Search results for "poikueet"
showing 3 items of 3 documents
Can number and size of offspring increase simultaneously? – A central life-history trade-off reconsidered
2012
Background: To maximize their fitness, parents are assumed to allocate their resources optimally between number and size of offspring. Although this fundamental life-history trade-off has been subject to long standing interest, its genetic basis, especially in wild mammals, still remains unresolved. One important reason for this problem is that a large multigenerational pedigree is required to conduct a reliable analysis of this trade-off. Results: We used the REML-animal model to estimate genetic parameters for litter size and individual birth size for a common Palearctic small mammal, the bank vole (Myodes glareolus). Even though a phenotypic trade-off between offspring number and size wa…
Cost of reproduction and offspring quality in the evolution of reproductive effort
2002
Any organism has a limited amount of resources, which have to be partitioned among several activities such as maintenance, growth and reproduction. Reproductive effort is defined as the proportion of parental resources devoted to fecundity and offspring survival. The extent of reproductive effort is restricted by trade-offs that cancel out the advantages of increasing investment in reproduction. This thesis presents an investigation into the determinants of reproductive effort in the bank vole, Clethrionomys glareolus, focusing mainly on two major life history trade-offs i.e. cost of reproduction and trade-off between offspring number and quality. Insights into other potentially important p…
Evolutionary trade-offs in a small mammal : a quantitative genetics approach
2017
Limited resources force individuals to trade-off between life-history traits. A vast diversity of life-history strategies, which optimally combine life history traits, can be found. Knowledge of the genetic basis of this phenotypic variation is key to understanding evolutionary processes. I approached life-history evolution by estimating quantitative genetic parameters for a set of life-history traits in the bank vole (Myodes glareolus). The work is based on a laboratory-kept colony subjected to two-way selection for litter size (High- (H) and Low- (L) lines). Costs of the created reproductive strategies were observed in natural conditions. Selection increased the difference in litter size …