Is the fast/slow allozyme variation at the Adh locus of Drosophila melanogaster an ancient balanced polymorphism?

摘要

Any general model of population genetics must be able to accommodate observations both of standing variation (polymorphism) and of evolutionary history (divergence). Interpretation of the connection (or lack thereof) between these two kinds of data impinges directly on our ideas of evolutionary mechanism. Studies of the alcohol dehydrogenase locus (Adh) in Drosophila melanogaster and its close relatives provide what is perhaps our most detailed description of variation and evolution of a gene at the molecular and phenotypic levels.