Nabokov argued that a slight resemblance between one insect and another or between an insect and its environment could not be furthered by the function or purpose it served, leading gradually to mimicry. The subtleties of Nabokov's argument against Darwinian gradualism have been missed by most of his readers. He did not critique Darwinism in the same way that Creationists do. Nabokov did believe that natural selection could explain many adaptations and shifts in the direction of evolution, but he did not think it could explain mimicry. He realized there were other forces at work assisting natural selection, which were especially apparent in the case of "mimicry." Recent work in what is called "structural" and "neutral" evolutionary theory supports Nabokov's views, which seem to have been influenced by teleomechanism, a form of theoretical biology derived from Kantian teleology.