This paper contends that law is in essence an evolutionary phenomenon that can, and indeed should, be studied in the light of biological mechanisms. Law can be seen as an extended phenotype of underlying genes. In addition, legal systems can be seen as congruous to genetic mechanisms. Properties of genes have an impact on legal systems in a fractal-like manner. Hence, it is not surprising that notions of stability, replication, and reciprocity that are important in biological systems will also be important in legal systems. As a result legal systems can be constructed in a way that is congruent with the genetic advantage of group members. Law, exposure, and punishment can diminish deviant behaviour and restore balance. Law may not be particularly subject to natural selection, but it will certainly be built on the foundations of natural selection.