Density-dependent selection and the maintenance of colour polymorphism in barn owls

The capacity of natural selection to generate adaptive changes is (according to the fundamental theorem of natural selection) proportional to the additive genetic variance in fitness. In spite of its importance for development of new adaptations to a changing environment, processes affecting the magnitude of the genetic variance in fitness-related traits are poorly understood. Here, we show that the red-white colour polymorphism in female barn owls is subject to density-dependent selection at the phenotypic and genotypic level. The diallelic melanocortin-1 receptor gene explained a large amount of the phenotypic variance in reddish coloration in the females (R2 ¼ 59:8%). Red individuals (RR genotype) were selected for at low densities, while white individuals (WW genotype) were favoured at high densities and were less sensitive to changes in density.We show that this density-dependent selection favours white individuals and predicts fixation of the white allele in this population at longer time scales without immigration or other selective forces. Still, fluctuating population density will cause selection to fluctuate and periodically favour red individuals. These results suggest how balancing selection caused by fluctuations in population density can be a general mechanism affecting the level of additive genetic variance in natural populations.Density-dependent selection and the maintenance of colour polymorphism in barn owlspublishedVersio

Does availability of resources influence grazing strategies in female Svalbard reindeer?

Foraging strategies and range use in wild female Svalbard reindeer (Rangifer tarandus platyrhynchus) were studied in two areas where the historical grazing pressure differed. We mapped vegetation where the reindeer were seen grazing, and related forage availability to characteristics such as home range size, activity budgets and reproductive status. There were significant differences in quantity of forage available between the two areas and the utilization of vegetation types differed between the sites. However, we found no difference in home range size between the two sites, and individual home range sizes were not related to forage quantity, possibly a result of a skewed and small sample size. Even though significant differences in availability of plant species and groups were found, no variation in home range size was found between reproductive and non-reproductive females on Brøggerhalvøya. Neither did we find any differences between areas or between reproductive groups within or between areas in how female reindeer allocated use of time, or in number of steps taken. However, a significant three way interaction indicated that some variance existed between reproductive groups within or between areas, but we do not conclude that this indicate different grazing strategies. Thus, even though variation in the duration of previous grazing has evidently resulted in rather different foraging conditions in our two areas, we detected no differences in present-day foraging behaviour. Thus, our analyses suggest no relationship or feedback between past grazing and current foraging behaviour in these reindeer

Effects of local density dependence and temperature on the spatial synchrony of marine fish populations

Disentangling empirically the many processes affecting spatial population synchrony is a challenge in population ecology. Two processes that could have major effects on the spatial synchrony of wild population dynamics are density dependence and variation in environmental conditions like temperature. Understanding these effects is crucial for predicting the effects of climate change on local and regional population dynamics. We quantified the direct contribution of local temperature and density dependence to spatial synchrony in the population dynamics of nine fish species inhabiting the Barents Sea. First, we estimated the degree to which the annual spatial autocorrelations in density are influenced by temperature. Second, we estimated and mapped the local effects of temperature and strength of density dependence on annual changes in density. Finally, we measured the relative effects of temperature and density dependence on the spatial synchrony in changes in density. Temperature influenced the annual spatial autocorrelation in density more in species with greater affinities to the benthos and to warmer waters. Temperature correlated positively with changes in density in the eastern Barents Sea for most species. Temperature had a weak synchronizing effect on density dynamics, while increasing strength of density dependence consistently desynchronised the dynamics. Quantifying the relative effects of different processes affecting population synchrony is important to better predict how population dynamics might change when environmental conditions change. Here, high degrees of spatial synchrony in the population dynamics remained unexplained by local temperature and density dependence, confirming the presence of additional synchronizing drivers, such as trophic interactions or harvesting.publishedVersio

Age-dependent patterns of spatial autocorrelation in fish populations

The degree of spatial autocorrelation in population fluctuations increases with dispersal and geographical covariation in the environment, and decreases with strength of density dependence. Because the effects of these processes can vary throughout an individual’s lifespan, we studied how spatial autocorrelation in abundance changed with age in three marine fish species in the Barents Sea. We found large interspecific differences in age-dependent patterns of spatial autocorrelation in density. Spatial autocorrelation increased with age in cod, the reverse trend was found in beaked redfish, while it remained constant among age classes in haddock. We also accounted for the average effect of local cohort dynamics, i.e. the expected local density of an age class given last year’s local density of the cohort, with the goal of disentangling spatial autocorrelation patterns acting on an age class from those formed during younger age classes and being carried over. We found that the spatial autocorrelation pattern of older age classes became increasingly determined by the distribution of the cohort during the previous year. Lastly, we found high degrees of autocorrelation over long distances for the three species, suggesting the presence of far-reaching autocorrelating processes on these populations. We discuss how differences in the species’ life history strategies could cause the observed differences in age-specific variation in spatial autocorrelation. As spatial autocorrelation can differ among age classes, our study indicates that fluctuations in age structure can influence the spatio-temporal variation in abundance of marine fish populations.publishedVersio

Spatial scaling of population synchrony in marine fish depends on their life history

The synchrony of population dynamics in space has important implications for ecological processes, for example affecting the spread of diseases, spatial distributions and risk of extinction. Here, we studied the relationship between spatial scaling in population dynamics and species position along the slow‐fast continuum of life history variation. Specifically, we explored how generation time, growth rate and mortality rate predicted the spatial scaling of abundance and yearly changes in abundance of eight marine fish species. Our results show that population dynamics of species' with ‘slow’ life histories are synchronised over greater distances than those of species with ‘fast’ life histories. These findings provide evidence for a relationship between the position of the species along the life history continuum and population dynamics in space, showing that the spatial distribution of abundance may be related to life history characteristics.acceptedVersio

ACCELERATED LEARNING BERBANTUAN SOFTWARE MAPLE SEBAGAI UPAYA MENINGKATKAN KEMAMPUAN KOMUNIKASI MATEMATIS DAN MINAT BELAJAR SISWA SMA

Penelitian ini dilatarbelakangi oleh pentingnya kemampuan komunikasi matematis dan minat belajar. Namun kenyataan di lapangan menunjukkan bahwa kemampuan komunikasi matematisdan minat belajarsiswa masih rendah. Agar permasalahan tersebut dapat diatasi, diperlukan sebuah model pembelajaran yang dapatmeningkatkankemampuan komunikasi matematis dan minat belajarsiswa.Olehkarenaitu, dipilih modelAccelerated Learning Berbantuan Software Maple. Penelitian ini bertujuan untuk menelaahpeningkatan kemampuan komunikasi matematis dan minat belajarsiswa, danmenelaahhubunganantara kemampuan komunikasi dan minat belajar.Penelitianinimerupakanpenelitiankuasieksperimendenganpretest-postest control group design. Populasi pada penelitian ini adalah seluruh siswa kelas X pada salah satu SMA Negeri di Kota Purwokerto. Sampel terdiri dari dua kelas yang dipilih secara purposive sampling.Instrumen yang digunakan berupa tes kemampuan komunikasi matematis dan angket minat belajar, lembar observasi, serta pedoman wawancara. Analisis data dilakukan secara kuantitatif.Analisis data tersebutmenggunakanMann-Whitney U Testdan uji asosiasi Chi Square. Berdasarkan analisis data, ditemukan bahwa: (1)pencapaian kemampuan komunikasi matematis siswa yang memperoleh Accelerated LearningBerbantuanSoftware Maplelebih baik daripada siswa yang memperoleh pembelajaran biasa;(2) peningkatan kemampuan komunikasi matematis siswa yang memperoleh Accelerated LearningBerbantuanSoftware Maplelebih baik daripada siswa yang memperoleh pembelajaran biasa, (3) pencapaian kemampuan minat belajar siswa yang memperoleh Accelerated LearningBerbantuanSoftware Maplelebih baik daripada siswa yang memperoleh pembelajaran biasa; (4) peningkatan kemampuan minat belajar siswa yang memperoleh Accelerated LearningBerbantuanSoftware Maplelebih baik daripada siswa yang memperoleh pembelajaran biasa; dan(5) terdapat asosiasi antara kemampuan komunikasi dan minat belajarsiswadengan kategori rendah. ---------- This research was motivated by the importance of mathematical communication learning interest of students. Mathematical communication ability and learning interest of students is still low. In order that this problemscan be solved, alearning modelthatcan enhancemathematical communication and learning interest ofstudents is required.In this research, Maple-Assisted Accelerated Learning was selected. This studyaims to analyzetheenhancement of mathematical communication learning interest of students, and to analyzetheassociationbetween mathematical communication ability andlearning interest of students. This research was aquasi-experimentalwithpretest-posttest control group design. The population was students at tenth gradein one of senior high schools in Purwokerto, Central Java. The sample consisted oftwoclasses which wasselected bypurposivesampling. This research used fourinstruments: testof mathematicalcommunication ability, learning interestquestionnaire, observation sheets, and interview guide.Data analyzed was done quantitatively. The data were analyzed by usingMann-Whitney U TestandChi Squaren test. Based on the data analyze, it is found that: (1) the achievement of mathematical communication ability of students who receivedthe Maple-Assisted Accelerated Learning is betterthan the achievement of students who receivedconventionallearning;(2) The enhancement of mathematical communication ability of students who receivedthe Maple-Assisted Accelerated Learning is betterthan the enhancement of students who receivedconventionallearning; (3)the achievement oflearning interestability of students who receivedthe Maple-Assisted Accelerated Learning is betterthan the achievement of students who receivedconventionallearning; (4)the enhancement oflearning interestof students who receivedthe Maple-Assisted Accelerated Learning is betterthan the enhancement of students who receivedconventionallearning; and(5) there is anassociation between students’ mathematical communication ability and learning interest of student

Controlling for P-value inflation in allele frequency change in experimental evolution and artificial selection experiments

acceptedVersio

Long‐distance dispersal in the short‐distance dispersing house sparrow ( Passer domesticus )

The house sparrow (Passer domesticus) is a small passerine known to be highly sedentary. Throughout a 30‐year capture–mark–recapture study, we have obtained occasional reports of recoveries far outside our main metapopulation study system, documenting unusually long dispersal distances. Our records constitute the highest occurrence of long‐distance dispersal events recorded for this species in Scandinavia. Such long‐distance dispersals radically change the predicted distribution of dispersal distances and connectedness for our study metapopulation. Moreover, it reveals a much greater potential for colonization than formerly recorded for the house sparrow, which is an invasive species across four continents. These rare and occasional long‐distance dispersal events are challenging to document but may have important implications for the genetic composition of small and isolated populations and for our understanding of dispersal ecology and evolution

Genetic architecture and heritability of early‐life telomere length in a wild passerine

Early-life telomere length (TL) is associated with fitness in a range of organisms. Little is known about the genetic basis of variation in TL in wild animal populations, but to understand the evolutionary and ecological significance of TL it is important to quantify the relative importance of genetic and environmental variation in TL. In this study, we measured TL in 2746 house sparrow nestlings sampled across 20 years and used an animal model to show that there is a small heritable component of early-life TL (h2maternal = 0.04). Variation in TL among individuals was mainly driven by environmental (annual) variance, but also brood and parental effects. Parent-offspring regressions showed a large maternal inheritance component in TL (h2maternal=0.44), but no paternal inheritance. We did not find evidence for a negative genetic correlation underlying the observed negative phenotypic correlation between TL and structural body size. Thus, TL may evolve independently of body size and the negative phenotypic correlation is likely to be caused by non-genetic environmental effects. We further used genome-wide association analysis to identify genomic regions associated with TL variation. We identified several putative genes underlying TL variation; these have been inferred to be involved in oxidative stress, cellular growth, skeletal development, cell differentiation and tumorigenesis in other species. Together, our results show that TL has a low heritability and is a polygenic trait strongly affected by environmental conditions in a free-living bird