This first lecture introduces the basic concepts of evolutionary thinking and examines their explanatory power in relation to law. There is no single, dominant theory of evolution that is relevant to law, but rather a family of interrelated ideas and models. In principle, genetic models may be of interest to law as analogies or metaphors, rather than as descriptions of legal or other social phenomena. We need to be very careful to scrutinize claims about the direct influence of genetic factors on social institutions, along the lines of the disciplines of "sociobiology" or "evolutionary psychology". While it is clear that there is a genetic basis or "substrate" for all human behavior, we have no reliable way of knowing to what extent genetic factors influence the institutional structures observed in modern society, nor any valid theoretical or empirical basis for believing that human genetic variation is reflected in the intercultural and transnational diversity we observe today. A more modest and defensible, and therefore more useful, hypothesis is that human institutions have evolutionary properties resembling the mechanisms identified in the biological sciences. However, we should not imagine that the mechanisms of social evolution are identical to those of the underlying processes operating in nature.
With these caveats, a version of the Darwinian algorithm of "variation, selection and retention" can explain how legal rules evolve in response to changes in their economic, political and technological environments. This model fits well with the "path-dependence" of law, and also accounts for the cognitive function of the legal system, i.e. the sense in which the rules and concepts used in legal reasoning enable useful social knowledge to be retained and applied. The model is far removed from the notion of the evolution of law according to "evolution towards efficiency", as suggested by the modern literature on the economic analysis of law: legal change is rather error-prone and chaotic, with no guarantee of an optimal outcome. That said, law of the kind that has evolved alongside the contemporary rise of the market economy and the rule of law has properties that largely favor the maintenance of the democratic-liberal order. The role of law is not limited to stabilizing economic expectations, important though this is. The legal order is also one of the ultimate guarantors of effective participation by citizens and groups in the social and economic life of the political system.
