Developmental instability (DI), or the failure of an organism to develop according to its ontogenetic plan, has been receiving a great deal of attention. It may manifest itself in the form of minor physical anomalies (MAPs) or random deviations from anticipated bilateral symmetry (fluctuating asymmetry or FA). DI has been shown to result from genetic and/or environmental factors in man as well as experimental organisms. DI is often used to indicate prenatal insults or increased risk for various disorders. However, appropriate ways to measure DI, especially in the contexts of- genetic epidemiology and teratology, are still being explored. In addition, the basis for genetic vulnerability to DI (homozygosity vs coadaptation) is not understood. A conference/workshop to address these problems is proposed in this application. Researchers with expertise in genetics, statistics and developmental biology will convene to define issues in need of clarification, suggest empirical studies to address these issues and develop recommendations for standardized methods of measuring DI. The proceedings are to be published in a volume by Kluwer Academic Press.