Search results for "geneettinen"

The relationship between genetic diversity of an annelid worm, Pygospio elegans, and local invertebrate species diversity

2016

Ympäristön monimuotoisuutta mitataan pääasiassa erilaisten biologisten yksiköiden lukumäärinä. Populaatiogenetiikassa ne ovat geenejä tai alleeleja yhden lajin sisällä, yhteisöekologiassa puolestaan lajeja eliöyhteisöjen sisällä. Molemmat näistä monimuotoisuuden tasoista – lajin sisäinen ja lajien välinen monimuotoisuus – muokkautuvat ekologisten ja evolutiivisten prosessien kautta, jotka puolestaan syntyvät ympäristön olosuhteista. Ympäristön ominaisuuksien ja niistä syntyvien prosessien tiedetään vaikuttavan molempiin monimuotoisuuden tasoihin samankaltaisesti: tämän teorian mukaan niiden välillä tulisi siten löytyä positiivinen korrelaatio. Tässä tutkimuksessa pyrin etsimään laajalti huo…

Maintenance of genetic diversity in cyclic populations - a longitudinal analysis in Myodes glareolus

2012

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 despite the substantial and repetitive crashes in the population size, high heterozygosity is maintained throughout the population cycle. The striking population density fluctuation in fact only slightly reduced the allelic richness of the population during the crash phases. Effective population sizes of vole populations remained also relativel…

Evolution of hermaphroditic mating systems in animals

2004

Miksi jotkin eläinlajit ovat kaksineuvoisia ja toisissa lajeissa koiras- ja naarasominaisuudet ovat eri yksilöissä? Kaksineuvoiset eläimet pystyvät lisääntymään itsesiitoksella ilman kumppania tai ristisiitoksella kumppanin kanssa. Kumpi lisääntymistapa on parempi? Muun muassa näitä kysymyksiä väitöskirjassaan pohtinut Mikael Puurtinen loi tutkimuksessaan teoriaa lisääntymistapojen evoluutiosta, sekä selvitti vedessä elävän isolimakotilon (Lymnaea stagnalis) lisääntymisbiologiaa. Suomen Akatemian nimittämässä evoluutioekologian huippuyksikössä tehty tutkimus toi arvokasta tietoa populaation geneettisen monimuotoisuuden vaikutuksista populaation elinkykyyn sekä kykyyn vastustaa loistauteja. …

Selection on two behavioral genes : fitness effects of receptor genes for arginine vasopressin 1a and oxytocin in the bank vole Myodes glareolus

2017

Most variation in behavior is regulated by genes; nevertheless the mechanisms behind maintenance of genetic diversity at behavioral loci have remained mainly elusive in natural populations. I studied in my thesis selection mechanisms of two genes associated with socio-sexual behavior, arginine vasopressin receptor 1a (Avpr1) and oxytocin receptor (Oxtr) in bank vole (Myodes glareolus). Expression of Avpr1a and Oxtr in specific regions of the brain regulates diverse social and reproductive behaviors such as parental care, aggression, sexual behavior, social recognition as well as pair and parent- offspring bonding in mammals. In addition, there is a link between the length of a regulatory re…

Fitness and viability of small populations : the effects of genetic drift, inbreeding, and interpopulation hybridization

2012

Early life of fathers affects offspring fitness in a wild rodent

2019

Intergenerational fitness effects on offspring due to the early life of the parent are well studied from the standpoint of the maternal environment, but intergenerational effects owing to the paternal early life environment are often overlooked. Nonetheless, recent laboratory studies in mammals and ecologically relevant studies in invertebrates predict that paternal effects can have a major impact on the offspring's phenotype. These non‐genetic, environment‐dependent paternal effects provide a mechanism for fathers to transmit environmental information to their offspring, and could allow rapid adaptation. We used the bank vole Myodes glareolus, a wild rodent species with no paternal care, t…

Implications of heat waves on immune defence, life history traits, and adaptive potential : a snail's perspective

2014

Range expansion to novel environments : evolutionary physiology and genetics in Leptinotarsa decemlineata

2010

Seasonal variation in diversity of marine benthic invertebrates leads to a positive species-genetic diversity correlation (SGDC)

2018

Species-genetic diversity correlations (SGDCs) are useful indicators of processes that simultaneously affect diversity at multiple biological levels. We combined spatial and temporal sampling of 4 study sites in the Danish Isefjord-Roskilde Fjord Estuary at 4 time points over 1 yr to investigate the effect of seasonal variation on SGDCs. Species diversity was estimated as species richness from samples comprising 20752 individuals representing 51 benthic invertebrate taxa. Genetic diversity was estimated for a single focal taxon, the polychaete Pygospio elegans, as mean allelic richness at 7 microsatellite loci. Combining all samples, a significant positive correlation between species richne…

Colour alone matters : no predator generalization among morphs of an aposematic moth

2018

Local warning colour polymorphism, frequently observed in aposematic organisms, is evolutionarily puzzling. This is because variation in aposematic signals is expected to be selected against due to predators' difficulties associating several signals with a given unprofitable prey. One possible explanation for the existence of such variation is predator generalization, which occurs when predators learn to avoid one form and consequently avoid other sufficiently similar forms, relaxing selection for monomorphic signals. We tested this hypothesis by exposing the three different colour morphs of the aposematic wood tiger moth, Arctia plantaginis, existing in Finland to local wild-caught predato…