Scaling laws in the functional content of genomes: Fundamental constants   of evolution?
  With the number of fully-sequenced genomes now well over a hundred it has become possible to start investigating if there are any quantitative regularities in the genetic make-up of genomes. In (physics/0307001), I originally showed that the numbers of genes in different functional categories scale as power laws in the total number of genes in the genome. In this chapter I revisit these results with more recent data and go into considerable more depth regarding the implications of these scaling laws for our understanding of the regulatory design of cells. In addition, I further develop the evolutionary model first proposed in (physics/0307001), which suggests that the exponents of the observed scaling laws correspond to fundamental constants of the evolutionary process. In particular, I put forward an hypothesis for the approximately quadratic scaling of regulatory and signal transducing genes with genome size. 
Erik van Nimwegen