bean-bag genetics

bean-bag genetics
 n.— «As Robert Brandon famously stated, genes are invisible to selection. Yet, population genetics assumes that the genes are visible to selection. How? Via phenotypes. But that is an oversimplified notion that a mutation in one gene predictably leads always to the same change in the phenotype. This one-gene one-trait view is sometimes called “bean-bag genetics.”» —“Books: “Biased Embryos and Evolution” by Wallace Arthur” by Coturnix Blog Around the Clock July 8, 2007. (source: Double-Tongued Dictionary)