 Before we consider the analysis of variance and its contribution to heritability measures, it is helpful to understand the general concept of heritability. Heritability is a measure of genetic influence on variation. If a trait has high heritability, its varying from individual to individual in a population can be explained genetically. An imaginary example illustrates one way of assessing heritability. Say we have two students from a class and student a is 6′2″ and student b is 4′2″. To discover the influence of genes on height, we could clone both students and then swap the clones’ environments and see what happens. In the figure below, the environments that a and b grew up in are \(\rE a\) and \(\rE b\). Clones of a and b are \(\rC a\) and \(\rC b\).