An evolutionary model for the origin of non-randomness, long-range order and fractality in the genome

We present a model for genome evolution, comprising biologically plausible events such as transpositions inside the genome and insertions of exogenous sequences. This model attempts to formulate a minimal proposition accounti ng for key statistical properties of genomes, avoiding, as far as possible, unsupportable hypotheses for the remote evolutionary past. The statistical properties that are observed in genomic sequences and are reproduced by th e proposed model are: (i) deviations from randomness at different length sc ales, measured by suitable algorithms, (ii) a special form of size distribu tion (power law distribution) characterising different levels of genome org anisation in the non-coding, and (iii) extensive resemblance in the alterna tion of coding and non-coding regions at several length scales (self-simila rity) in long genomic sequences of higher eukaryotes, BioEssays 23:647-656, 2001. (C) 2001 John Wiley & Sons, Inc.