Estimated degree of relationship between pairs of individuals versus known degree of relationship. Pedigree information was used to identify 2802 pairs of genotyped individuals that share exactly two common ancestors (a mated pair) and classify them according to the degree of their relationship (horizontal axis). The number of pairs in each category is indicated by the histogram below. Within each category, the areas of the filled circles indicate the proportion of those pairs with various estimated degrees of relationship between a pair (vertical axis; two ancestors, two degrees of freedom, α = 0.001). The total area within a category is a constant across categories. Pairs with a known but undetected relationship are represented across the top. Pairs with no known relationship are represented on the right.
