BACKGROUND/AIM Bipolar affective disorder is mental disorder with polygenic type of heredity. Heritability--relation between genetic and environmental variance is used to estimate the level of influence of genetic variance to phenotype variance. Study results show decreasing trend in the value of heritability of bipolar affective disorder, thus indicating that this disorder is a complex behavio...

Environmental variance components were estimated for berry ripening time (BRT), berry weight (BW), soluble solids concentration (SSC), titratable acidity (TA), and deformation at the ®rst major peak (DFP) and maximum force (MF) in penetration tests of berry ̄esh in grapes (Vitis vinifera L. and V. labruscana Bailey). The variance among berries within clusters was largest among environmental var...

random regression models (rrm) have become common for the analysis of longitudinal data or repeated records on individual over time. the goal of this paper was to explore the use of random regression models with orthogonal / legendre polynomials (rrl) to analyze new repeated measures called clutch size (cs) as a meristic trait for iranian native fowl. legendre polynomial functions of increasing...

PURPOSE Twin studies have demonstrated a high heritability for refractive error of up to 90%, but some family studies have suggested up to one-third of population variance is attributable to the effects of shared family environment. This large twin study aimed to explore the role of shared environment in refractive error. METHODS Refractive error was measured using autorefraction in 4602 subj...

Food intake is an essential animal activity, regulated by neural circuits that motivate food localization, evaluate nutritional content and acceptance or rejection responses through the gustatory system, and regulate neuroendocrine feedback loops that maintain energy homeostasis. Excess food consumption in people is associated with obesity and metabolic and cardiovascular disorders. However, li...

A cornerstone of evolutionary theory is that the phenotypic variance of a population may be partitioned into genetic and environmental (nonheritable) components. The traditional motivation for this distinction is that the rate of evolution under natural selection depends on the (relative) magnitudes of certain genetic components of variance. The components of variation are also interesting from...

Phenotypic variation within populations has two sources: genetic variation and environmental variation. Here, we investigate the coevolution of these two components under fluctuating selection. Our analysis is based on the lottery model in which genetic polymorphism can be maintained by negative frequency-dependent selection, whereas environmental variation can be favored due to bet-hedging. In...

The spatial distribution of a natural resource is an important consideration in designing an efficient survey or monitoring program for the resource. We review a unified strategy for designing probability samples of discrete, finite resource populations, such as lakes within some geographical region; linear populations, such as a stream network in a drainage basin; and continuous, two-dimension...

Neutral models and differential responses of species to environmental heterogeneity offer complementary explanations of species abundance distribution and dynamics. Under what circumstances one model prevails over the other is still a matter of debate. We show that the decay of similarity over time in rocky seashore assemblages of algae and invertebrates sampled over a period of 16 years was co...