Beyond Alleles: Quantitative Genetics and the Evolution of Phenotypes

Flashcards covering key terms and concepts related to polygenic traits, quantitative genetics, heritability, variance, and estimation methods.

Polygenic Traits

Traits influenced by many genetic loci and may vary continuously among individuals (e.g., human height).

Quantitative Genetics

The study of the genetic mechanisms and evolution of continuous phenotypic traits.

Variance

A statistical measure of the dispersion of trait values about their mean.

Broad Sense Heritability (H2)

The proportion of total phenotypic variation of a trait attributable to genetic differences among individuals.

Narrow Sense Heritability

Proportion of phenotypic variance explained by the additive effects of alleles.

Epistasis

Interaction between alleles at different loci affecting polygenic traits.

Environmental Variation (VE)

Variance in phenotypic traits due to environmental differences.

Genetic Variation (VG)

Variance in phenotypic traits due to genetic differences among individuals.

Offspring-Parent Regression

A method of estimating narrow sense heritability by plotting offspring trait values against their parents' average trait values.

Trait Values

The measure of a particular trait in a population, which can vary among individuals.

Midparent value

the offspring's body size against the average size of their parents