Odor-gene covariance in male-female dyads. Relationships between genetic distances (DID) and chemical distances (relative Euclidean, from 170 compounds) in 323 male-female dyads during the nonbreeding (open circles, A and C) and breeding (filled circles, B and D) seasons. The permutation tests on resampling events were performed on the data illustrated in A and B. The permutation tests based on class means were performed on the data illustrated in C and D, which represent mean chemical distances per class of genetic distances, as defined in . The maternal half-siblings (Figures 1 A-B) and the mother-son (Figures 1 C-D) pairs belong to the first category of genetic distances (DID = 0.1 to 0.3), whereas the unrelated pair (Figures 1 E-F) belong to the fourth category of genetic distances (DID = 0.5 to 0.6).