= First-cousin identity-by-descent probabilities
{title2=$(k_0,k_1,k_2)=(3/4,1/4,0)$}
For <first cousins> in an otherwise <outbred pedigree>, compare the copies transmitted from their related parents, who are <full siblings>. These transmissions trace to the same shared grandparent with <probability> $1/2$ and then to the same homologous copy of that grandparent with probability $1/2$, giving $k_1=1/4$. The unrelated parental contributions cannot match, so two shared copies have probability zero. Selecting one random copy from each cousin chooses those two potentially shared copies with probability $1/4$, giving <kinship coefficient> $k_1/4=1/16$.
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