Extended Data Fig. 1: Principal component analysis (PCA) of pelvis shape, jointly for humans and chimpanzees. | Nature Ecology & Evolution

Extended Data Fig. 1: Principal component analysis (PCA) of pelvis shape, jointly for humans and chimpanzees.

From: Sex differences in the pelvis did not evolve de novo in modern humans

Extended Data Fig. 1

The black arrows represent the allometry vectors, which were estimated here using a non-pelvic size measure for each species (femoral head diameter in chimpanzees and body height in humans, compare Extended Data Fig. 2) in contrast to Fig. 2, where they were estimated based on pelvic centroid size. For these non-pelvic size variables, z-scores were computed independently for each species. The allometry vectors were then estimated by regressing the shape coordinates on the z-scores for each species and projected into the PC spaces. As in Fig. 2, the allometry vectors are species-specific but not sex-specific. The vectors are shown twice, superimposed on the sex means for each species. The direction of allometry is distinct from the direction of sex differences in both species. The individual data shown are the same as in Fig. 2. Each small point corresponds to an individual (humans: males=blue, females=red; chimpanzees: males=light blue, females=light red). The larger points in the same colors correspond to the sex means for each species.

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