Dear morphemetricians, I am comparing cranial morphology in sub-species of baboons. Because the number of variables in my analysis is close to number of individuals, I have chosen to perform a between-groups PCA rather than a CVA and have done so using the ‘groupPCA’ function in the R package “Morpho”. When I explore shape changes along the between-groups PCs, I notice an unexpected amount of asymmetry along the PCs. Specifically, when I compare the shape at positive 3SD from the mean to that at negative 3SD from the mean, the differences seem to be described to some degree by differences in patterns of asymmetry. This seems very odd to me, particularly because, after exploring the data extensively, I am convinced that these asymmetries do not underlie the overall shape variation in the sample—i.e., these differences in the patterns of asymmetry seem to be contributing to differences among groups but not to the overall shape variation in the sample.
Thanks in advance for any insights you may have with regard to this issue. -- MORPHMET may be accessed via its webpage at http://www.morphometrics.org --- You received this message because you are subscribed to the Google Groups "MORPHMET" group. To unsubscribe from this group and stop receiving emails from it, send an email to morphmet+unsubscr...@morphometrics.org.
