Mitochondrial (dark gray) versus consensus nuclear geographic clines (light gray) along with support envelopes. Genetic disequilibria (D) estimates (multiplied by four for visualization purposes) are superimposed on the clines. The short-dashed line represents cytonuclear disequilibrium (MLE pairwise D over 3 possible pairs of nuclear/mt loci), the long-dashed line represents between nuclear loci disequilibrium (MLE pairwise D over 3 possible pairs of the nuclear markers), and the solid line represents within locus disequilibrium (MLE of heterozygote deficit over the three nuclear loci).
Devitt et al. BMC Evolutionary Biology 2011 11:245 doi:10.1186/1471-2148-11-245