On Applications of Geometric Morphometrics to Studies of Ontogeny and Phylogeny

The ® eld of ge om etric m orphom etrics is relatively new (see Books tein , 1991; R ohlf and M arcus, 1993) and has show n very rap id pro gress over the last few years.A s m igh t be exp ected du rin g a period of rapid develop m en t, there can be technical problem s in som e of the p ioneerin g studies as biologists attem p t to apply the new tools.It is only now becom ing clear how the new techniques shou ld be com bined in order to carry out com prehens ive analyses of real data sets.Bookstein (1996b) gave a list of recom m en dations for such ap plications, and Bo okstein (1996a) gave severa l com prehen sive exam ples of m orphom etric analyses.However, these accounts do no t address som e of the typ es of ap plications that are of p articular in tere st in sy stem atic b io lo g y.B o o k st ein (1 9 9 4 ) p o in t e d ou t problem s w ith usin g ge om etric m orphom etric methods in the usual characterbased cladistic studies.He em phasized that m orphom etrics cann ot sup ply hom ologou s sh ap e characters.The purp ose of this note is to com m ent about som e recent ap plications of m orphom etric m ethods in sy stem atic biolog y.This note is p articularly concerned w ith the morphom etric methods used by Zelditch et al. (1992Zelditch et al. ( , 1993Zelditch et al. ( , 1995)), Sw idersk i (1993), Fink and Zeld itch (1995), and Zelditch and Fink (1995).The se m ethods were also used by Burke et al. (1996).For conven ience, these studies w ill be referred to usin g the acrony m Z& F. In these studies the authors investigated the use of partial warp s (Bookstein, 1991) as variables in ontogenetic and taxonom ic studies.They were im pressed by their observation that differen ces in p artia l warp s scores (R ohlf, 1993b) corre sponded to sh ape differen ces