Quantitative genetics: resemblance among relatives
Now that we know how to partition genetic variance into additive and dominance components (in the unlikely event that we have a quantitative phenotype determined by alternative alleles at a single locus, that we know the genotypic value for each genotype, and that we know the frequencies of the genotypes) we can develop tools to describe how relatives resemble one another. Specifically, we'll be talking about the covariance in traits either between parents and offspring or among siblings. (The covariance between two random variables is very closely related to the correlatiion: Covariance and correlation. In the end, we'll see that we can use the covariance between individuals to estimate additive and environmental components of variance, and in some experimental designs, we can also estimate the dominance component.