TESTING ELECTROPHORETIC DATA FOR AGREEMENT WITH HARDY-WEINBERG EXPECTATIONS

Electrophoretic data from marine organisms are routinely tested for conformity to expectations of the Hardy-Weinberg rule, but the statistical procedures used and the interpretation of their results are often flawed. This paper summarizes literature on statistical testing for Hardy-Weinberg equilibrium and suggests an analytical strategy based on carrying out computationally simple goodness-of-fit chi-2 tests (with pooling and correction factors for continuity if necessary) when appropriate, and resorting to computationally tedious, exact tests when necessary. It recommends adjustments of significance levels to avoid the large Type-I error that may result from multiple tests for Hardy-Weinberg equilibrium, one for each locus and each population. It points out the obvious but common error of interpreting non-significant tests as evidence of conformity to Hardy-Weinberg expectations, and makes suggestions as to how tests that produce significance can be used to reach conclusions of biological relevance.