Human enamel thickness and ENAM polymorphism

Abstract

A gene implicated in human evolution seems to have helped make our tooth enamel thinner. Scientists previously showed, using statistical analyses, that a variant of the tooth enamel development gene ENAM was favored by natural selection. Frank Roberts from the University of Washington, Seattle, USA, and colleagues compared tooth characteristics with ENAM gene differences in African-Americans, in whom the favored variant and the original variant occur in roughly equal proportions. Controlling for age, sex, tooth number and crown length, the researchers found that changes in the ENAM gene affected the thickness of the tooth enamel. Specifically, the variant that conferred an advantage in our species’ evolutionary past produced thinner dental enamel. According to the authors, this is the first direct evidence linking a gene with a known effect on tooth structure to adaptive evolution.

Keywords

enamel / genetics / polymorphisms / tooth / development

References

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