ABSTRACT
Evolutionary progress has often been discussed in terms of the acquisition of new genetic information. The quantity of genetic information contained in a genome can be assessed in the number of nucleotide pairs, that is, total mass of DNA. Within the metazoa, however, DNA per cell varies from species to species in a manner which shows little relation to the phylo-genetic position of these species. The largest quantities of DNA per genome are found not in the most highly advanced organisms, but, for instance, among vertebrates, in some of the amphibia. It states that any tendency to increase the quantity of information in the genome during evolution will be held in check because the rate of advance under natural selection will be inversely proportional to the number of informational units.
