Search results for "sukusiitos"
showing 10 items of 10 documents
Viability selection creates negative heterozygosity–fitness correlations in female Black Grouse Lyrurus tetrix
2017
There is widespread interest in the relationship between individual genetic diversity and fitness–related traits (heterozygosity–fitness correlations, HFC). Most studies found weak continuous increases of fitness with increasing heterozygosity while negative HFC have rarely been reported. Negative HFC are expected in cases of outbreeding depression and outbreeding is rare in natural populations; but negative HFC may also arise through viability selection acting on low heterozygosity individuals at an early stage producing a skew in the heterozygosity distribution leading to negative HFCs. We tested this idea using survival and clutch parameters (egg mass, egg volume, chick mass, clutch size…
Starvation resistance and tissue-specific gene expression of stress-related genes in a naturally inbred ant population
2016
Starvation is one of the most common and severe stressors in nature. Not only does it lead to death if not alleviated, it also forces the starved individual to allocate resources only to the most essential processes. This creates energetic trade-offs which can lead to many secondary challenges for the individual. These energetic trade-offs could be exacerbated in inbred individuals, which have been suggested to have a less efficient metabolism. Here, we studied the effect of inbreeding on starvation resistance in a natural population of Formica exsecta ants, with a focus on survival and tissue-specific expression of stress, metabolism and immunity-related genes. Starvation led to large tis…
Inbreeding does not alter the response to an experimental heat wave in a freshwater snail
2019
Global climate change affects natural populations of many species by increasing the average temperature and the frequency of extreme weather events (e.g. summer heat waves). The ability of organisms to cope with these environmental changes can, however, depend on their genetic properties. For instance, genetic load owing to inbreeding could alter organisms’ responses to climate change-mediated environmental changes but such effects are often overlooked. We investigated the effects of an experimental heat wave (25°C versus 15°C) on life history (reproduction, size) and constitutive immune defence traits (phenoloxidase-like and antibacterial activity of haemolymph) in relation to inbreeding b…
The Demographic Costs of Sexually Antagonistic Selection in Partially Selfing Populations
2022
When selection differs between the sexes, genes expressed by both males and females can experience sexually antagonistic (SA) selection, where beneficial alleles for one sex are deleterious for the other. Classic population genetics theory has been fundamental to understanding how and when SA genetic variation can be maintained by balancing selection, but these models have rarely considered the demographic consequences of coexisting alleles with deleterious fitness effects in each sex. In this article, we develop a stage-structured Mendelian matrix model and jointly analyze the evolutionary and demographic consequences of SA selection in obligately outcrossing (i.e., dioecious/gonochorous) …
Interactions and patterns between species diversity and genetic diversity
2015
Opposing health effects of hybridization for conservation
2021
The continuing decline of many natural plant and animal populations emphasizes the importance of conservation strategies. Hybridization as a management tool has proven successful in introducing gene flow to small, inbred populations, but can be also associated with health risks. For example, hybridization can change susceptibility to infection in either direction due to heterosis (hybrid vigor) and outbreeding depression, but such health effects have rarely been considered in the genetic management of populations. Here, we investigated the effects of experimental outcrossing between the critically endangered Saimaa landlocked salmon (Salmo salar m. sebago) and the genetically more diverse A…
Heterozygosity-fitness correlations and the maintenance of genetic variation in small populations in Drosophila littoralis
2010
Fitness and viability of small populations : the effects of genetic drift, inbreeding, and interpopulation hybridization
2012
The effects of inbreeding on mating success and offspring production of males and females in a Drosophila littoralis population
2011
Sisäsiitoksella, eli pariutumisella lähisukulaisten kesken, on monia negatiivisia vaikutuksia sekä populaation että yksilön kelpoisuudelle. Sisäsiitos lisää homotsygotiaa ja mahdollistaa siten väistyvien haitallisten mutaatioiden ilmentymisen fenotyypissä sekä estää heterotsygotiasta johtuvaa paremmuutta lokuksissa, joissa on ylidominanssia. On osoitettu, että sisäsiittoisuus voi vaikuttaa koiraisiin ja naaraisiin eri tavalla siten, että toinen sukupuolista kärsii sisäsiitoksesta toista enemmän. Jotkut tutkimukset ovat näyttäneet, että sisäsiittoisuudella on voimakkaampi negatiivinen vaikutus koiraiden kuin naaraiden lisääntymiskykyyn, kun taas toiset osoittavat että naaraat kärsivät enemmä…