Scaling laws in the functional content of genomes: Fundamental constants of evolution?

TL;DR

This paper investigates power-law scaling laws in genome composition, suggesting these patterns are fundamental constants of evolution and have implications for understanding cellular regulatory design.

Contribution

It revisits and extends previous findings on genome scaling laws with new data and proposes that these laws reflect fundamental constants of evolutionary processes.

Findings

Genes in functional categories scale as power laws with genome size

Proposes that scaling exponents are fundamental constants of evolution

Suggests quadratic scaling of regulatory genes with genome size

Abstract

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.