| 1. |
- Semb, Gunvor, et al.
(författare)
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A Scandcleft randomised trials of primary surgery for unilateral cleft lip and palate: 1. Planning and management.
- 2017
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Ingår i: Journal of Plastic Surgery and Hand Surgery. - : Taylor & Francis. - 2000-656X .- 2000-6764. ; 51:1, s. 2-13
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND AIMS: Longstanding uncertainty surrounds the selection of surgical protocols for the closure of unilateral cleft lip and palate, and randomised trials have only rarely been performed. This paper is an introduction to three randomised trials of primary surgery for children born with complete unilateral cleft lip and palate (UCLP). It presents the protocol developed for the trials in CONSORT format, and describes the management structure that was developed to achieve the long-term engagement and commitment required to complete the project.METHOD: Ten established national or regional cleft centres participated. Lip and soft palate closure at 3-4 months, and hard palate closure at 12 months served as a common method in each trial. Trial 1 compared this with hard palate closure at 36 months. Trial 2 compared it with lip closure at 3-4 months and hard and soft palate closure at 12 months. Trial 3 compared it with lip and hard palate closure at 3-4 months and soft palate closure at 12 months. The primary outcomes were speech and dentofacial development, with a series of perioperative and longer-term secondary outcomes.RESULTS: Recruitment of 448 infants took place over a 9-year period, with 99.8% subsequent retention at 5 years.CONCLUSION: The series of reports that follow this introductory paper include comparisons at age 5 of surgical outcomes, speech outcomes, measures of dentofacial development and appearance, and parental satisfaction. The outcomes recorded and the numbers analysed for each outcome and time point are described in the series.TRIAL REGISTRATION: ISRCTN29932826.
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| 2. |
- Backström, Niclas, et al.
(författare)
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The recombination landscape of the zebra finch Taeniopygia guttata genome
- 2010
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1088-9051 .- 1549-5469. ; 20:4, s. 485-495
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the causes and consequences of variation in the rate of recombination is essential since this parameter is considered to affect levels of genetic variability, the efficacy of selection, and the design of association and linkage mapping studies. However, there is limited knowledge about the factors governing recombination rate variation. We genotyped 1920 single nucleotide polymorphisms in a multigeneration pedigree of more than 1000 zebra finches (Taeniopygia guttata) to develop a genetic linkage map, and then we used these map data together with the recently available draft genome sequence of the zebra finch to estimate recombination rates in 1 Mb intervals across the genome. The average zebra finch recombination rate (1.5 cM/Mb) is higher than in humans, but significantly lower than in chicken. The local rates of recombination in chicken and zebra finch were only weakly correlated, demonstrating evolutionary turnover of the recombination landscape in birds. The distribution of recombination events was heavily biased toward ends of chromosomes, with a stronger telomere effect than so far seen in any organism. In fact, the recombination rate was as low as 0.1 cM/Mb in intervals up to 100 Mb long in the middle of the larger chromosomes. We found a positive correlation between recombination rate and GC content, as well as GC-rich sequence motifs. Levels of linkage disequilibrium (LD) were significantly higher in regions of low recombination, showing that heterogeneity in recombination rates have left a footprint on the genomic landscape of LD in zebra finch populations.
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| 3. |
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| 4. |
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| 5. |
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| 6. |
- Bolund, Elisabeth, et al.
(författare)
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Correlates of male fitness in captive zebra finches : a comparison of methods to disentangle genetic and environmental effects
- 2011
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Ingår i: BMC Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 11, s. 327-
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Tidskriftsartikel (refereegranskat)abstract
- Backgound: It is a common observation in evolutionary studies that larger, more ornamented or earlier breeding individuals have higher fitness, but that body size, ornamentation or breeding time does not change despite of sometimes substantial heritability for these traits. A possible explanation for this is that these traits do not causally affect fitness, but rather happen to be indirectly correlated with fitness via unmeasured non-heritable aspects of condition (e. g. undernourished offspring grow small and have low fitness as adults due to poor health). Whether this explanation applies to a specific case can be examined by decomposing the covariance between trait and fitness into its genetic and environmental components using pedigree-based animal models. We here examine different methods of doing this for a captive zebra finch population where male fitness was measured in communal aviaries in relation to three phenotypic traits (tarsus length, beak colour and song rate). Results: Our case study illustrates how methods that regress fitness over breeding values for phenotypic traits yield biased estimates as well as anti-conservative standard errors. Hence, it is necessary to estimate the genetic and environmental covariances between trait and fitness directly from a bivariate model. This method, however, is very demanding in terms of sample sizes. In our study parameter estimates of selection gradients for tarsus were consistent with the hypothesis of environmentally induced bias (beta(A) = 0.035 +/- 0.25 (SE), beta(E) = 0.57 +/- 0.28 (SE)), yet this differences between genetic and environmental selection gradients falls short of statistical significance. Conclusions: To examine the generality of the idea that phenotypic selection gradients for certain traits (like size) are consistently upwardly biased by environmental covariance a meta-analysis across study systems will be needed.
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| 7. |
- Bolund, Elisabeth, et al.
(författare)
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Effects of the demographic transition on the genetic variances and covariances of human life-history traits
- 2015
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Ingår i: Evolution. - : Wiley. - 0014-3820 .- 1558-5646. ; 69:3, s. 747-755
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Tidskriftsartikel (refereegranskat)abstract
- The recent demographic transitions to lower mortality and fertility rates in most human societies have led to changes and even quick reversals in phenotypic selection pressures. This can only result in evolutionary change if the affected traits are heritable, but changes in environmental conditions may also lead to subsequent changes in the genetic variance and covariance (the G matrix) of traits. It currently remains unclear if there have been concomitant changes in the G matrix of life-history traits following the demographic transition. Using 300 years of genealogical data from Finland, we found that four key life-history traits were heritable both before and after the demographic transition. The estimated heritabilities allow a quantifiable genetic response to selection during both time periods, thus facilitating continued evolutionary change. Further, the G matrices remained largely stable but revealed a trend for an increased additive genetic variance and thus evolutionary potential of the population after the transition. Our results demonstrate the validity of predictions of evolutionary change in human populations even after the recent dramatic environmental change, and facilitate predictions of how our biology interacts with changing environments, with implications for global public health and demography.
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| 8. |
- Bolund, Elisabeth, et al.
(författare)
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Reduced costs of reproduction in females mediate a shift from a male-biased to a female-biased lifespan in humans
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- The causes underlying sex differences in lifespan are strongly debated. While females commonly outlive males in humans, this is generally less pronounced in societies before the demographic transition to low mortality and fertility rates. Life-history theory suggests that reduced reproduction should benefit female lifespan when females pay higher costs of reproduction than males. Using unique longitudinal demographic records on 140,600 reproducing individuals from the Utah Population Database, we demonstrate a shift from male-biased to female-biased adult lifespans in individuals born before versus during the demographic transition. Only women paid a cost of reproduction in terms of shortened post-reproductive lifespan at high parities. Therefore, as fertility decreased over time, female lifespan increased, while male lifespan remained largely stable, supporting the theory that differential costs of reproduction in the two sexes result in the shifting patterns of sex differences in lifespan across human populations. Further, our results have important implications for demographic forecasts in human populations and advance our understanding of lifespan evolution.
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| 9. |
- Bolund, Elisabeth
(författare)
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The challenge of measuring trade-offs in human life history research
- 2020
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Ingår i: Evolution and human behavior. - : Elsevier BV. - 1090-5138 .- 1879-0607. ; 41:6, s. 502-512
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Tidskriftsartikel (refereegranskat)abstract
- Life history theory has become a prominent framework in the evolutionary social sciences, and the concept of trade-offs, the cornerstone of life history theory in studies on non-human taxa, has likewise been widely adopted. Yet, human life history research often assumes trade-offs without demonstrating them. This is not surprising given the practical difficulties in measuring trade-offs in long-lived animals, like humans. Four main methods are used to demonstrate trade-offs: phenotypic correlations, experimental manipulations, genetic correlations and correlated responses to selection. Here, I discuss challenges with these methods along with potential solutions. For example, individual heterogeneity within a population in quality or access to resources can mask underling trade-offs, and this can be accounted for by careful experimental manipulation or proper statistical treatment of observational data. In general, trade-offs have proven more difficult than expected to measure, and evidence across species is mixed, but strong evidence exists in some cases. I use the key trade-off between reproduction and survival to exemplify methods, challenges and solutions, and review the mixed evidence for a cost of reproduction in humans. I conclude by providing directions for future research. Promising avenues are opening thanks to recent advances in quantitative genetic and genomic methods coupled with the availability of high-quality large-scale datasets on humans from different populations, allowing the study of the evolutionary implications of life history trade-offs in humans.
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| 10. |
- Bolund, Elisabeth, et al.
(författare)
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The effects of resource availability and the demographic transition on the genetic correlation between number of children and grandchildren in humans
- 2017
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Ingår i: Heredity. - : NATURE PUBLISHING GROUP. - 0018-067X .- 1365-2540. ; 118:2, s. 186-192
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Tidskriftsartikel (refereegranskat)abstract
- Studies of evolutionary change require an estimate of fitness, and lifetime reproductive success is widely used for this purpose. However, many species face a trade-off between the number and quality of offspring and in such cases number of grandoffspring may better represent the genetic contribution to future generations. Here, we apply quantitative genetic methods to a genealogical data set on humans from Finland to address how the genetic correlation between number of children and grandchildren is influenced by the severity of the trade-off between offspring quality and quantity, as estimated by different levels of resource access among individuals in the population. Further, we compare the genetic correlation before and after the demographic transition to low mortality and fertility rates. The genetic correlation was consistently high (0.79-0.92) with the strongest correlations occurring in individuals with higher access to resources and before the demographic transition, and a tendency for lower correlations in resource poor individuals and after the transition. These results indicate that number of grandoffspring is a slightly better predictor of long-term genetic fitness than number of offspring in a human population across a range of environmental conditions, and more generally, that patterns of resource availability need to be taken into account when estimating genetic covariances with fitness.
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| 11. |
- Bruckner, Tim A., et al.
(författare)
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Culled males, infant mortality and reproductive success in a pre-industrial Finnish population
- 2015
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 282:1799
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Tidskriftsartikel (refereegranskat)abstract
- Theoretical and empirical literature asserts that the sex ratio (i.e. M/F) at birth gauges the strength of selection in utero and cohort quality of males that survive to birth. We report the first individual-level test in humans, using detailed life-history data, of the 'culled cohort' hypothesis that males born to low annual sex ratio cohorts show lower than expected infant mortality and greater than expected lifetime reproductive success. We applied time-series and structural equation methods to a unique multi-generational dataset of a natural fertility population in nineteenth century Finland. We find that, consistent with culled cohorts, a 1 s.d. decline in the annual cohort sex ratio precedes an 8% decrease in the risk of male infant mortality. Males born to lower cohort sex ratios also successfully raised 4% more offspring to reproductive age than did males born to higher cohort sex ratios. The offspring result, however, falls just outside conventional levels of statistical significance. In historical Finland, the cohort sex ratio gauges selection against males in utero and predicts male infant mortality. The reproductive success findings, however, provide weak support for an evolutionarily adaptive explanation of male culling in utero.
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| 12. |
- Griffin, Robert M., et al.
(författare)
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Sex differences in adult mortality rate mediated by early-life environmental conditions
- 2018
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Ingår i: Ecology Letters. - : WILEY. - 1461-023X .- 1461-0248. ; 21:2, s. 235-242
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Tidskriftsartikel (refereegranskat)abstract
- Variation in sex differences is affected by both genetic and environmental variation, with rapid change in sex differences being more likely due to environmental change. One case of rapid change in sex differences is human lifespan, which has become increasingly female-biased in recent centuries. Long-term consequences of variation in the early-life environment may, in part, explain such variation in sex differences, but whether the early-life environment mediates sex differences in life-history traits is poorly understood in animals. Combining longitudinal data on 60 cohorts of pre-industrial Finns with environmental data, we show that the early-life environment is associated with sex differences in adult mortality and expected lifespan. Specifically, low infant survival rates and high rye yields (an important food source) in early-life are associated with female-bias in adult lifespan. These results support the hypothesis that environmental change has the potential to affect sex differences in life-history traits in natural populations of long-lived mammals.
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| 13. |
- Larsson, Stefan, et al.
(författare)
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Bedömning av status för nationellt förvaltade fisk- och skaldjursbestånd
- 2024
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Institutionen för akvatiska resurser vid Sveriges lantbruksuniversitet (SLU Aqua) presenterar årligen statusbedömningar för nationellt förvaltade fisk- och skaldjursbestånd i svenska vatten på webbportalen www.fiskbarometern.se. Fiskbarometerns statusbedömningar av fisk- och skaldjursbestånd, utgör ett viktigt underlag för hållbart nyttjande, bevarandeåtgärder och uppföljning inom fisk-, vatten- och miljöförvaltningen. I denna rapport redovisas metodiken för dessa statusbedömningar. Metodiken bidrar till en standardiserad och kvalitetssäkrad bedömningsprocess som är transparent och som vilar på vetenskaplig grund. För de flesta bestånd i Fiskbarometern baseras bedömningen på indikatorer indelade i dödlighet, biomassa/abundans och storleks-/åldersstruktur, vilka motsvarar Havsmiljödirektivets tre kriterier för bedömning av kommersiellt nyttjade bestånd (2008/56/EC). Baserat på sammanvägningen av de tre kriterierna ges respektive bestånd sedan en av fem möjliga statusbedömningar:• kan ej bedömas • mycket sannolikt inte inom biologiskt säkra gränser • sannolikt inte inom biologiskt säkra gränser • sannolikt inom biologiskt säkra gränser • mycket sannolikt inom biologiskt säkra gränserFör några nationellt förvaltade bestånd finns eller pågår arbete med att utveckla analytiska beståndsmodeller. I den här rapporten presenteras riktlinjer för kvalitetssäkring och tillämpning av dem översiktligt, men den vetenskapliga granskningen av sådana modeller hanteras separat inom en process som kallas riktmärkning, vilken inte beskrivs i denna rapport. Utfall från dessa modeller översätts till samma statuskategorier som för de indikatorbaserade bedömningarna.
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| 14. |
- Schielzeth, Holger, et al.
(författare)
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Patterns of conspecific brood parasitism in zebra finches
- 2010
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 79:6, s. 1329-1337
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Tidskriftsartikel (refereegranskat)abstract
- Conspecific brood parasitism (CBP) brings the obvious fitness advantage of decreased breeding costs. However, the successful development of parasitic eggs depends on appropriate timing in relation to the host's own eggs. A detailed documentation of CBP requires full knowledge of parentage. We achieved this in a captive population of zebra finches, Taeniopygia guttata, breeding in aviaries. The overall frequency of CBP was relatively high (21% of all host clutches, 5.4% of all eggs in host clutches) and comparable to what has been found in the wild in this species. A large proportion of paired females adopted a mixed strategy, laying one or two additional eggs in other nests before initiating their own clutches. Females showed a high individual consistency in whether they adopted a pure nonparasitic strategy or a mixed strategy, which is indicative of individual specialization. About 38% of all eggs laid outside a pair's own nest were incubated by host pairs and can thus be considered successfully parasitic. No paired females were purely parasitic but unpaired females used CBP as a best of a bad job strategy. Hosts were targeted during the early phase of clutch initiation with the majority of parasitic eggs laid 0-5 days before the onset of incubation and usually before the host commenced egg laying. We did not find evidence that particular types of host females were targeted. The within-female repeatability of being a host was estimated to be negative. Overall, the systematic temporal patterns indicate targeted CBP behaviour in zebra finches.
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| 15. |
- Schielzeth, Holger, et al.
(författare)
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Quantitative genetics and fitness consequences of neophilia in zebra finches
- 2011
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Ingår i: Behavioral Ecology. - : Oxford University Press (OUP). - 1045-2249 .- 1465-7279. ; 22:1, s. 126-134
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Tidskriftsartikel (refereegranskat)abstract
- Consistent between-individual differences in context-general behavioral traits (often called personality traits) are particularly interesting for behavioral ecologists because they might show unexpected cross-context correlations and explain maladaptive behavior. In order to understand their evolutionary significance, it is relevant to know the heritability of these traits and how they relate to reproductive success. This might give insights into selective processes that maintain variation as well as into potential trade-offs. We scored approach to novel objects of 530 captive zebra finches in a familiar environment. Scores were highly repeatable and showed substantial additive genetic variation. We measured reproductive success, promiscuity, and extrapair paternity rates under aviary conditions and calculated linear and nonlinear selection differentials based on fertilization success as well as effects on chick-rearing success of pairs. Approach to novel objects had little influence on these components of reproductive success. However, we found that the social environment ( manipulated operational sex ratios) influenced the correlation between approach to a novel object and the proportion of extrapair paternity. We also found that the sex ratio manipulation affected measures of the intensity of sexual selection. Both effects were stronger in males than in females. We conclude that despite the lack of differences in overall reproductive success, approach to novel objects reflects variation in reproductive strategies.
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| 16. |
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| 17. |
- Sekajova, Zuzana, et al.
(författare)
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Evolution during uncorrelated environmental fluctuations : bet-hedging or phenotypic plasticity?
- 2023
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Evolution in fluctuating environments is predicted to select for phenotypic plasticity or bet-hedging, depending on the accuracy of environmental cues and type of fluctuations. While these two alternatives are often contrasted in theoretical studies, their evolution are seldom studied together in empirical work.We used experimental evolution in the nematode worm Caenorhabditis remanei to simultaneously study the evolution of plasticity and bet-hedging in environments differing only in their temperature variability. We exposed worms for 30 generations to either fast fluctuating or slowly increasing temperature, these two environments had the same average temperature over evolutionary time. After experimental evolution, we scored size at sexual maturity and fitness in full siblings reared in two different temperatures, optimal 20°C and mildly stressful 25°C.Experimental evolution in the fluctuating environment resulted in the evolution of increased body size plasticity but not increased bet-hedging, compared to evolution in the slowly changing environment. Plasticity followed the temperature size rule as size decreased with increasing temperature and this plastic response was adaptive. In addition, we discovered substantial standing genetic variation in body size, which represents a potential for further evolutionary change.
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| 18. |
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| 19. |
- Stångberg, Josefine, 1988-
(författare)
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Evolutionary consequences of sex-specific selection
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Sex-specific selection is widespread, evident by the evolution of sexual dimorphism in many traits in sexually reproducing taxa. The reason why the sexes may experience selection that differs in direction or magnitude is often linked to the reproductive strategies associated with the sex-specific reproductive physiology. Competition for mates or fertilisations creates conditions where selection is sex-specific and may overall be stronger on the sex experiencing more competition. However, the sexes share a majority of their genome and consequently many traits may be genetically correlated between the sexes, constraining sex-specific adaptation. In paper I, II and III, I investigate the consequences of exposure to altered strength of sex-specific selection in the laboratory through 30 generations of experimental evolution with skewed sex ratios, using the sexually reproducing nematode Caenorhabditis remanei as a model organism. I created female-biased (FB) and male-biased (MB) treatments. In paper I, I investigated the phenotypic response to selection in three life history traits (body size, fitness and heat shock resistance as a proxy for somatic maintenance). I found a sex-specific response to the evolutionary treatments for body size and fitness, while somatic maintenance was similarly affected by the treatments in the sexes. Subsequently, in paper II, I examined sex-specific patterns of additive genetic variance (VA) for reproductive fitness, and estimated the intersexual genetic correlation (rmf) of fitness. Results show low levels of VA for fitness, and no changes in response to treatments. Values of rmf are associated with large uncertainties, highlighting the difficulties in estimating and interpreting rmf for fitness. In paper III, I used a multivariate approach to investigate the sex-specific genetic variance-covariance matrices (GF and GM), and the between-sex genetic covariance matrix (B) in the three life history traits. Results show no genetic covariances between the traits, and no covariances between the sexes in these traits. The sex-specific G-matrices also remained stable in response to the treatments. These results therefore suggest that the genetic architecture of the traits studied here does not constrain the independent evolution in the sexes. In paper IV, using the seed beetle Callosobruchus maculatus as the model, I find that experimentally induced mutations have stronger negative effects on male than female fitness, suggesting overall stronger selection on males. The results support the theory that strong sexual selection on males have the potential to purge deleterious mutations from a population.
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| 20. |
- Stångberg, Josefine, 1988-, et al.
(författare)
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Experimentally induced intrasexual mating competition and sex‐specific evolution in female and male nematodes
- 2020
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Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 33:12, s. 1677-1688
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Tidskriftsartikel (refereegranskat)abstract
- Sexual dimorphism in life history traits and their trade‐offs is widespread among sexually reproducing animals and is strongly influenced by the differences in reproductive strategies between the sexes. We investigated how intrasexual competition influenced specific life history traits, important to fitness and their trade‐offs in the outcrossing nematode Caenorhabditis remanei. Here, we altered the strength of sex‐specific selection through experimental evolution with increased potential for intrasexual competition by skewing the adult sex ratio towards either females or males (1:10 or 10:1) over 30 generations and subsequently measured the phenotypic response to selection in three traits related to fitness: body size, fecundity and tolerance to heat stress. We observed a greater evolutionary change in females than males for body size and peak fitness, suggesting that females may experience stronger net selection and potentially harbour higher amounts of standing genetic variance compared to males. Our study highlights the importance of investigating direct and indirect effects of intrasexual competition in both sexes in order to capture sex‐specific responses and understand the evolution of sexual dimorphism in traits expressed by both sexes.
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| 21. |
- Stångberg, Josefine, 1988-, et al.
(författare)
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Sex-specific additive genetic variance for fitness during experimental evolution in a sexually reproducing nematode.
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Variation in fitness defines the upper limit of adaptive evolution. Due to an intersexual genetic correlation (rmf) for fitness, the sexes could act as a constraint for the sex-specific evolution of fitness. Additive genetic variance VA is generally lower for fitness than for other traits (such as morphological traits), and its estimation can be challenging. Little is known about how VA and rmf for fitness are affected by sex-specific selection over time. Here, we estimated sex-specific VA and rmf between the sexes for a measure of relative fitness in the outcrossing nematode Caenorhabditis remanei and tested how VA and rmf are affected by evolution under experimentally increased sexual competition. For this we used experimental evolution treatments of skewed sex ratios, creating 1:10 female-biased (FB) and male-biased (MB) conditions, for 30 generations. In line with many other studies we found only a small amount of VA for fitness in both sexes. There was, however, a trend of males having approximately double the amount of VA for fitness than females across the treatments, but no differences between treatments in either sex were detected. Rmf mean values differed across treatments, but these values were estimated with some uncertainty and the differences were not statistically significant. The results indicate that VA for a measure of fitness did not change in response to skewed sex ratios, and males harboured a greater amount of VA for fitness than females, in line with findings in many other systems. This study, being one of the few studies combining quantitative genetics and experimental evolution, highlights the challenge of estimating sex-specific VA for fitness, as well as the complexity of using and interpreting intersexual genetic correlations (rmf).
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| 22. |
- Stångberg, Josefine, 1988-, et al.
(författare)
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Stability of the G- and B-matrices in life history traits under experimental manipulation of sexual competition.
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- How sexual dimorphism in life history traits evolves, despite a majority of the genome being shared between the sexes, is a fundamental question in evolutionary biology. To answer this question, we need to understand how traits vary within the sexes, and how they covary between the sexes. Constructing genetic variance-covariance matrices (G) for each sex (GF and GM), and between-sex covariance matrices (B), gives us the genetic architecture of traits within and between the sexes. These matrices can be used to predict sex-specific evolutionary trajectories in a population. Understanding the stabilities of G and B over evolutionary time is key in elucidating how sexual dimorphism evolves despite a shared genome, and one way to test the stability of matrices is to use experimental evolution. In this study, we manipulated ratios separately towards each sex in the nematode Caenorhabditis remanei (female-biased, FB, and male-biased, MB), and let populations evolve under these environments for 30 generations, and subsequently compared them to the ancestral population. We measured three important life history traits (body size, peak reproductive fitness and heat shock tolerance as a proxy for somatic maintenance), estimated standardised phenotypic selection gradients, and constructed GF, GM, and B for each sex and treatment. The three life history traits showed no significant genetic covariances in either sex, and these within-sex G-matrices were similar between the experimental treatments. No significant trait covariances were detected between the sexes either, and the B-matrices also remained similar across the treatments. These results suggest that the genetic architecture of life history traits studied here is largely independent across traits and sexes, and remains stable despite previously reported phenotypic evolution in response to the sex ratio manipulations. There seems to be little constraint to the independent evolution in the sexes, in line with the widespread observation of sexual dimorphism in life history traits. Our results suggest that the directional and stabilising selection gradients for body size has changed in a sex-specific manner in response to treatments.
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| 23. |
- Sundelöf, Andreas, et al.
(författare)
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Fisk- och skaldjursbestånd i hav och sötvatten 2021 : Resursöversikt
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I rapporten kan du ta del av bedömningen som görs av situationen för bestånd som regleras inom ramen för EU:s gemensamma fiskeripolitik (GFP). Bedömningarna baseras på det forskningssamarbete och den rådgivning som sker inom det Internationella Havsforskningsrådet (ICES). Sammantaget redovisas tillståndet för 107 bestånd av 48 fisk- och skaldjursarter.De bestånd som förvaltas nationellt baseras på de biologiska underlagen, och rådgivningen i huvudsak på den forskning och övervakning samt analys som bedrivs av Institutionen för akvatiska resurser vid Sveriges lantbruksuniversitet (SLU Aqua) samt yrkesfiskets rapportering.Rapporten är en beställning från Havs- och vattenmyndigheten (HaV) till Sveriges lantbruksuniversitet (SLU) och utgör ett viktigt kunskapsunderlag till myndighetens arbete. Den uppfyller de krav som finns inom EU:s gemensamma fiskeripolitik om att basera förvaltningen på bästa tillgängliga vetenskap. Denna rapport är också ett stöd till det arbete som beskrivs närmare i strategin för framtidens fiske och tillhörande handlingsplaner för vattenbruk, yrkes- och fritidsfiske som HaV och Jordbruksverket har tagit fram i dialog med fiskets och vattenbrukets intressenter.
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| 24. |
- Östman, Örjan, et al.
(författare)
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Size-based indicators for assessments of ecological status of coastal fish communities
- 2023
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Ingår i: ICES Journal of Marine Science. - 1054-3139 .- 1095-9289. ; 80, s. 2478-2489
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Tidskriftsartikel (refereegranskat)abstract
- Human impact does not only affect the abundances of fish, but also the age- and size-distributions. Indicators of fish age and size-structures can hence be useful tools for fisheries- and environmental management. Size-based indicators have been tested and proposed for large, homogenous marine ecosystems with high fishing mortality, but rarely for fine-scaled heterogeneous ecosystems in coastal zones. Here we analyse a suite of size indicators for coastal fish communities in the Baltic Sea, including mean and median length, 10th and 90th-percentile of the length distribution (L10, L90), mean length of the 10% largest fish (Lmax), large fish indices, size-spectra, and size-diversity. Results show good precision and accuracy of most indicators at realistic sample sizes, except for size-spectra and size-diversity, making them less suitable. Different indicators showed correlations among sites, indicating similar responses to environmental variation. Most size indicators responded positively to lower fishing pressure, especially indicators emphasizing the largest individuals in the population (e.g. L90 and Lmax), whereas eutrophication and physical disturbances had less impact. We conclude that size-based indicators aiming at describing the occurrence of larger fish, like L90 and Lmax, are useful for establishing management targets and assessing the status of coastal fish.
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