To Örebro University

This book traces the history of how evolutionary biology transformed its understanding of females from being coy, reserved and sexually passive, to having active sexual strategies and often mating with multiple males. Why did it take so long to discover female active sexual strategies? What prevented some researchers from engaging in sexually active females, and what prompted others to develop this new knowledge?

The Female Turn provides a global overview of shifting perceptions about females in sexual selection research on a wide range of animals, from invertebrates to primates. Evolutionary biologist and feminist science scholar Malin Ah-King explores this history from a unique interdisciplinary vantage point. Based on extensive knowledge of the scientific literature on sexual selection and in-depth interviews with leading researchers, pioneers and feminist scientists in the field, her analysis engages with key theoretical approaches in gender studies of science. Analyzing the researchers’ scientific interests, theoretical frameworks, specific study animals, technological innovations, methodologies and sometimes feminist insights, reveals how these have shaped conclusions drawn about sex. Thereby, The Female Turn shows how certain researchers gained knowledge about active females whereas others missed, ignored or delayed it – that is, how ignorance was produced.

While it is widely acknowledged that Darwin’s descriptions of females were gender-biased, gender bias in modern sexual selection research is less recognized. This Perspective highlights that sexual selection theory and research are still male-centered and suggest strategies for alleviating biases in this field and beyond. While it is widely acknowledged that Darwin’s descriptions of females were gender-biased, gender bias in current sexual selection research is less recognized. An examination of the history of sexual selection research shows prevalent male precedence-that research starts with male-centered investigations or explanations and thereafter includes female-centered equivalents. In comparison, the incidence of female precedence is low. Furthermore, a comparison between the volume of publications focusing on sexual selection in males versus in females shows that the former far outnumber the latter. This bias is not only a historical pattern; sexual selection theory and research are still male-centered-due to conspicuous traits, practical obstacles, and continued gender bias. Even the way sexual selection is commonly defined contributes to this bias. This history provides an illustrative example by which we can learn to recognize biases and identify gaps in knowledge. I conclude with a call for the scientific community to interrogate its own biases and suggest strategies for alleviating biases in this field and beyond.

“Sex roles” are intuitively associated to stereotypic female and male sexual strategies and in biology, the term “sex role” often relates to mating competition, mate choice or parental care. “Sex role reversals” imply that the usual typological pattern for a population or species is deviates from a norm, and the meaning of “sex role reversal” thus varies depending upon whatever is the usual pattern of sex-typical behavior in a given taxon. We identify several problems with the current use of the “sex role” concept. (1) It is typological and reflects stereotypic expectations of the sexes. (2) The term “sex role” parses continuous variation into only two categories, often obscuring overlap, between the sexes in behavior and morphology, and variability in relation to ecological circumstances. (3) Common generalizations such as “sex role as seen in nature” mask variation upon which selection may act. (4) The general meaning of “sex roles” in society (i.e. “socially and culturally defined prescriptions and beliefs about the behavior and emotions of men and women”) is contrary to biological “sex role” concepts, so that confusing the two obscure science communication in society. We end by questioning the validity of the “sex role” concept in evolutionary biology and recommend replacing the term “sex role” with operational descriptions.

The diversity, variability, and apparent rapid evolution of animal genitalia are a vivid focus of research in evolutionary biology, and studies exploring genitalia have dramatically increased over the past decade. These studies, however, exhibit a strong male bias, which has worsened since 2000, despite the fact that this bias has been explicitly pointed out in the past. Early critics argued that previous investigators too often considered only males and their genitalia, while overlooking female genitalia or physiology. Our analysis of the literature shows that overall this male bias has worsened with time. The degree of bias is not consistent between subdisciplines: studies of the lock-and-key hypothesis have been the most male focused, while studies of cryptic female choice usually consider both sexes. The degree of bias also differed across taxonomic groups, but did not associate with the ease of study of male and female genital characteristics. We argue that the persisting male bias in this field cannot solely be explained by anatomical sex differences influencing accessibility. Rather the bias reflects enduring assumptions about the dominant role of males in sex, and invariant female genitalia. New research highlights how rapidly female genital traits can evolve, and how complex coevolutionary dynamics between males and females can shape genital structures. We argue that understanding genital evolution is hampered by an outdated single-sex bias.

Mate choice hypotheses usually focus on trait variation of chosen individuals. Recently, mate choice studies have increasingly attended to the environmental circumstances affecting variation in choosers’ behavior and choosers’ traits. We reviewed the literature on phenotypic plasticity in mate choice with the goal of exploring whether phenotypic plasticity can be interpreted as individual flexibility in the context of the switch point theorem, SPT (Gowaty and Hubbell ). We found >3000 studies; 198 were empirical studies of within-sex phenotypic plasticity, and sixteen showed no evidence of mate choice plasticity. Most studies reported changes from choosy to indiscriminate behavior of subjects. Investigators attributed changes to one or more causes including operational sex ratio, adult sex ratio, potential reproductive rate, predation risk, disease risk, chooser’s mating experience, chooser’s age, chooser’s condition, or chooser’s resources. The studies together indicate that choosiness of potential mates is environmentally and socially labile, that is, induced - not fixed - in the choosy sex with results consistent with choosers’ intrinsic characteristics or their ecological circumstances mattering more to mate choice than the traits of potential mates. We show that plasticity-associated variables factor into the simpler SPT variables. We propose that it is time to complete the move from questions about within-sex plasticity in the choosy sex to between- and within-individual flexibility in reproductive decision-making of both sexes simultaneously. Currently, unanswered empirical questions are about the force of alternative constraints and opportunities as inducers of individual flexibility in reproductive decision-making, and the ecological, social, and developmental sources of similarities and differences between individuals. To make progress, we need studies (1) of simultaneous and symmetric attention to individual mate preferences and subsequent behavior in both sexes, (2) controlled for within-individual variation in choice behavior as demography changes, and which (3) report effects on fitness from movement of individual’s switch points.

Evolution of male care is still poorly understood. Using phylogenetically matched-pairs comparisons we tested for effects of territoriality and mating system on male care evolution in fish. All origins of male care were found in pair-spawning species (with or without additional males such as sneakers) and none were found in group-spawning species. However, excluding group spawners, male care originated equally often in pair-spawning species with additional males as in strict pair-spawning species. Evolution of male care was also significantly related to territoriality. Yet, most pair-spawning taxa with male care are also territorial, making their relative influence difficult to separate. Furthermore, territoriality also occurs in group-spawning species. Hence, territoriality is not sufficient for male care to evolve. Rather, we argue that it is the combination of territoriality and pair spawning with sequential polygyny that favours the evolution of male care, and we discuss our results in relation to paternity assurance and sexual selection.

It is common to refer to all sorts of clear-cut differences between the sexes as something that is biologically almost inevitable. Although this does not reflect the status of evolutionary theory on sex determination and sexual dimorphism, it is probably a common view among evolutionary biologists as well, because of the impact of sexual selection theory. To get away from thinking about biological sex and traits associated with a particular sex as something static, it should be recognized that in an evolutionary perspective sex can be viewed as a reaction norm, with sex attributes being phenotypically plastic. Sex determination itself is fundamentally plastic, even when it is termed “genetic”. The phenotypic expression of traits that are statistically associated with a particular sex always has a plastic component. This plasticity allows for much more variation in the expression of traits according to sex and more overlap between the sexes than is typically acknowledged. Here we review the variation and frequency of evolutionary changes in sex, sex determination and sex roles and conclude that sex in an evolutionary time-frame is extremely variable. We draw on recent findings in sex determination mechanisms, empirical findings of morphology and behaviour as well as genetic and developmental models to explore the concept of sex as a reaction norm. From this point of view, sexual differences are not expected to generally fall into neat, discrete, pre-determined classes. It is important to acknowledge this variability in order to increase objectivity in evolutionary research.

The callitrichines are known for twinning and for a communal rearing system in which all or most group members help care for the offspring. The origin of twinning has been the subject of much speculation. In this study predictions from earlier hypotheses are tested on the basis of two alternative phylogenetic trees. From this analysis we infer that helping behavior and male care preceded the origin of twinning, and that these traits did not coevolve with, but might have been important prerequisites for twinning in callitrichines. Small body size does not necessarily result in twinning, although it might still have been a prerequisite for its evolution. Gum feeding was an ecological change which evolved along with twinning. If nutrition was a limiting factor in the number of offspring produced, then the use of a new feeding resource could have been crucial for the origin of twinning in callitrichines. According to one of the two alternative solutions inferred by the total evidence tree, and in accordance with the morphological tree, semi-annual breeding appears in the marmosets together with specialization in gum feeding. The fact that gums are available for these monkeys all year may have facilitated semiannual breeding. We suggest that the exploitation of gums as a feeding resource could have been the decisive factor in the increase of the reproductive rate by twinning and by semi-annual breeding.

Filosofer såväl som forskare har länge hävdat att förundran är en nyckel till elevers intresse och engagemang i skolans NO-undervisning. Trots detta finns det i nuläget mycket få empiriska studier som beskriver lärares arbete med att ge plats för förundran i skolans NO-undervisning.

Syftet med denna studie är att undersöka hur elevers förundran kan studeras i klassrumssituationer samt om, och hur, elevers uttryck för förundran kan kopplas till deras meningsskapande om ett planerat lärandemål.

I studien har forskare och en NO-lärare (årskurs 7) samarbetat för att utforma evolutionsundervisning med plats för elevers förundran. Följande forskningsfrågor fokuseras:

1. På vilka sätt kan lärare ge plats för förundran i samband med evolutionsundervisning?
2. Hur påverkar undervisning, med plats för förundran, elevers möjligheter för meningsskapande om evolutionära processer och begrepp kopplade till dessa?

Empirin består av 45 individuella skriftliga elevreflektioner och transkriberade ljudinspelningar från 6 parvisa elevintervjuer. Elevernas reflektioner analyserades i två steg. Steg ett fokuserade på hur eleverna uttryckte förundran i relation till frågan Vad brukar du förundras över? Steg två på vad de förundrats över i evolutionsundervisningen. Elevintervjuerna analyserades med fokus på elevernas meningsskapande om evolutionära processer.

Resultaten visar att eleverna ger uttryck för förundran kopplat till variation, mångfald, evolutionära tidsaspekter och samspel mellan organismer och livsmiljö. Elevernas förundran skiljer sig kvalitativt inom ett spänningsfält mellan nyfikenhetsbaserad förundran och kontemplativ förundran. Samtidigt visar elevintervjuerna att eleverna fortfarande, efter sex veckor av undervisning, kämpar med att integrera vetenskapliga begrepp från evolutionsteorin med sitt eget meningsskapande om processerna.

We examined the longitudinal relationship between IQ and fine particulate matter (\2.5lm aerodynamic diameters; PM2.5) exposure in urban-dwelling children, using prospective longitudinal data from the USC Twin Study of Risk Factors for Antisocial Behavior (RFAB; Baker et al. 2013). Residential addresses were collected via selfreports. Verbal and Performance IQ during childhood (age 9–10) and young adulthood (age 19–20) were evaluated by the Wechsler Abbreviated Intelligence Scale (Wechsler, 1999) using four subtests: VIQ=Vocabulary Similarities; PIQ=Block Design Matrices. Based on residential addresses and spatiotemporal generalized additive model of local monitoring data for PM2.5, we estimated 1-year average exposure before each assessment. A three-level mixed effects model regressing IQ scores at each assessment on time-varying air pollution exposures, accounting for both within-family (random intercepts) and within-individual (random slopes) was used. PM2.5 exposure had significant adverse effects on PIQ (95 % CI of b:-7.29 to-1.01, p\.05) but not VIQ (95 % CI of b:-4.50 to-1.96). Adverse effects of PM2.5 exposure remained significant after adjusting for age, family SES, sex, race/ethnicity, parental cognitive abilities, neighborhood SES, neighborhood quality and neighborhood greenness; the association was still significant after further adjusting for traffic distance (300 m), temperature, humidity and annual NOx. PM2.5 exposure confers stronger adverse effects on PIQ in low SES families, males, and during pre-adolescence. Our findings reveal social disparities and sexual dimorphism in the adverse PM2.5 exposure effects on PIQ. Baker, L., Tuvblad, C., Wang, P., Gomez, K., Bezdjian, S., Niv, S., & Raine, A. (2013). The Southern California Twin Register at the University of Southern California: III. Twin Research and Human Genetics, 16(1), 336–343; Wechsler, D. (1999). Wechsler Abbreviated Scale of Intelligence (WASI). San Antonio, Texas: Harcourt Assessment.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used pharmaceuticals to treat pain, fever and inflammation. NSAIDs are also known to have many side effects including adverse effects on reproduction in both humans and animals. As NSAIDs usage is not regulated they are frequently detected at high concentrations in the environment. In order to understand the effect of NSAIDs on zebrafish sex differentiation, we used seven different NSAIDs which were either Cox-1 selective, Cox-1 biased, non-selective or COX-2 selective. We show that at higher concentration, NSAIDs are toxic to zebrafish embryo as they lead to mortality and hatching delay. Gene expression analysis following short term exposure of NSAIDs led to downregulation of female specific genes including zp2, vtg2 foxl2 and wnt4. Long term exposure of larvae to environmentally relevant concentrations of Cox-2 selective and non-selective NSAIDs resulted in male-biased sex ratio which confirmed the qRT-PCR analysis. However, the Cox-1 selective acetylsalicylic acid and the Cox-1 biased ketoprofen did not alter sex ratio. The observed male-biased sex ratio could also be due to induction of apoptosis process as the genes including p21 and casp8 were significantly upregulated following exposure to the Cox-2 selective and the non-selective NSAIDs. The present study indicates that NSAIDs alter sex differentiation in zebrafish, primarily through inhibition of Cox-2. This study clearly demonstrates that the use of NSAIDs and their release into the aquatic environment should be carefully monitored to avoid adverse effects to the aquatic organisms. 

Startle reflex and affect-modified startle reflex are used as indicators of defensive reactivity and emotional processing, respectively. The present study investigated the heritability of both the startle blink reflex and affect modification of this reflex in a community sample of 772 twins ages 14–15 years old. Subjects were shown affective picture slides falling in three valence categories: negative, positive and neutral; crossed with two arousal categories: high arousal and low arousal. Some of these slides were accompanied with a loud startling noise. Results suggestedsex differences in meanlevels of startle reflex as well as in proportions of variance explained by genetic and environmental factors. Females had higher mean startle blink amplitudes for each valence-arousal slide category, indicating greater baseline defensive reactivity compared to males. Startle blink reflex in males was significantly heritable (49%), whereas in females, variance was explained primarily by shared environmental factors (53%) and non-shared environmental factors (41%). Heritability of affect modified startle (AMS) was found to be negligible in both males and females. These results suggest sex differences in the etiology of startle reactivity, while questioning the utility of the startle paradigm for understanding the genetic basis of emotional processing.

This paper examines why violence in films is so widespread and popular. I use an evolutionary biological perspective, that has not previously been used in film research as much. Instead, the film research and other studies on human behavior usually originate from a social constructionist perspective. The essay is a "research review", which means that I have not made a classic analysis of a cinematic work or empirical data, but have collected a large amount of research from other scientists. To be able to answer my question, I had to do research in human evolution, audio visual perception and violence in film. The most important book for the essay came to be Torben Grodals Embodied Visions. The main question in my research question was: What factors are in accordance with previous research behind the popularity of graphic violence? Answer: 1. Film is designed to affect us, activating emotions. 2. what affects us the most is images that reminds us of deeply rooted mechanisms inside us. 3. of evolutionary reasons, violence and aggression are among these deep-rooted mechanisms.

Chlamydia trachomatis is the world's most prevalent bacterial sexually transmitted infection and leading infectious cause of blindness, yet it is one of the least understood human pathogens, in part due to the difficulties of in vitro culturing and the lack of available tools for genetic manipulation. Genome sequencing has reinvigorated this field, shedding light on the contemporary history of this pathogen. Here, we analyze 563 full genomes, 455 of which are novel, to show that the history of the species comprises two phases, and conclude that the currently circulating lineages are the result of evolution in different genomic ecotypes. Temporal analysis indicates these lineages have recently expanded in the space of thousands of years, rather than the millions of years as previously thought, a finding that dramatically changes our understanding of this pathogen's history. Finally, at a time when almost every pathogen is becoming increasingly resistant to antimicrobials, we show that there is no evidence of circulating genomic resistance in C. trachomatis.

Height variation is known to be determined by both genetic and environmental factors, but a systematic description of how their influences differ by sex, age and global regions is lacking. We conducted an individual-based pooled analysis of 45 twin cohorts from 20 countries, including 180,520 paired measurements at ages 1-19 years. The proportion of height variation explained by shared environmental factors was greatest in early childhood, but these effects remained present until early adulthood. Accordingly, the relative genetic contribution increased with age and was greatest in adolescence (up to 0.83 in boys and 0.76 in girls). Comparing geographic-cultural regions (Europe, North-America and Australia, and East-Asia), genetic variance was greatest in North-America and Australia and lowest in East-Asia, but the relative proportion of genetic variation was roughly similar across these regions. Our findings provide further insights into height variation during childhood and adolescence in populations representing different ethnicities and exposed to different environments.

Human height variation is determined by genetic and environmental factors, but it remains unclear whether their influences differ across birth-year cohorts. We conducted an individual-based pooled analysis of 40 twin cohorts including 143,390 complete twin pairs born 1886-1994. Although genetic variance showed a generally increasing trend across the birth-year cohorts, heritability estimates (0.69-0.84 in men and 0.53-0.78 in women) did not present any clear pattern of secular changes. Comparing geographic-cultural regions (Europe, North America and Australia, and East Asia), total height variance was greatest in North America and Australia and lowest in East Asia, but no clear pattern in the heritability estimates across the birth-year cohorts emerged. Our findings do not support the hypothesis that heritability of height is lower in populations with low living standards than in affluent populations, nor that heritability of height will increase within a population as living standards improve.

Bacterial speciation is a fundamental evolutionary process characterized by diverging genotypic and phenotypic properties. However, the selective forces that affect genetic adaptations and how they relate to the biological changes that underpin the formation of a new bacterial species remain poorly understood. Here, we show that the spore-forming, healthcare-associated enteropathogen Clostridium difficile is actively undergoing speciation. Through large-scale genomic analysis of 906 strains, we demonstrate that the ongoing speciation process is linked to positive selection on core genes in the newly forming species that are involved in sporulation and the metabolism of simple dietary sugars. Functional validation shows that the new C. difficile produces spores that are more resistant and have increased sporulation and host colonization capacity when glucose or fructose is available for metabolism. Thus, we report the formation of an emerging C. difficile species, selected for metabolizing simple dietary sugars and producing high levels of resistant spores, that is adapted for healthcare-mediated transmission.

The capacity to learn and reproduce vocal sounds has evolved in phylogenetically distant tetrapod lineages. Vocal learners in all these lineages express similar neural circuitry and genetic factors when perceiving, processing, and reproducing vocalization, suggesting that brain pathways for vocal learning evolved within strong constraints from a common ancestor, potentially fish. We hypothesize that the auditory-motor circuits and genes involved in entrainment have their origins in fish schooling behavior and respiratory-motor coupling. In this acoustic advantages hypothesis, aural costs and benefits played a key role in shaping a wide variety of traits, which could readily be exapted for entrainment and vocal learning, including social grouping, group movement, and respiratory-motor coupling. Specifically, incidental sounds of locomotion and respiration (ISLR) may have reinforced synchronization by communicating important spatial and temporal information between school-members and extending windows of silence to improve situational awareness. This process would be mutually reinforcing. Neurons in the telencephalon, which were initially involved in linking ISLR with forelimbs, could have switched functions to serve vocal machinery (e.g. mouth, beak, tongue, larynx, syrinx). While previous vocal learning hypotheses invoke transmission of neurons from visual tasks (gestures) to the auditory channel, this hypothesis involves the auditory channel from the onset. Acoustic benefits of locomotor-respiratory coordination in fish may have selected for genetic factors and brain circuitry capable of synchronizing respiratory and limb movements, predisposing tetrapod lines to synchronized movement, vocalization, and vocal learning. We discuss how the capacity to entrain is manifest in fish, amphibians, birds, and mammals, and propose predictions to test our acoustic advantages hypothesis.

Intellectual disability (ID) occurs in almost 3% of newborns. Despite substantial research, a fundamental question about its origin and links to intelligence (IQ) still remains. ID has been shown to be inherited and has been accepted as the extreme low of the normal IQ distribution. However, ID displays a complex pattern of inheritance. Previously, noninherited rare mutations were shown to contribute to severe ID risk in individual families, but in the majority of cases causes remain unknown. Common variants associated with ID risk in the population have not been systematically established. Here we evaluate the hypothesis, originally proposed almost 1 century ago, that most ID is caused by the same genetic and environmental influences responsible for the normal distribution of IQ, but that severe ID is not. We studied more than 1,000,000 sibling pairs and 9,000 twin pairs assessed for IQ and for the presence of ID. We evaluated whether genetic and environmental influences at the extremes of the distribution are different from those operating in the normal range. Here we show that factors influencing mild ID (lowest 3% of IQ distribution) were similar to those influencing IQ in the normal range. In contrast, the factors influencing severe ID (lowest 0.5% of IQ distribution) differ from those influencing mild ID or IQ scores in the normal range. Taken together, our results suggest that most severe ID is a distinct condition, qualitatively different from the preponderance of ID, which, in turn, represents the low extreme of the normal distribution of intelligence.

BACKGROUND: Although generally known as a human commensal, Staphylococcus epidermidis is also an opportunistic pathogen that can cause nosocomial infections related to foreign body materials and immunocompromized patients. Infections are often caused by multidrug-resistant (MDR) lineages that are difficult and costly to treat, and can have a major adverse impact on patients' quality of life. Heterogeneity is a common phenomenon in both carriage and infection, but present methodology for detection of this is laborious or expensive. In this study, we present a culture-independent method, labelled Epidome, based on an amplicon sequencing-approach to deliver information beyond species level on primary samples and to elucidate clonality, population structure and temporal stability or niche selection of S. epidermidis communities.

RESULTS: Based on an assessment of > 800 genes from the S. epidermidis core genome, we identified genes with variable regions, which in combination facilitated the differentiation of phylogenetic clusters observed in silico, and allowed classification down to lineage level. A duplex PCR, combined with an amplicon sequencing protocol, and a downstream analysis pipeline were designed to provide subspecies information from primary samples. Additionally, a probe-based qPCR was designed to provide valuable absolute abundance quantification of S. epidermidis. The approach was validated on isolates representing skin commensals and on genomic mock communities with a sensitivity of < 10 copies/μL. The method was furthermore applied to a sample set of primary skin and nasal samples, revealing a high degree of heterogeneity in the S. epidermidis populations. Additionally, the qPCR showed a high degree of variation in absolute abundance of S. epidermidis.

CONCLUSIONS: The Epidome method is designed for use on primary samples to obtain important information on S. epidermidis abundance and diversity beyond species-level to answer questions regarding the emergence and dissemination of nosocomial lineages, investigating clonality of S. epidermidis communities, population dynamics, and niche selection. Our targeted-sequencing method allows rapid differentiation and identification of clinically important nosocomial lineages in low-biomass samples such as skin samples.

Learning about evolution can be challenging for students, as a full understanding may require them to see the world in new ways, to master a disciplinary language and to understand complex processes. Drawing on a long line of theoretically grounded arguments of philosophers and researchers for including wonder in science teaching, we report on the results of an empirical study with the primary aim of investigating the role of wonder in students’ learning about evolution. The study was carried out through a formative intervention in which two researchers in science education collaborated with a seventh-grade teacher. Over a period of six weeks, 45 students participated in lessons and workshops aimed at eliciting a sense of wonder in relation to concepts that are known to impact the learning of evolution. We incorporated four ‘triggers’ to elicit students’ wonder in the science class: aesthetic experiences, defiance of expectations, agency and awareness of a mystery within the ordinary. Logbook entries and interviews with student pairs provided empirical material for a qualitative analysis of the role of wonder in the students’ meaning-making about, learning of and engagement in evolution. The results show that it is possible to design science teaching that triggers students’ wonder in relation to an intended learning object. The results also reveal that the participating students described their sense of wonder in qualitatively different ways and that they still struggled to make sense of the concept of evolution after six weeks of teaching.

Both long-term environmental changes such as those driven by the glacial cycles and more recent anthropogenic impacts have had major effects on the past demography in wild organisms. Within species, these changes are reflected in the amount and distribution of neutral genetic variation. In this thesis, mitochondrial and microsatellite DNA was analysed to investigate how environmental and anthropogenic factors have affected genetic diversity and structure in four ecologically different animal species. Paper I describes the post-glacial recolonisation history of the speckled-wood butterfly (Pararge aegeria) in Northern Europe. A decrease in genetic diversity with latitude and a marked population structure were uncovered, consistent with a hypothesis of repeated founder events during the postglacial recolonisation. Moreover, Approximate Bayesian Computation analyses indicate that the univoltine populations in Scandinavia and Finland originate from recolonisations along two routes, one on each side of the Baltic. Paper II aimed to investigate how past sea-level rises affected the population history of the convict surgeonfish (Acanthurus triostegus) in the Indo-Pacific. Assessment of the species’ demographic history suggested a population expansion that occurred approximately at the end of the last glaciation. Moreover, the results demonstrated an overall lack of phylogeographic structure, probably due to the high dispersal rates associated with the species’ pelagic larval stage. Populations at the species’ eastern range margin were significantly differentiated from other populations, which likely is a consequence of their geographic isolation. In Paper III, we assessed the effect of human impact on the genetic variation of European moose (Alces alces) in Sweden. Genetic analyses revealed a spatial structure with two genetic clusters, one in northern and one in southern Sweden, which were separated by a narrow transition zone. Moreover, demographic inference suggested a recent population bottleneck. The inferred timing of this bottleneck coincided with a known reduction in population size in the 19^th and early 20^th century due to high hunting pressure. In Paper IV, we examined the effect of an indirect but well-described human impact, via environmental toxic chemicals (PCBs), on the genetic variation of Eurasian otters (Lutra lutra) in Sweden. Genetic clustering assignment revealed differentiation between otters in northern and southern Sweden, but also in the Stockholm region. ABC analyses indicated a decrease in effective population size in both northern and southern Sweden. Moreover, comparative analyses of historical and contemporary samples demonstrated a more severe decline in genetic diversity in southern Sweden compared to northern Sweden, in agreement with the levels of PCBs found.

The Eurasian otter (Lutra lutra) population in Sweden went through a drastic decline in population size between the 1950s and 1980s, caused mostly by anthropogenic factors such as high hunting pressure and the introduction of environmental toxic chemicals into the otter’s habitats. However, after the bans of PCBs and DDT in the 1970s, the population began to recover in the 1990s. This study compares microsatellite data across twelve loci from historical and contemporary otter samples to investigate whether there has been a change in population structure and genetic diversity across time in various locations throughout Sweden. The results suggest that otters in the south were more severely affected by the bottleneck, demonstrated by a decline in genetic diversity and a shift in genetic composition. In contrast, the genetic composition in otters from northern Sweden remained mostly unchanged, both in terms of population structure and diversity. This suggests that the decline was not uniform across the country. Moreover, our analyses of historical samples provide an overview of the level of genetic variation and population structure that existed prior to the bottleneck, which may be helpful for the future management and conservation of the species.

The post-glacial recolonisation of northern Europe has left distinct signatures in the genomes of many organisms, both due to random demographic processes and divergent natural selection. However, information on differences in genetic variation in conjunction with patterns of local adaptations along latitudinal gradients is often lacking. In this study, we examine genetic diversity and population structure in the speckled wood butterfly Pararge aegeria in northern Europe to investigate the species post-glacial recolonisation history and discuss how this may have affected its life-history evolution. We collected 209 samples and analysed genetic variation in nine microsatellite loci. The results demonstrated a more pronounced population structure in northern Europe compared with populations further south, as well as an overall decrease in genetic diversity with latitude, likely due to founder effects during the recolonisation process. Coalescent simulations coupled with approximate Bayesian computation suggested that central Scandinavia was colonised from the south, rather than from the east. In contrast to further south, populations at the northern range margin are univoltine expressing only one generation per year. This suggests either that univoltinism evolved independently on each side of the Baltic Sea, or that bivoltinism evolved in the south after northern Europe was recolonised.

Due to the controversy surrounding incipient avian parental care, ancestral parental care systems were reconstructed in a phylogeny including major extant amniote lineages. Using two different resolutions for the basal avian branches, transitions between the states no care, female care, biparental care and male care were inferred for the most basal branches of the tree. Uniparental female care was inferred for the lineage to birds and crocodiles. Using a phylogeny where ratites and tinamous branch off early and an ordered character-state assumption, a transition to biparental care was inferred for the ancestor of birds. This ancestor could be any organism along the lineage leading from the crocodile-bird split up to modem birds, not necessarily the original bird. We discuss the support for alternative avian phylogenies and the homology in parental care between crocodiles and birds. We suggest that the phylogenetic pattern should be used as a starting point for a more detailed analysis of parental care systems in birds and their relatives.

This paper will broadly review the currently available twin and adoption data on antisocial behaviour (AB). It is argued that quantitative genetic research can make a significant contribution to further the understanding of how AB develops. Genetically informative study designs are particularly useful for investigating several important questions such as whether: the heritability estimates vary as a function of assessment method or gender; the relative importance of genetic and environmental influences varies for different types of AB; the environmental risk factors are truly environmental; and genetic vulnerability influences susceptibility to environmental risk. While the current data are not yet directly translatable for prevention and treatment programmes, quantitative genetic research has concrete translational potential. Quantitative genetic research can supplement neuroscience research in informing about different subtypes of AB, such as AB coupled with callous-unemotional traits. Quantitative genetic research is also important in advancing the understanding of the mechanisms by which environmental risk operates.

Mycorrhizal associations are widespread in high-latitude ecosystems and are potentially of great importance for global carbon dynamics. Although large herbivores play a key part in shaping subarctic plant communities, their impact on mycorrhizal dynamics is largely unknown. We measured extramatrical mycelial (EMM) biomass during one growing season in 16-year-old herbivore exclosures and unenclosed control plots (ambient), at three mountain birch forests and two shrub heath sites, in the Scandes forest-tundra ecotone. We also used high-throughput amplicon sequencing for taxonomic identification to investigate differences in fungal species composition. At the birch forest sites, EMM biomass was significantly higher in exclosures (1.36 +/- 0.43g C/m(2)) than in ambient conditions (0.66 +/- 0.17g C/m(2)) and was positively influenced by soil thawing degree-days. At the shrub heath sites, there was no significant effect on EMM biomass (exclosures: 0.72 +/- 0.09g C/m(2); ambient plots: 1.43 +/- 0.94). However, EMM biomass was negatively related to Betula nana abundance, which was greater in exclosures, suggesting that grazing affected EMM biomass positively. We found no significant treatment effects on fungal diversity but the most abundant ectomycorrhizal lineage/cortinarius, showed a near-significant positive effect of herbivore exclusion (p=.08), indicating that herbivory also affects fungal community composition. These results suggest that herbivory can influence fungal biomass in highly context-dependent ways in subarctic ecosystems. Considering the importance of root-associated fungi for ecosystem carbon balance, these findings could have far-reaching implications.

The Scandinavian brown bear went through a major decline in population size approximately 100 years ago, due to intense hunting. After being protected, the population subsequently recovered and today numbers in the thousands. The genetic diversity in the contemporary population has been investigated in considerable detail, and it has been shown that the population consists of several subpopulations that display relatively high levels of genetic variation. However, previous studies have been unable to resolve the degree to which the demographic bottleneck impacted the contemporary genetic structure and diversity. In this study, we used mitochondrial and microsatellite DNA markers from pre- and postbottleneck Scandinavian brown bear samples to investigate the effect of the bottleneck. Simulation and multivariate analysis suggested the same genetic structure for the historical and modern samples, which are clustered into three subpopulations in southern, central and northern Scandinavia. However, the southern subpopulation appears to have gone through a marked change in allele frequencies. When comparing the mitochondrial DNA diversity in the whole population, we found a major decline in haplotype numbers across the bottleneck. However, the loss of autosomal genetic diversity was less pronounced, although a significant decline in allelic richness was observed in the southern subpopulation. Approximate Bayesian computations provided clear support for a decline in effective population size during the bottleneck, in both the southern and northern subpopulations. These results have implications for the future management of the Scandinavian brown bear because they indicate a recent loss in genetic diversity and also that the current genetic structure may have been caused by historical ecological processes rather than recent anthropogenic persecution.