Voidaanko metsien biologisen monimuotoisuuden väheneminen pysäyttää vuoteen 2020 mennessä? Huomioita metsälakiesityksestä

Tieteen tori: Metsälakiuudistu

Evoluution todisteet

Richard Dawkins: Maailmanhienoin esitys. Evoluution todisteet. Suomentanut Kimmo Pietiläinen, Terra Cognita 2009

Elämän tulevaisuus on turvattu – mutta minkälaisen elämän?

Edward O. Wilson: Elämän tulevaisuus. Suomentanut Kimmo Pietiläinen, Terra Cognita Oy, Helsinki 2002. 222 s

Vastauksia Erkki Annilalle, Veli-Pekka Järveläiselle, Matti Keltikankaalle ja Seppo Vehkamäelle

Metsätaloutta ei voida kutsua ekologisesti kestäväksi, jos se uhkaa tuhannen eliölajin esiintymistä Suomessa ja kaventaa tulevien sukupolvien mahdollisuutta päättää itse oman metsäsuhteensa luonteesta

Natural history of some Siberian melitaeine butterfly species (Nymphalidae: Melitaeini) and their parasitoids

We report observations on the larval gregarious behaviour, host plant use and parasitoids of six species of melitaeine butterfly in the Russian Republic of Buryatia. We observed post-diapause larvae in two habitats, steppe and taiga forest region. Five species were found in the steppe region: Euphydryas aurinia davidi, Melitaea cinxia, M. latonigena, M. didymoides and M. phoebe. Three species (M. cinxia, M. latonigena and M. didymoides) fed on the same host plant, Veronica incana (Plantaginaceae). Euphydryas aurinia larvae were found on Scabiosa comosa (Dipsacaceae) and M. phoebe larvae on Stemmacantha uniflora (Asteraceae). Three species were found in the taiga region (M. cinxia, M. latonigena and M. centralasiae), of which the first two fed on Veronica incana. Five species of hymenopteran parasitoids and three species of dipteran parasitoids were reared from the butterfly larvae of five species

Conditional reproductive strategies under variable environmental conditions

Within the framework of adaptive dynamics we consider the evolution by natural selection of reproductive strategies in which individuals may adjust their reproductive behaviour in response to changing environmental conditions. As a specific example we considered a discrete-time model in which possible fluctuations in the environmental conditions are caused by predator-prey interaction. Our main findings include: (1) Coexistence between two fixed strategies (i.e., strategies that do not adjust to changing environmental conditions) is impossible; there exists a best fixed strategy, which invades and ousts all other fixed strategies. (2) A necessary condition for conditional (adjustable) strategies to evolve is that there are fluctuations in the environmental conditions. Predator-prey interactions may cause such fluctuations and under natural assumptions there exists an optimal conditional strategy which is uninvadable and invades and ousts all other strategies.Peer reviewe

Variation in a host–parasitoid interaction across independent populations

Abstract: Antagonistic relationships between parasitoids and their insect hosts involve multiple traits and are shaped by their ecological and evolutionary context. The parasitoid wasp Cotesia melitaearum and its host butterfly Melitaea cinxia occur in several locations around the Baltic sea, with differences in landscape structure, population sizes and the histories of the populations. We compared the virulence of the parasitoid and the susceptibility of the host from five populations in a reciprocal transplant-style experiment using the progeny of five independent host and parasitoid individuals from each population. The host populations showed significant differences in the rate of encapsulation and parasitoid development rate. The parasitoid populations differed in brood size, development rate, pupal size and adult longevity. Some trait differences depended on specific host-parasitoid combinations, but neither species performed systematically better or worse in experiments involving local versus non-local populations of the other species. Furthermore, individuals from host populations with the most recent common ancestry did not perform alike, and there was no negative effect due to a history of inbreeding in the parasitoid. The complex pattern of variation in the traits related to the vulnerability of the host and the ability of the parasitoid to exploit the host may reflect multiple functions of the traits that would hinder simple local adaptation.Peer reviewe

Significant effects of Pgi genotype and body reserves on lifespan in the Glanville fritillary butterfly

Individuals with a particular variant of the gene phosphoglucose isomerase (Pgi ) have been shown to have superior dispersal capacity and fecundity in the Glanville fritillary butterfly (Melitaea cinxia), raising questions about the mechanisms that maintain polymorphism in this gene in the field. Here, we investigate how variation in the Pgi genotype affects female and male life history under controlled conditions. The most striking effect is the longer lifespan of genotypes with high dispersal capacity, especially in nonreproducing females. Butterflies use body reserves for somatic maintenance and reproduction, but different resources (in thorax versus abdomen) are used under dissimilar conditions, with some interactions with the Pgi genotype. These results indicate life-history trade-offs that involve resource allocation and genotype!environment interactions, and these trade-offs are likely to contribute to the maintenance of Pgi polymorphism in the natural populations.Non Peer reviewe

SNP discovery by mismatch-targeting of Mu transposition

Single nucleotide polymorphisms (SNPs) represent a valuable resource for the mapping of human disease genes and induced mutations in model organisms. SNPs may become the markers of choice also for population ecology and evolutionary studies, but their isolation for non-model organisms with unsequenced genomes is often difficult. Here, we describe a rapid and cost-effective strategy to isolate SNPs that exploits the property of the bacteriophage Mu transposition machinery to target mismatched DNA sites and thereby to effectively detect polymorphic loci. To demonstrate the methodology, we isolated 164 SNPs from the unsequenced genome of the Glanville fritillary butterfly (Melitaea cinxia), a much-studied species in population biology, and we validated 24 of them. The strategy involves standard molecular biology techniques as well as undemanding MuA transposase-catalyzed in vitro transposition reactions, and it is applicable to any organism