Allozymes as diagnostic characters of sibling species of Drosophila

Considerable enzyme variation that is genetically controlled exists within and between natural populations of Drosophila. Our studies of two groups of sibling species show that allozyme differences can be used as species-diagnostic characters. A locus is defined as diagnostic if an individual can be correctly assigned to one of two species with a probability of 99% or higher. Between 15 and 32% of the loci studied are diagnostic for any two of the sibling species. If several diagnostic loci are used, the species of any individual can be diagnosed with virtual certainty.