Field homology: a meaningless concept.
Most biological homologues involve comparison of single characters in two or more taxa. It is possible, however, to recognize homologous characters between two or more taxa that involve the transformation of one character into many characters or many characters into one character. This type of homology is recognized as field homology and it has been widely used in comparative neuroanatomy. The emergence of the cladistic analysis of embryonic stages in the development of neural characters, however, strongly suggests that field homology is a meaningless concept. When it appears necessary to recognize field homologues, it is because comparisons are being made at an inappropriate level within a given biological hierarchy. Furthermore, recognition of field homologues restricts evolutionary mechanisms to a single mechanism of parcellation as defined by Ebbesson.
Northcutt
R G
RG
Scripps Institution of Oceanography and Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla 92092-0201, USA. rgnorthcutt@ucsd.edu
D000717:Anatomy, Comparative / Q000379:methods*; D000818:Animals; D008954:Models, Biological; D009445:Neuroanatomy / Q000379:methods*; D010802:Phylogeny