Genetics is in a postgenomic era, and this article illustrates this epistemological evolution using the debate between developmental criticism and traditional biometric genetics about gene × environment interaction. Quantitative geneticists are blamed for failing to respect the complexity of development; as a response, they claim a defensive position, called isolationist pluralism, which supports the idea that studying development is not their problem. But postgenomics seems to have accepted and integrated some developmental criticisms and the isolationist perspective has been challenged during (...) the last few years. The developmental and quantitative traditions actually represent two different levels of analysis, but biometrics has also a clear developmental explanatory potential as it suggests statistically the existence of mechanical causes. Both traditions work together to go ever further in the knowledge of the phenomena being studied. Postgenomic pluralism, instead of being isolationist, may be considered pragmatic. (shrink)