A selection for sperm quality was carried out in the White Plymouth Rock population of the Spelderholt institute. The percentage of morphologically abnormal spermatozoa was used as the most important selection criterion. The population was selected in two directions, viz. a line with a low incidence (Ll-line) of abnormal spermatozoa and a line with a high incidence (Hl-line). Cocks were examine...

Recent years have seen increasing interest in indirect genetic effects, i.e. influences on the phenotype that depend on the genotype of other conspecific individuals; however, the empirical evidence for such effects is still limited, especially in wild plant species. The present study of the clonal herb Sedum album assessed direct and indirect genetic effects on performance-related traits in a ...

The forces driving the evolution of extra-pair reproduction in socially monogamous animals remain widely debated and unresolved. One key hypothesis is that female extra-pair reproduction evolves through indirect genetic benefits, reflecting increased additive genetic value of extra-pair offspring. Such evolution requires that a female's propensity to produce offspring that are sired by an extra...

For the first time, a screening procedure for antitumor monoclonal antibodies (MOABs) has been developed in which the ability of MOABs to mediate the indirect action of another immunotoxin is the primary criterion for selection of hybridomas for expansion and cloning. Use of the indirect immunotoxin makes it possible to screen MOABs for cytotoxic potential without the necessity of covalently co...

Female mating preferences are often flexible, reflecting the social environment in which they are expressed. Associated indirect genetic effects (IGEs) can affect the rate and direction of evolutionary change, but sexual selection models do not capture these dynamics. We incorporate IGEs into quantitative genetic models to explore how variation in social environments and mate choice flexibility...

Action selection often requires the transformation of visual information into motor plans. Preventing premature responses may entail the suppression of visual input and/or of prepared muscle activity. This study examined how the quality of visual information affects frontobasal ganglia (BG) routes associated with response selection and inhibition. Human fMRI data were collected from a stop task...

Threespine sticklebacks, small fish with a circumglobal distribution in coastal marine and freshwater of the northern hemisphere, present a remarkable scope of variation in body and fin shape among populations. The repeated evolution of divergent body shapes in a radiation of stickleback from Cook Inlet, Alaska suggests that diversification has proceeded by extensive parallel selection. To expl...

Background: Theoretical studies suggest that direct and indirect selection have the potential to cause substantial evolutionary change in female mate choice. Similarly, sexual selection is considered a strong force in the evolution of male attractiveness and the exaggeration of secondary sexual traits. Few studies have, however, directly tested how female mate choice and male attractiveness res...

Crop yield in dry environments can be improved with complementary approaches including selecting for yield in the target environments, selecting for yield potential, and using indirect, trait- or genomic-based methods. This paper (i) outlines the achievements of direct selection for yield in improving drought adaptation, (ii) discusses the limitations of indirect approaches in the context of le...

Most theoretical research in sexual selection has focused on indirect selection. However, empirical studies have not strongly supported indirect selection. A well-established finding is that direct benefits and costs exert a strong influence on the evolution of mate choice. We present an analytical model in which unilateral mate choice evolves solely by direct sexual selection on choosiness. We...