Distance, correlation and mutual information among portraits of organisms based on complete genomes

Based on the portrait method proposed by Hao et al. (Chaos Solitons Fractal s 11 (6) (2000) 825), four parameters (distance, correlation coefficient, e ntropy and mutual information) are introduced to provide exact measures of the difference between a real genome and the "white noise" genome of it. He re the "white noise" genome of a real genome means a random sequence based on the frequencies of four kinds of nucleotides, appearing in the real geno me. These parameters can also be used to discuss the classification and evo lution among organisms. The evolution trees of some bacteria based on these parameters are given. (C) 2001 Elsevier Science B.V. All rights reserved.