© 1998 by The Society for Integrative and Comparative Biology
Morphological Approaches to Phylogeny1
Zoological Museum (University of Copenhagen) Universitetsparken 15, DK-2100 Copenhagen, Denmark
Correspondence: 2E-mail: cnielsen{at}zmuc.ku.dk
SYNOPSIS. Traditional views on the interrelationships of the major animal groups are based on morphological characters, but molecular data of various types have in the last decade given indications of new and sometimes quite puzzling phylogenies. This should be an incentive not only to reevaluation of the available morphological characters but also to new studies to fill the voids in our knowledge. Modern morphology is not concerned only with traditional studies of structure and ontogeny of organ systems, but also with newer methods, such as SEM, TEM, immunocytochemistry, and cell marking. This has given morphology new dimensions, but it also has shown that vast areas of the animal kingdom remain very poorly known even through traditional studies. Phylogenetic trees built on morphology (and molecular trees with morphological characters added) demonstrate morphological characters that are in conflict with the phylogeny, and therefore should be reinvestigated; they also indicate areas where new research can contribute significantly to our understanding of the pathways of the evolution. Morphological phylogeny has the distinct advantage that characters of ancestors can be inferred and the evolutionary changes checked in terms of functional continuity and hypotheses of adaptation.