The paper explores a view on language that is in line with the Strong Minimalist Thesis and that derives an evolutionary scenario predicting language variation in time and space. A stable and uniform UG making available recursive Merge shaped by laws of nature such as simplicity and efficiency has been integrated by a sudden rewiring of the brain into an existing biological system which is comparable to the concept of the faculty of language in the broad sense. The basic oppositions such as symmetry and asymmetry, internal language/thought and externalization, uniformity and diversity, universality and particular languages are derived as an automatic consequence of the architecture of the grammar as it evolved in the human species in concert with general principles of nature. A stable and simple system can be reconciled with a dynamic complex one.