= Recombination change in two-locus haplotype frequencies
{title2=$\Delta x_{AB}=-rD$}
Let the four <haplotype frequencies> sum to one and define $D=x_{AB}x_{ab}-x_{Ab}x_{aB}=x_{AB}-p_Ap_B$. Recombination at rate $r$ removes the excess association: $\Delta x_{AB}=\Delta x_{ab}=-rD$ and $\Delta x_{Ab}=\Delta x_{aB}=rD$. Marginal <allele> frequencies are unchanged. Hence $D<0$ generates more $AB$, whereas $D>0$ removes it; a claim that recombination always increases this combination is false.
Back to article page
