"Of course the theory of cultural evolution (sometimes also described as psycho-social, super-organic, or exosomatic evolution) and the theory of biological evolution are, although analogous in some important ways, hardly identical. Indeed, they often start from quite different assumptions. […] Just to mention several important differences: although biological theory now excludes the inheritance of acquired characteristics, all cultural development rests on such inheritance - characteristics in the form of rules guiding the mutual relations among individuals which are not innate but learnt. To refer to terms now used in biological discussion, cultural evolution simulates . Moreover, cultural evolution is brought about through transmission of habits and information not merely from the individual's physical parents, but from an indefinite number of 'ancestors'. The processes furthering the transmission and spreading of cultural properties by learning also, as already noted, make cultural evolution incomparably faster than biological evolution. Finally, cultural evolution operates largely through group selection; whether group selection also operates in biological evolution remains an open question - one on which my argument does not depend. Despite such differences, all evolution, cultural as well as biological, is a process of continuous adaptation to unforeseeable events, to contingent circumstances which could not have been forecast. This is another reason why evolutionary theory can never put us in the position of rationally predicting and controlling future evolution. All it can do is to show how complex structures carry within themselves a means of correction that leads to further evolutionary developments which are, however, in accordance with their very nature, themselves unavoidably unpredictable."