Homology and causes
Article first published online: 6 FEB 2005
Copyright © 1982 Wiley-Liss, Inc.
Journal of Morphology
Volume 173, Issue 3, pages 305–312, September 1982
How to Cite
Van Valen, L. M. (1982), Homology and causes. J. Morphol., 173: 305–312. doi: 10.1002/jmor.1051730307
- Issue published online: 6 FEB 2005
- Article first published online: 6 FEB 2005
Homology is resemblance caused by a continuity of information. In biology it is a unified developmental phenomenon. Homologies among and within individuals intergrade in several ways, so historical homology cannot be separated sharply from repetitive homology. Nevertheless, the consequences of historical and repetitive homologies can be mutually contradictory. A detailed discussion of the rise and fall of the “premolar-analogy” theory of homologies of mammalian molar-tooth cusps exemplifies such a contradiction. All other hypotheses of historical homology which are based on repetitive homology, such as the foliar theory of the flower considered phyletically, are suspect.