Figure 1. Punnett square. A simple graphical method developed by Reginald Punnett in the early twentieth century to calculate all of the potential combinations of offspring genotypes that can occur and their probability given the parent genotypes. The statistical results of Punnett squares are based on the assumption of an infinite number of successful matings and the absence of evolutionary mechanisms.

Figure 2. Consanguineous mating patterns and the coefficients of inbreeding (F) for the resulting children. Triangles represent males, circles are females, equal signs indicate sexual unions, vertical lines show descent bonds and horizontal lines show codescent bonds.

Figure 3. Exogamy and endogamy operate simultaneously in limiting mate selection.

Figure 4. Relationship between unilineages, clans, phratries and moieties.