buzzard (Buteo buteo) and the honey buzzard (Pernis apivorus). These species can compete for nest sites and goshawks can also predate the buzzards. Raptors may lack nest sites in managed forests which is why their nesting has been supported by constructing artificial nests. I analysed the breeding success of the hawks in artificial nests since their benefits as a conservation measure were not previously analysed. Finally, I studied the conditions when dominant species can exclude subordinate ones in competition for suitable nest sites. According to my results, old forests have decreased and young forests increased throughout southern Finland. These changes are adverse for the goshawk whose breeding success improves when old spruce forests are more abundant and young forests scarce around their nests. Breeding performances of the common buzzard and honey buzzard were not significantly associated with habitats. However, common buzzards were reluctant to re-occupy nests surrounded by a vastness of old forest. The breeding success of the goshawk and common buzzard was lower in artificial nests than in natural ones. Thus, this measure aimed at enabling hawk breeding in managed forests seems to conflict with its conservation objectives. I discuss the possible contributing factors and directions for further investigations. Interspecific interactions with other raptors proved to be important when a subordinate hawk decided on territory occupancy. Common buzzards prefer to occupy safe territories, where threats of goshawk predation and interference competition with other raptors are small. Thus, interspecific raptors that are predators or competitors may exclude subordinate raptors from their territories, and thereby contribute to their occurrence. Adverse interactions with other raptors may even impede a subordinate raptor from fully exploiting the periodic food peaks. My dissertation shows that for each species, it is crucial to identify the most relevant spatiotemporal scales in order to identify, how external disturbances affect them most. Long-term data is of paramount importance to detect these scales. Ihmisen aiheuttamat elinympäristömuutokset ovat monien lajien taantumisen suurin syy, sillä ne vaikuttavat lajien esiintymiseen, lisääntymiseen sekä lajienvälisiin vuorovaikutuksiin. Pohjois-Euroopassa tehometsätalous on muokannut boreaalisia metsiä ja heikentänyt erityisesti vanhojen metsien lajien elinoloja. Elinympäristömuutosten vaikutusmekanismeja ei kuitenkaan aina tunneta. Tutkin väitöskirjassani kolmen vähentyneen metsäpetolinnun, kanahaukan (Accipiter gentilis), hiirihaukan (Buteo buteo) ja mehiläishaukan (Pernis apivorus), elinympäristön muutoksia, muutosten vaikutuksia sekä pesimistulokseen vaikuttavia elinympäristötekijöitä. Lajit voivat kilpailla pesäpaikoista, mutta kanahaukka voi myös saalistaa hiiri- ja mehiläishaukkoja. Talousmetsissä haukoille sopivia pesäpaikkoja on niukasti, joten pesintää on avustettu rakentamalla tekopesiä. Tutkin haukkojen pesimistulosta tekopesissä, joiden hyötyjä suojelutoimenpiteenä ei ole tarkasteltu. Lisäksi tutkin, missä oloissa vahvemmat lajit voivat syrjäyttää alisteiset lajit sopivilta pesäpaikoilta. Tulosteni mukaan vanhat metsät vähentyivät haukkojen reviireillä ja Etelä-Suomessa, kun taas nuorten metsien osuus kasvoi. Nämä muutokset ovat haitallisia etenkin kanahaukalle, jonka pesimismenestys kasvaa vanhan kuusimetsän osuuden kasvaessa ja nuoren metsän osuuden vähentyessä reviirillä. Hiiri- ja mehiläishaukalla ei havaittu merkitsevää yhteyttä elinympäristön ja pesimistuloksen välillä. Hiirihaukat eivät kuitenkaan mielellään asuttaneet uudestaan pesiään, joiden ympärillä oli paljon vanhaa metsää. Kanahaukan ja hiirihaukan pesimismenestys oli alhaisempi tekopesissä kuin haukkojen omissa pesissä. Haukkojen avuksi ajateltu suojelukeino vaikuttaa siten olevan ristiriidassa suojelutavoitteidensa kanssa. Tarkastelen tähän mahdollisesti vaikuttavia tekijöitä sekä tarvittavia lisäselvityksiä. Vuorovaikutussuhteet muiden petolintulajien kanssa osoittautuivat tärkeiksi alisteisen petolintulajin päättäessä asettumisesta reviirille. Hiirihaukka suosii turvallisia reviirejä, joilla uhat kanahaukan saalistuksesta ja muiden petolintulajien häirinnästä ovat pieniä. Hallitsevat petolintulajit voivat siten syrjäyttää alisteisen petolintulajin reviiriltä ja vaikuttaa sen esiintymiseen ja kannankokoon. Epäedulliset vuorovaikutukset muiden petolintulajien kanssa voivat jopa estää alisteista petolintulajia hyödyntämästä täysimääräisesti saalislajiensa ajoittaisia huippuvaiheita. Väitöskirjani osoittaa, että on tärkeää tunnistaa kullekin lajille oleelliset alueelliset ja ajalliset mittakaavat, jotta tiedetään, millä tavalla ulkoiset häiriöt vaikuttavat lajiin eniten. Lajien pitkäaikaisaineistot ovat ensiarvoisen tärkeitä näiden mittakaavojen selvittämiseksi.

Most studies of life history evolution are based on the assumption that species exist at equilibrium and spatially distinct separated populations. In reality, this is rarely the case, as populations are often spatially structured with ephemeral local populations. Therefore, the characteristics of metapopulations should be considered while studying factors affecting life history evolution. Theoretical studies have examined spatial processes shaping the evolution of life history traits to some extent, but there is little empirical data and evidence to investigate model predictions. In my thesis I have tried to bridge the gap between theoretical and empirical studies by using the well-known Glanville fritillary (Melitaea cinxia) metapopulation as a model system. The long-term persistence of classic metapopulations requires sufficient dispersal to establish new local populations to compensate for local extinctions. Previous studies on the Glanville fritillary have shown that females establishing new populations are not a random sample from the metapopulation, but they are in fact more dispersive than females in old populations. Many other life-history traits, such as body size, fecundity and lifespan, may be related to dispersal rate. Therefore, I examined a range of correlated traits for their evolutionary and ecological consequences. I was particularly interested in how the traits vary under natural environmental conditions, hence all studies were conducted in a large (32 x 26 m) outdoor population cage built upon a natural habitat patch. Individuals for the experiments were sampled from newly-established and old populations within a large metapopulation. Results show that females originating from newly-established populations had higher within-habitat patch mobility than females from old populations. I showed that dispersal rate is heritable and that flight activity is related to variation in a gene encoding the glycolytic enzyme phosphoglucose isomerase. Both among-individual and among-population variation in dispersal are correlated with the reproductive performance of females, though I found no evidence for a trade-off between dispersal and fecundity in terms of lifetime egg production or clutch size. Instead, the results suggest that highly dispersive females from newly-established populations have a shorter lifespan than females from old populations, and that dispersive females may pay a cost in terms of reduced lifetime reproductive success due to increased time spent outside habitat patches. In summary, the results of this thesis show that genotype-dependent dispersal rate correlates with other life history traits in the Glanville fritillary, and that the rapid turnover of local populations (extinctions and re-colonisations) is likely to be the mechanism that maintains phenotypic variation in many life history traits at the metapopulation level. Perinteisissä elinkiertoekologisissa tutkimuksissa oletetaan usein, että lajit esiintyvät toisistaan erillisinä, yksittäisinä populaatioina. Todellisuudessa tämä olettamus pitää vain harvoin paikkansa. Populaatioiden välillä on usein vuorovaikutusta yksilöiden liikkuessa yhdestä populaatiosta toiseen. Metapopulaatioiden erityispiirteet tulisi siis ottaa huomioon myös elinkiertoekologisissa tutkimuksissa. Teoreettisissa tutkimuksissa populaatioiden tilarakenne on jossain määrin huomioitu, mutta näitä teoreettisia tarkasteluja on vain harvoin pyritty testaamaan empiirisesti. Väitöskirjatyössäni olenkin pyrkinyt kuromaan umpeen aukkoa teoreettisten ja empiiristen tutkimusten välillä käyttäen apuna paljon tutkittua täpläverkkoperhosmetapopulaatiota Ahvenanmaalla. Yksittäisillä paikallispopulaatioilla on suuri sukupuutoriski. Metapopulaation selviytymisen edellytyksenä on uusien paikallispopulaatioiden syntyminen, jonka mahdollistaa yksilöiden kyky liikkua elinympäristölaikkujen välillä. Aiemmat täpläverkkoperhostutkimukset ovatkin osoittaneet, että uusissa paikallispopulaatioissa esiintyvät naaraat eivät ole sattumanvarainen otos metapopulaatiosta, vaan uusien populaatioiden naarailla on parempi liikkumiskyky kuin vanhojen populaatioiden naarailla. Väitöskirjatyössäni tutkin mahdollisia korrelaatioita liikkuvuuden ja muiden elinkiertoekologisten ominaisuuksien, kuten ruumiin koon, lisääntymismenestyksen ja eliniän välillä sekä pyrin ymmärtämään näiden korrelaatioiden ekologisen ja evolutiivisen merkityksen. Olen erityisen kiinnostunut ominaisuuksien vaihtelusta luonnonmukaisissa olosuhteissa, minkä vuoksi kokeet suoritettiin lajin luontaisen elinympäristön päälle rakennetussa populaatiohäkissä (32 x 26 m). Tulokset osoittivat, että myös populaatiohäkissä uusien populaatioiden naaraat liikkuivat enemmän kuin vanhojen populaatioiden naaraat. Osoitin myös, että liikkuvuus on periytyvä ominaisuus ja että lentoaktiivisuuteen vaikuttaa vaihtelu geenissä, joka koodaa glykolyysissä tärkeää fosfoglukoosi-isomeraasi -entsyymiä. Sekä populaatioiden sisäinen että niiden välinen vaihtelu liikkuvuudessa korreloi naaraiden lisääntymismenestyksen kanssa. En kuitenkaan havainnut usein oletettua, liikkuvuudesta aiheutuvaa fysiologista elinkiertokustannusta naaraiden elinikäisessä munatuotannossa. Liikkuvuuden kustannukset näkyivät uusien populaatioiden naaraiden lyhyempänä elinikänä. Suuremmalla liikkuvuudella on kuitenkin metapopulaatiotasolla kustannus, sillä liikkuvammat naaraat viettävät enemmän aikaa elinympäristön ulkopuolella, minkä vuoksi niillä on vähemmän aikaa lisääntymiseen kuin vähemmän liikkuvilla naarailla. Väitöskirjatyöni tulokset osoittavat, että paikallispopulaatioiden nopea vaihtuvuus (sukupuutot ja uusien paikallispopulaatioiden syntyminen) Ahvenanmaan täpläverkkoperhosmetapopulaatiossa ylläpitää vaihtelua useissa elinkiertoekologisissa ominaisuuksissa liikkuvuuden ohella.