Dear morphometrician, I have recently reviewed 3 genera of catsharks that display a great deal of morphological conservation within the genera, however, there is also prominent sexual dimorphism present (profoundly so in some species). There is quite a bit of shape variation between juveniles and adults, in one genus in particular, but I think that the shape variation is being obscured by the size component. I have a sizeable morphometric data set (# measures >> # taxa & specimens) and have used principal components analysis on the raw data to explore shape variation within each of the genera (not between). The first component was always a general component and accounted for more than 85-90% of the variation in most instances, therefore the bipolar components only contributed relatively little to the overall shape variation resulting in crowded PCA plots. The main reference I have used for the analyses to date has been 'Pimental. 1979. Morphometrics. The multivariate analysis of biological data' however, it doesn't deal with size correction. Can anyone suggest a review that deals with size correction, or can I convert my data to ratios and then log transform the data? I am also looking for reviews of canonical discriminant functions analysis and stepwise discriminant function analysis in an attempt to quantitate differences between species within a genus. Thanks for your help. Brett ************************************ Brett Human Shark Researcher 27 Southern Ave West Beach SA 5024 Australia 61 8 8356 6891 [EMAIL PROTECTED] ************************************
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