 Their contemporary George C. Williams argued that genetic assimilation proceeds at the cost of a loss of previously adaptive developmental plasticity, and therefore should be seen as resulting in a net loss rather than gain of complexity, making it in his view uninteresting from the perspective of the constructive process of adaptation.However, the preceding phenotypic plasticity need not be adaptive, but simply represent a breakdown of canalization.Several instances of genetic assimilation have been documented contributing to natural selection in the wild.