In my continuing effort to develop R Shiny applications that illustrate principles of population genetics, I’ve just added one that illustrates the resemblance between parents and offspring. It’s based on a really simple model (one locus, two alleles, and the same environmental variance for all genotypes). You can see phenotype distributions, components of genetic variance (calculated from the underlying genotypic values and allele frequency) and simulate a parent-offspring regression with different sample sizes.