6 research outputs found

    Velocity of density shifts in Finnish landbird species depends on their migration ecology and body mass

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    A multitude of studies confirm that species have changed their distribution ranges towards higher elevations and towards the poles, as has been predicted by climate change forecasts. However, there is large interspecific variation in the velocity of range shifts. From a conservation perspective, it is important to understand which factors explain variation in the speed and the extent of range shifts, as these might be related to the species' extinction risk. Here, we study shifts in the mean latitude of occurrence, as weighted by population density, in different groups of landbirds using 40 years of line transect data from Finland. Our results show that the velocity of such density shifts differed among migration strategies and increased with decreasing body size of species, while breeding habitat had no influence. The slower velocity of large species could be related to their longer generation time and lower per capita reproduction that can decrease the dispersal ability compared to smaller species. In contrast to some earlier studies of range margin shifts, resident birds and partial migrants showed faster range shifts, while fully migratory species were moving more slowly. The results suggest that migratory species, especially long-distance migrants, which often show decreasing population trends, might also have problems in adjusting their distribution ranges to keep pace with global warming.Peer reviewe

    Evidence for sex-specific selection in brain: a case study of the nine-spined stickleback

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    Theory predicts that the sex making greater investments into reproductive behaviours demands higher cognitive ability, and as a consequence, larger brains or brain parts. Further, the resulting sexual dimorphism can differ between populations adapted to different environments, or among individuals developing under different environmental conditions. In the nine-spine stickleback (Pungitius pungitius), males perform nest building, courtship, territory defence and parental care, whereas females perform mate choice and produce eggs. Also, predation-adapted marine and competition-adapted pond populations have diverged in a series of ecologically relevant traits, including the level of phenotypic plasticity. Here, we studied sexual dimorphism in brain size and architecture in nine-spined stickleback from marine and pond populations reared in a factorial experiment with predation and food treatments in a common garden experiment. Males had relatively larger brains, larger telencephala, cerebella and hypothalami (6–16% divergence) than females, irrespective of habitat. Females tended to have larger bulbi olfactorii than males (13%) in the high food treatment, whereas no such difference was found in the low food treatment. The strong sexual dimorphism in brain architecture implies that the different reproductive allocation strategies (behaviour vs. egg production) select for different investments into the costly brains between males and females. The lack of habitat dependence in brain sexual dimorphism suggests that the sex-specific selection forces on brains differ only negligibly between habitats. Although significance of the observed sex-specific brain plasticity in the size of bulbus olfactorius remains unclear, it demonstrates the potential for sex-specific neural plasticity

    Evidence for sex-specific selection in brain: a case study of the nine-spined stickleback.

    No full text
    Theory predicts that the sex making greater investments into reproductive behaviours demands higher cognitive ability, and as a consequence, larger brains or brain parts. Further, the resulting sexual dimorphism can differ between populations adapted to different environments, or among individuals developing under different environmental conditions. In the nine-spine stickleback (Pungitius pungitius), males perform nest building, courtship, territory defence and parental care, whereas females perform mate choice and produce eggs. Also, predation-adapted marine and competition-adapted pond populations have diverged in a series of ecologically relevant traits, including the level of phenotypic plasticity. Here, we studied sexual dimorphism in brain size and architecture in nine-spined stickleback from marine and pond populations reared in a factorial experiment with predation and food treatments in a common garden experiment. Males had relatively larger brains, larger telencephala, cerebella and hypothalami (6–16% divergence) than females, irrespective of habitat. Females tended to have larger bulbi olfactorii than males (13%) in the high food treatment, whereas no such difference was found in the low food treatment. The strong sexual dimorphism in brain architecture implies that the different reproductive allocation strategies (behaviour vs. egg production) select for different investments into the costly brains between males and females. The lack of habitat dependence in brain sexual dimorphism suggests that the sex-specific selection forces on brains differ only negligibly between habitats. Although significance of the observed sex-specific brain plasticity in the size of bulbus olfactorius remains unclear, it demonstrates the potential for sex-specific neural plasticity

    Genome-wide association study and meta-analysis in Northern European populations replicate multiple colorectal cancer risk loci

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    Genome-wide association studies have been successful in elucidating the genetic basis of colorectal cancer (CRC), but there remains unexplained variability in genetic risk. To identify new risk variants and to confirm reported associations, we conducted a genome-wide association study in 1,701 CRC cases and 14,082 cancer-free controls from the Finnish population. A total of 9,068,015 genetic variants were imputed and tested, and 30 promising variants were studied in additional 11,647 cases and 12,356 controls of European ancestry. The previously reported association between the single-nucleotide polymorphism (SNP) rs992157 (2q35) and CRC was independently replicated (p=2.08 x 10(-4); OR, 1.14; 95% CI, 1.06-1.23), and it was genome-wide significant in combined analysis (p=1.50 x 10(-9); OR, 1.12; 95% CI, 1.08-1.16). Variants at 2q35, 6p21.2, 8q23.3, 8q24.21, 10q22.3, 10q24.2, 11q13.4, 11q23.1, 14q22.2, 15q13.3, 18q21.1, 20p12.3 and 20q13.33 were associated with CRC in the Finnish population (false discovery ratePeer reviewe

    Evidence of a causal effect of genetic tendency to gain muscle mass on uterine leiomyomata

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