The Japanese quail has been utilized as a research species in establishing the genetic relationships that may also be present in other species. Divergent phenotypic selection for 4-wk BW was conducted for three generations in high (HW) and low (LW) lines. Within each line, 50 females and 25 males were selected among 600 birds, based on 4-wk BW. Mean BW at 4 wk of age in the base generation was ...

The Breeder Genetic Algorithm (BGA) was designed according to the theories and methods used in the science of livestock breeding. The prediction of a breeding experiment is based on the response to selection (RS) equation. This equation relates the change in a population's fitness to the standard deviation of its fitness, as well as to the parameters selection intensity and realized heritabilit...

Allocation to sexual reproduction is an important life-history trait in clonal plants. Different selection pressures between competitive and competition-free environments are likely to result in the evolution of specialized genotypes and to maintain genetic variation in reproductive allocation. Moreover, selection may also result in the evolution of plastic allocation strategies. The necessary ...

Directional selection produces a change in the population mean of a phenotype, but this shift will only be translated into a phenotypic difference between generations if the trait is heritable, in the sense that there is additive genetic variance in the trait. Thus any study of evolutionary change must concern itself both with the factors causing phenotypic change and the genetic architecture o...

The potential of populations to evolve in response to ongoing climate change is partly conditioned by the presence of heritable genetic variation in relevant physiological traits. Recent research suggests that Drosophila melanogaster exhibits negligible heritability, hence little evolutionary potential in heat tolerance when measured under slow heating rates that presumably mimic conditions in ...

Response to divergent selection for “high” and “low” survival during the summer period, from July to October, was investigated in juvenile (six-month-old) Pacific oysters, Crassostrea gigas, by producing two sets of progenies in 2002 (Generation 2) and three sets of progenies in 2003 (Generation 3). A strict between-family approach was used and resistance of these selected progenies to summer m...