Dear Morphmet community, I'm working with a big GM data set of 92 species and would like to statistically compare levels of static, evolutionary, and ontogenetic allometry to assess levels of constraint in phenotypic development.
For static and evolutionary allometry, I have regressions (shape on size for species) and size-corrected PCAs. I am wondering what is the best way to directly compare those in a statistical framework. I originally compared PC axes between the two data sets using the "Compare Vector Directions" option in MorphoJ, but this seems a bit complicated. Is a simple ANCOVA between the 2 regressions appropriate? They are at least by eye nearly identical. I also have regressions for growth series of 21 of those species, but I'm not sure how those could be directly compared to static or evolutionary allometry. If I do a regression of shape on size for that data set, pooled by species, the R2 is slightly higher, which I expect since it is sampling over the entire postnatal development (from hatchling to adult). However there is a strong trend for some of the species to be significantly down-shifted along the y-axis, although the slopes remain statistically the same (tested using MANCOVA in GeoMorph). Thanks for any advice on how to compare these levels or if it even makes sense to compare ontogenetic allometry to either of the others. Christy ----------------------------- Christy Anna Hipsley University of Melbourne/Melbourne Museum -- 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 [email protected].
