Pablo Yes, allometry will persist in most data sets (i.e., if there is a sufficient range of variation in size).
Geometric morphometrics (landmark-based and outline-based alike) uses a strictly geometric definition of shape. These methods apply a scaling to remove variation of size (e.g., scaling to unit centroid size), but this will not remove the allometric effects of size on shape. This geometric scaling is the same as what's used in photography: pictures of babies and grown-ups are scaled until they fit the 9-by-13 cm picture format. But of course you will still be able to tell that the baby is smaller that the grown-up because we know the association between the shape of a person and their size. If you want to do an analysis, for example, distinguishing between two groups with a substantial amount of size variation, you may still need to apply some form of "size correction" to your shape data to remove the allometric effects on shape variation. Normally, you will do the size correction by using the residuals from a multivariate regression of shape on size. Depending on how different the allometries within your groups are, this might be a bit tricky. The solution will depend on your specific problem. I hope this helps. Best wishes, Chris -- ****************************************************************** Christian Peter Klingenberg School of Biological Sciences University of Manchester 3.614 Stopford Building Oxford Road Manchester M13 9PT United Kingdom Telephone: +44 161 275 3899 Fax: +44 161 275 3938 E-mail: [EMAIL PROTECTED] Web: http://www.sbs.man.ac.uk/chrisk Office: 3.530 Stopford Building (this is not the mailing address!) ****************************************************************** == Replies will be sent to list. For more information see http://life.bio.sunysb.edu/morph/morphmet.html.
