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Genotype, phenotype, and developmental biology of molar tooth characters
Author(s) -
Jernvall Jukka,
Jung HanSung
Publication year - 2000
Publication title -
american journal of physical anthropology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.146
H-Index - 119
eISSN - 1096-8644
pISSN - 0002-9483
DOI - 10.1002/1096-8644(2000)43:31+<171::aid-ajpa6>3.0.co;2-3
Subject(s) - cusp (singularity) , biology , evolutionary biology , molar , phenotype , developmental genetics , dentition , genetics , gene , paleontology , geometry , mathematics , regulation of gene expression
Primate molar shapes reflect developmental and ecological processes. Development may constrain as well as facilitate evolution of new tooth shapes, affecting how reliable dental characters are in phylogenetic studies. Much of the genetic machinery of development uses the same genes among different organs, including teeth, limbs, and feathers. Furthermore, within a tooth, the development of individual cusps repeatedly uses the same set of developmental genes, forming a “developmental module.” The repeated activation of the developmental module can explain the cumulative variation in later‐developing cusps. Therefore short, later‐developing cusps may be evolvable but also more homoplastic. This patterning cascade mode of cusp development can be used to explain the variational properties of dental characters and character states related to cusp initiation. The developmental basis and variational properties of crown termination, cusp shape, and cusp configuration characters are currently less well understood. It is unlikely that there is a simple “gene to phenotype” map for dental characters. Rather, the whole cusp pattern is a product of a dynamic developmental program manifested in the activation of the developmental modules. Yrbk Phys Anthropol 43:171–190, 2000. © 2000 Wiley‐Liss, Inc.