purpose of this contribution, is the discussion on what actually causes evolution(" Why do polar bears have white fur and other bears brown fur? ) This discussion on what is called adaptationism is about the importance of natural selection in the process of evolution. What is the actual power of natural selection? The question is important for the evolution of law because it may give us some insight into the question why it is that some legal rules survive and others do not. Biology teaches us that as to the direction of the evolution, adaptation is the main principle Organisms fit themselves into niches of viability offered by their environments. They have to in order to survive the pressure of selective competition from other organisms. What may be of interest for the study of law is that the direction of adaptation is usually toward simplicity, in particular when homogenisation of the environment reduces the number of distinct niches available. The movement is toward complexity when there are only a few species that proliferate within a new environment with many unfilled niches. I will come back to this point later Theoretical biologist Sober provides us with a good insight into another discussion. To predict what the mechanism of evolution leads to, it is possible to make use of simple models of the selection process(for example in case of the evolution of running speed in zebras, fast zebras may survive over slow zebras), taking into account only natural selection and not mutation or other evolutionary processes and abstaining from the fact that running speed may not evolve independently of other characteristics the zebra has. Adaptationists would say that any refinement of the simple model does not affect the prediction of how the running speed would evolve. If this were also true for the law, it would mean that selection of legal rules is a straightforward process, not hampered by other factors than the pursuit of finding the best rule available. As we shall see, however this is not the case in the real world As Darwin intended a theory on how life evolves, other scholars have expanded his theory to other disciplines. Among these are history, psychology, political science, history of science,sociology,3 ethics, 0 linguistics# and economics. In this section, I will focus on Also in this application of evolutionary theory, the idea of an ld a 33 Jack Hirshleifer, Evolutionary Models in Economics and Law, in EVOLUTIONARY ECONOMICS 205(Ulrich Witt ed, 1993) 34 SOBER, supra note 28, at 119 55 THE RETURN OF SCIENCE: EVOLUTIONARY IDEAS AND HISTORY(David Gary Shaw Philip Pomper,eds 1999) HENRY PLOTKIN, EVOLUTION IN MIND: AN INTRODUCTION TO EVOLUTIONARY PSYCHOLOGY(1997) F.A. HAYEK, LAW, LEGISLATION AND LIBERTY (1973-1979) KARL R. POPPER, OBJECTIVE KNOWLEDGE: AN EVOLUTIONARY APPROACH (1979) 39 On the influence of Herbert Spencer cf. GEOFFREY M. HODGSON, ECONOMICS AND EVOLUTION 81(1993) On socio-biology and the claims it makes about explaining morality, cf. SOBER, supra note 28, at 202; see notably the groundwork laid by E.O. WILSON, SOCIOBIOLOGY: THE NEW SYNTHESIS(1975)and R ALEXANDER, THE BIOLOGY OF MORAL SYSTEMS (1987) For an overview cf. JOHN MAYNARD SMITH EORS SZATHMARY, THE ORIGINS OF LIFE: FROM THE BIRTH OF LIFE TO THE ORIGIN OF LANGUAGE(1999); J. MAYNARD SMITH, EVOLUTION AND THE THEORY OF GAMES (1982); JOHN H. BECKSTROM, DARWINISM APPLIED: EVOLUTIONARY PATHS TO SOCIAL GOALS(1993) INSTITUTIONS: ON EVOLUTIONARY ECONOMICS AND THE EVOLUTION OF ECONOMICS(1999): Witt(ed ) supra note 33; HODGSON, supra note 39. On the relationship with biology cf. John Foster, Biology and Economics. in THE ELGAR COMPANION TO INSTITUTIONAL AND EVOLUTIONARY ECONOMICS A-K 23 55 purpose of this contribution, is the discussion on what actually causes evolution (“Why do polar bears have white fur and other bears brown fur?”). This discussion on what is called adaptationism is about the importance of natural selection in the process of evolution. What is the actual power of natural selection?32 The question is important for the evolution of law because it may give us some insight into the question why it is that some legal rules survive and others do not. Biology teaches us that as to the direction of the evolution, adaptation is the main principle. Organisms fit themselves into niches of viability offered by their environments. They have to in order to survive the pressure of selective competition from other organisms. What may be of interest for the study of law is that the direction of adaptation is usually toward simplicity, in particular when homogenisation of the environment reduces the number of distinct niches available. The movement is toward complexity when there are only a few species that proliferate within a new environment with many unfilled niches.33 I will come back to this point later. Theoretical biologist Sober provides us with a good insight into another discussion.34 To predict what the mechanism of evolution leads to, it is possible to make use of simple models of the selection process (for example in case of the evolution of running speed in zebras, fast zebras may survive over slow zebras), taking into account only natural selection and not mutation or other evolutionary processes and abstaining from the fact that running speed may not evolve independently of other characteristics the zebra has. Adaptationists would say that any refinement of the simple model does not affect the prediction of how the running speed would evolve. If this were also true for the law, it would mean that selection of legal rules is a straightforward process, not hampered by other factors than the pursuit of finding the best rule available. As we shall see, however, this is not the case in the real world. As Darwin intended a theory on how life evolves, other scholars have expanded his theory to other disciplines. Among these are history,35 psychology,36 political science,37 history of science,38 sociology,39 ethics,40 linguistics41 and economics. In this section, I will focus on evolutionary economics.42 Also in this application of evolutionary theory, the idea of an 32 Id at 119. 33 Jack Hirshleifer, Evolutionary Models in Economics and Law, in EVOLUTIONARY ECONOMICS 205 (Ulrich Witt ed., 1993). 34 SOBER, supra note 28, at 119. 35 THE RETURN OF SCIENCE: EVOLUTIONARY IDEAS AND HISTORY (David Gary Shaw & Philip Pomper, eds., 1999). 36 HENRY PLOTKIN, EVOLUTION IN MIND: AN INTRODUCTION TO EVOLUTIONARY PSYCHOLOGY (1997). 37 F.A. HAYEK, LAW, LEGISLATION AND LIBERTY (1973-1979). 38 KARL R. POPPER, OBJECTIVE KNOWLEDGE: AN EVOLUTIONARY APPROACH (1979). 39 On the influence of Herbert Spencer cf. GEOFFREY M. HODGSON, ECONOMICS AND EVOLUTION 81 (1993). 40 On socio-biology and the claims it makes about explaining morality, cf. SOBER, supra note 28, at 202; see notably the groundwork laid by E.O. WILSON, SOCIOBIOLOGY: THE NEW SYNTHESIS (1975) and R. ALEXANDER, THE BIOLOGY OF MORAL SYSTEMS (1987). 41 For an overview cf. JOHN MAYNARD SMITH & EORS SZATHMARY, THE ORIGINS OF LIFE: FROM THE BIRTH OF LIFE TO THE ORIGIN OF LANGUAGE (1999); J. MAYNARD SMITH, EVOLUTION AND THE THEORY OF GAMES (1982); JOHN H. BECKSTROM, DARWINISM APPLIED: EVOLUTIONARY PATHS TO SOCIAL GOALS (1993). 42 The extensive literature on evolutionary economics includes GEOFFREY M. HODGSON, EVOLUTION AND INSTITUTIONS: ON EVOLUTIONARY ECONOMICS AND THE EVOLUTION OF ECONOMICS (1999); Witt (ed.), supra note 33; HODGSON, supra note 39. On the relationship with biology cf. John Foster, Biology and Economics, in THE ELGAR COMPANION TO INSTITUTIONAL AND EVOLUTIONARY ECONOMICS A-K 23