Homologies, analogies, synapomorphies and homoplasies: problems and considerations

The author discusses, on the evidence of some typical examples, some problems in the assessment of homologies which have surfaced by the integration of ultrastructural and genetic evidences in the assessment of the morphologic and evolutionary significance of structures. He thence considers problems of correct assessment of homologies as true apomorphic rather than homoplastic traits and which are often overlooked in the construction of cladistic matrixes. His conclusions are that a more comprehensive approach in morphological research should be stressed and that a strong effort is badly needed for the development of classical comparative anatomy versus the present trend towards ultra specialized studies; moreover, at the present stage of research, the available evidence is generally quite insufficient for the development of reliable matrixes of data, so that a more empirical and pragmatic approach is much safer.