title: Homology and ontogeny: pattern and process in comparative developmental biology.
abstract: In this article the interface between development and homology is discussed. Development is here interpreted as a sequence of evolutionarily independent stages. Any approach stressing the importance of specific developmental stages is rejected. A homology definition is favoured which includes similarity, and complexity serves as a test for homology. Complexity is seen as the possibility of subdividing a character into evolutionarily independent corresponding substructures. Topology as a test for homology is critically discussed because corresponding positions are not necessarily indicative of homology. Complexity can be used twofold for homology assessments of development: either stages or processes of development are homologized. These two approaches must not be con-flated. This distinction leads to the conclusion that there is no ontogenetic homology "criterion".
authors.affiliation: Humboldt-Universität zu Berlin, Institut für Biologie/Vergleichende Zoologie, Philippstr. 13, DE-10115 Berlin, Germany. gerhard.scholtz@rz.hu-berlin.de
authors.forename: Gerhard
authors.initials: G
authors.lastname: Scholtz
mesh_terms: D000818:Animals; D005075:Biological Evolution; D015509:Developmental Biology / Q000379:methods*; D018507:Gene Expression Regulation, Developmental; D016678:Genome / Q000235:genetics; D006801:Humans; D009024:Morphogenesis; D009626:Terminology as Topic