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Most theoretical models on evolution of male secondary sexual characters and female preferences for these characters suggest that the male characters evolve in response to female preferences that may themselves evolve in response to direct or indirect benefits of choice. In Drosophila montana (a species of the D. virilis group), females use male song in(More)
We have used a quantitative trait locus (QTL) mapping approach to study the genetic basis of differences between two Drosophila virilis strains representing extreme phenotypes in two song characters, the number of pulses in a pulse train (PN) and the length of a pulse train (PTL). Variation in these characters among 520 F2 males was studied by single-marker(More)
Conspicuous cyclic changes in population density characterize many populations of small northern rodents. The extreme crashes in individual number are expected to reduce the amount of genetic variation within a population during the crash phases of the population cycle. By long-term monitoring of a bank vole (Myodes glareolus) population, we show that(More)
Many western European carnivore populations became almost or completely eradicated during the last ~200 years, but are now recovering. Extirpation of wolves started in Finland in the 19th century, and for more than 150 years the population size of wolves has remained small. To investigate historical patterns of genetic variation, we extracted DNA from 114(More)
In Drosophila montana, male courtship song frequency is closely associated with male courtship success and offspring survival. Other pulse characters (pulse length and cycle number) may also affect female mate choice, whereas pulse train characters (interpulse interval, pulse number and pulse train length) are not associated with these male fitness(More)
This study partitions selection in a natural metapopulation of a riparian plant species, Silene tatarica, into individual- and patch-level components by using contextual analysis, in which a patch refers to a spatially distinct stand of individual plants. We estimated selection gradients for two morphological characters (plant height and number of stems),(More)
The males of six species of the Drosophila virilis group (including D. virilis) keep their wings extended while producing a train of sound pulses, where the pulses follow each other without any pause. The males of the remaining five species of the group produce only one sound pulse during each wing extension/vibration, which results in species-specific(More)
We estimated heritabilities for several male courtship song characters in two Drosophila species using father-son regression under conditions where both fathers and sons had been raised in the laboratory. In D. montana the heritabilities of song characters were rather high (-0.23 to 0.80) and in most cases significant. In D. littoralis the heritabilities of(More)
Loss of connectivity and habitat destruction may lead to genetic depletion of wild animal populations, especially in species requiring large, connected territories as the brown bear (Ursus arctos). Brown bear populations of North Western Russia, Finland and Northern Norway have been assumed to form one large, continuous population; however this hypothesis(More)
Killing conspecific infants (infanticide) is among the most puzzling phenomena in nature. Stable polymorphism in such behaviour could be maintained by negative frequency-dependent selection (benefit of rare types). However, it is currently unknown whether there is genetic polymorphism in infanticidal behaviour or whether infanticide may have any fitness(More)