| 1. |
- Lindsay, Willow R, et al.
(författare)
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Endless forms of sexual selection
- 2024
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The field of sexual selection has burgeoned with research into trait evolution in the context of ecology, sociality, phylogeny, natural selection, and sexual conflict. This paper is the product of a “stock-taking” workshop; our aim is to stimulate discussion, not to provide an exhaustive review. We identify outstanding questions organized into four thematic sections.1) Evolution of mate choice and mating systems. Variation in mate quality can generate mating competition and choice in either sex with implications for the evolution of mating systems. Limitations on mate choice may dictate the importance of direct vs. indirect benefits in mating decisions and consequently, mating systems. Specifically, polyandry evolves in response to the strength of pre- vs. post-copulatory selection. The evolution of polyandry may be related to diversity of pathogens and Major Histocompatibility Complex (MHC) genes. MHC genes are also potential cues of kinship in avoidance of inbreeding. The balance between inbreeding avoidance and inclusive fitness in mating decisions deserves greater attention.2) Sender and receiver mechanisms shaping signal design. Mediation of honest signal content likely depends on integration of temporally variable social and physiological costs that are a challenge to measure. The neuroethology of sensory and cognitive receiver biases is the main key to signal form and the ‘aesthetic sense’ proposed by Darwin. Since a receiver bias is sufficient to both start and drive ornament or armament exaggeration, without a genetically correlated or even coevolving receiver, this may be the appropriate ‘null model’ of sexual selection.3) Genetic architecture of sexual selection. Despite advances in modern molecular techniques, the number and identity of genes underlying performance remain largely unknown. A combination of genomic techniques and long-term field studies that reveal ecological correlates of reproductive success is warranted. In-depth investigations into the genetic basis of sexual dimorphism will reveal constraints and trajectories of sexually selected trait evolution.4) Sexual selection and conflict as drivers of speciation. Population divergence and speciation is often driven by an interplay between sexual and natural selection. To what extent sexual selection promotes or counteracts population divergence may differ depending on the genetic architecture of traits as well as covariance between mating competition and local adaptation, if traits have multiple functions and if sensory systems used in mate choice are locally adapted. Also, post-copulatory processes, e.g. selection against heterospecific sperm, may influence the importance of sexual selection. Sexual conflict can shape speciation processes, since mate choice selection on females can restrict gene flow whereas selection on males is permissive.We propose that efforts to resolve these four themes can catalyze conceptual progress in the field of sexual selection.
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| 2. |
- Svensson, Ola, 1971-, et al.
(författare)
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Data from: Sympatry and parapatry among rocky reef cichlids of Lake Victoria explained by female mating preferences [Dataset]
- 2024
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Annan publikationabstract
- Work on the Lake Victoria cichlids Pundamilia nyererei (red dorsum males, deeper water), Pundamilia pundamilia (blue males, shallower water) and related species pairs has provided insights into processes of speciation. Here, we investigate female mating behaviour of five Pundamilia species and four of their F1-hybrids through mate choice trials and paternity testing. We discuss the results in the context of the geography of speciation and coexistence. Complete assortative mating was observed among all sympatric species. Parapatric species with similar depth habitat distributions interbred whereas other parapatric and allopatric species showed complete assortative mating. F1-hybrids mated exclusively with species accepted by females of the parental species. Although consistent with reinforcement in sympatry, a closer look at our results suggests otherwise and it is more likely that pre-existing female preferences influence which taxa can co-exist in sympatry. Regardless of the mechanism, mating preferences may influence species distribution in potentially hybridizing taxa, such as in the adaptive radiations of cichlid fish. We suggest that this at least partly explains why some species fail to establish breeding populations in locations where they are occasionally recorded. Our result support the notion that mating preferences of potentially cross-breeding species ought to be included in coexistence theory.
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| 3. |
- Andersson, Marica, et al.
(författare)
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Increased noise levels cause behavioural and distributional changes in Atlantic cod and saithe in a large public aquarium—A case study
- 2023
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Ingår i: Aquaculture, Fish and Fisheries. - : John Wiley & Sons. - 2693-8847.
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Investigating the effects of underwater noise on aquatic animals is a research field that is receiving rapidly increasing attention. Despite this, surprisingly few studies have addressed the potential impacts of noise in a marine animal husbandry setting. In this regard, the behaviour of fish in public aquariums can be used as an indicator of well-being, and noise is known to cause behavioural changes. This case study investigates the behaviour of cod (Gadus morhua) and saithe (Pollachius virens) in a large public aquarium when exposed to increased noise levels originating from an aquarium renovation carried out by construction divers. Swimming behaviour, group formation and vertical distribution, along with yawning and scratching frequencies of the fish, were analysed from video recordings made before, during and after the exposure to increased noise levels. The same parameters were also analysed to evaluate potential effects of the presence of divers when not making renovation noise, compared to fish behaviour prior to the renovation. There was a slight change in the depth distribution of both species and a decrease in the number of scratches in cod due to the presence of divers that were not making renovation noise. In the presence of construction noises in the tank, however, both cod and saithe showed a wider array of behavioural changes, including increased swimming speed, changes in depth distribution and increased yawning frequencies. The results from this case study demonstrate that an underwater renovation with increased noise levels impacts fish behaviour and suggests that underwater noise should be considered during the management of aquatic environments, including public aquaria.
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| 4. |
- Balducci, Francesco, et al.
(författare)
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“How Far Is the Closest Bus Stop?” : An Evaluation of Self-Reported versus GIS-Computed Distance to the Bus among Older People and Factors Influencing Their Perception of Distance
- 2023
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Ingår i: Geomatics. - 2673-7418. ; 3:4, s. 580-596
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Tidskriftsartikel (refereegranskat)abstract
- Previous research showed that living closer to bus stops could be a factor in promoting a healthy and active lifestyle. However, most of the studies relied on self-reported measures of distance, which might be affected by several confounders. In this study, self-reported distances among study participants were compared to actual ones, computed by the use of GIS (Geographic Information System) technology and routing algorithms. We tested whether distance to the bus stop is associated with health and socioeconomic conditions of the respondents, using data among 2398 older people (75–90 years) in three cities in Sweden. We found that several variables including older age, female gender, living alone, and worse health status are associated with an over-estimation of bus stop distance. People who use public transport daily or several times a week and are satisfied with the walking environment in the neighbourhood tend to underestimate bus stop distances. Evidence based on self-reported measures only should be treated cautiously. Considering the limitations still present in open-data-based routing algorithms, the best indication is to combine the subjective with the objective measure of distance. Having the possibility to combine the two measures appears as a sound strategy to overcome the limitations associated with each single measure.
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| 5. |
- Berg, Joel, 1984-
(författare)
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Fullmakten och dess uppkomst : Särskilt om huvudmannens viljeförklaring och tredje mans befogade tillit
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In Sweden, opinions have long been divided on the meaning of the agency concept of authority and its basis. Due to a number of judgments from the Swedish Supreme Court, the discussion has been given renewed relevance. The dissertation investigates the question of the origin of authority. By using a legal dogmatic method, relevant sources are identified and analyzed in order to determine the content of current law.The dissertation first describes the development of authority in Swedish law and the purpose and function of authority rules. For there to be an act of authorization, it is required that the person who performs a legal act does so in the name of another. However, the exact meaning of acting in the name of another has proved to be far from obvious. The concept is central to the act of authorization, which is why it is also defined within the framework of this dissertation.The concept of declaration of intent, which plays a central role in the creation of authority, is also discussed. This is because there are divided opinions as to whether there are any subjective requirements on the principal or recipient for a declaration of intent to be considered to exist.Finally, the grounds for authority that have been identified in the dissertation are presented by analyzing the potential grounds identified within the framework of the dissertation.
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| 6. |
- Green, Leon, et al.
(författare)
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Invader at the edge - Genomic origins and physiological differences of round gobies across a steep urban salinity gradient
- 2023
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Ingår i: Evolutionary Applications. - : Wiley. - 1752-4571. ; 16:2, s. 321-37
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Tidskriftsartikel (refereegranskat)abstract
- Species invasions are a global problem of increasing concern, especially in highly connected aquatic environments. Despite this, salinity conditions can pose physiological barriers to their spread, and understanding them is important for management. In Scandinavia's largest cargo port, the invasive round goby (Neogobius melanostomus) is established across a steep salinity gradient. We used 12,937 SNPs to identify the genetic origin and diversity of three sites along the salinity gradient and round goby from western, central and northern Baltic Sea, as well as north European rivers. Fish from two sites from the extreme ends of the gradient were also acclimated to freshwater and seawater, and tested for respiratory and osmoregulatory physiology. Fish from the high-salinity environment in the outer port showed higher genetic diversity, and closer relatedness to the other regions, compared to fish from lower salinity upstream the river. Fish from the high-salinity site also had higher maximum metabolic rate, fewer blood cells and lower blood Ca2+. Despite these genotypic and phenotypic differences, salinity acclimation affected fish from both sites in the same way: seawater increased the blood osmolality and Na+ levels, and freshwater increased the levels of the stress hormone cortisol. Our results show genotypic and phenotypic differences over short spatial scales across this steep salinity gradient. These patterns of the physiologically robust round goby are likely driven by multiple introductions into the high-salinity site, and a process of sorting, likely based on behaviour or selection, along the gradient. This euryhaline fish risks spreading from this area, and seascape genomics and phenotypic characterization can inform management strategies even within an area as small as a coastal harbour inlet.
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| 7. |
- Kvarnemo, Charlotta, et al.
(författare)
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Fish ART & sperm performance
- 2023
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Konferensbidrag (refereegranskat)abstract
- In species with alternative reproductive tactics (ART), parasitically spawning males have larger testes and greater sperm numbers as an evolved response to a higher degree of sperm competition. But do they also have higher sperm performance? We used sand gobies to test if it differs between breeding-coloured and sneaker-morph males. We compared sperm motility, velocity, longevity, morphometrics and gene expression of testes between the two morphs. We found 109 transcripts differentially expressed between the morphs. Notably, several mucin genes were upregulated in breeding-coloured males and two ATP-related genes were upregulated in sneaker-morph males. There was partial evidence of higher sperm velocity in sneaker-morph males, but no difference in sperm motility. Sand gobies have remarkably long-lived sperm, with almost no decline in motility and velocity over 22 hours, but again, this was equally true for both morphs. Sperm length did not differ between morphs and did not correlate with sperm velocity for either morph. Thus, other than a clear difference in testes gene expression, we found only modest differences between the two male morphs, confirming previous findings that increased sperm performance as an adaptation to sperm competition does not appear to be a primary target of evolution.
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| 8. |
- Kvarnemo, Charlotta, 1963, et al.
(författare)
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Molecular, behavioural and morphological comparisons of sperm adaptations in a fish with alternative reproductive tactics
- 2023
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Ingår i: Evolutionary Applications. - : Wiley. - 1752-4571. ; 16:2, s. 338-53
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Tidskriftsartikel (refereegranskat)abstract
- In species with alternative reproductive tactics, there is much empirical support that parasitically spawning males have larger testes and greater sperm numbers as an evolved response to a higher degree of sperm competition, but support for higher sperm performance (motility, longevity and speed) by such males is inconsistent. We used the sand goby (Pomatoschistus minutus) to test whether sperm performance differed between breeding-coloured males (small testes, large mucus-filled sperm-duct glands; build nests lined with sperm-containing mucus, provide care) and parasitic sneaker-morph males (no breeding colouration, large testes, rudimentary sperm-duct glands; no nest, no care). We compared motility (per cent motile sperm), velocity, longevity of sperm, gene expression of testes and sperm morphometrics between the two morphs. We also tested if sperm-duct gland contents affected sperm performance. We found a clear difference in gene expression of testes between the male morphs with 109 transcripts differentially expressed between the morphs. Notably, several mucin genes were upregulated in breeding-coloured males and two ATP-related genes were upregulated in sneaker-morph males. There was a partial evidence of higher sperm velocity in sneaker-morph males, but no difference in sperm motility. Presence of sperm-duct gland contents significantly increased sperm velocity, and nonsignificantly tended to increase sperm motility, but equally so for the two morphs. The sand goby has remarkably long-lived sperm, with only small or no decline in motility and velocity over time (5 min vs. 22 h), but again, this was equally true for both morphs. Sperm length (head, flagella, total and flagella-to-head ratio) did not differ between morphs and did not correlate with sperm velocity for either morph. Thus, other than a clear difference in testes gene expression, we found only modest differences between the two male morphs, confirming previous findings that increased sperm performance as an adaptation to sperm competition is not a primary target of evolution.
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| 9. |
- Raymond, Caroline, et al.
(författare)
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Miljöövervakning av mjukbottenfauna i Gotlands kustområden, 2018-2019 : KLintehamn, Slite och Fårösund samt När-Östergarn
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna rapport redovisar resultaten av 2018–2019 års undersökning av mjukbottenfaunan inom det nya nationellt-regionalt samordnade programmet i Gotlands län. Programmet undersöker långsiktiga och storskaliga förändringar av referensområden i Egentliga Östersjön som en effekt av främst övergödning och syrebrist i bottenvattnet samt följer den biologiska mångfalden. I det nya programmet (sedan 2016) provtas dels det nationella klustret NAT När öster om Gotland, dels tre regionala kluster (Slite, Klintehamn och Fårösund). I det nya stationsnätet har fem stationer från det tidigare klustret REG När ersatt fem tidigare provtagna stationer i klustret NAT När. Alla stationerna är provtagna sedan 2007, men data från NAT När i det nya programmet är pga denna förändring av stationer inte jämförbara med dem i rapporterna innan 2016. De aktuella regionala klustren vid Slite, Klintehamn och Fårösund har tidigare undersökts under 2006, 2008, 2011 och 2014. För dessa områden utgörs den största förändringen i det nya programmet av att de provtas vartannat år, dvs med en högre provtagningsfrekvens, och att sex stationer provtas i varje kluster i stället för tidigare fem. Det primära syftet med undersökningen är att enligt EU:s vattendirektiv bedöma miljöstatus. Detta sker med hjälp av Benthic Quality Index (BQI) som baseras på makrofaunans sammansättning. De årligen besökta stationerna som ingår i det nya klustret NAT När har uppvisat god status årligen sedan 2007. Även områdena utanför Slite och Klintehamn har uppvisat god status vid alla undersökningstillfällen. I området Fårösund däremot har status varierat; måttlig 2006, god 2008, otillfredsställande 2011, god 2014 samt slutligen åter måttlig status 2017 och 2019.
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| 10. |
- Svensson, Ola, 1971-, et al.
(författare)
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Behavioural and genomic analyses of locally adapted sand goby populations over a steep salinity gradient
- 2023
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Konferensbidrag (refereegranskat)abstract
- Studies of colonization of new habitats appearing from rapidly changing environments increase our understanding of populations’ potential to cope with environmental changes. Here, we analyse behavioural, phenotypic and genetic variation involved in the successful establishment of the sand goby, Pomatoschistus minutus, over a steep salinity drop from 35 PSU in the North Sea (NE Atlantic) to two PSU in the inner parts of the post-glacial Baltic Sea. We show e.g. that populations are adapted to local salinity in a key reproductive trait, the proportion of motile sperm, which in itself may result in reproductive isolation caused by natural selection on immigrants. Genome variation shows strong differentiation among populations along the gradient. Sand gobies in the current Baltic Sea lineage is adapted to the low salinity in traits related to osmoregulation and reproduction, but also to both abiotic and biotic environmental factors correlated to salinity evident in traits such as vision and immune function. The salinity-biotic factors correlation is omnipresent in behavioral studies. Many loci also appear to be involved in these traits, but the specific functional mechanism (e.g., coding sequence, regulatory loci) remains to be clarified. We conclude that the first steps on the speciation continuum trajectory have been taken.
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