The population dynamics of gene substitution in molecular evolution

Abstract

The population dynamics of gene substitution at the molecular level is reviewed and discussed with particular reference to the stochastic approach in evolutionary studies. After a brief historical development of the theories on the mechanism of evolution, the diffusion process method is used to discuss the rate of gene substitution and the average time taken to achieve it. Some aspects of neutral theory of molecular evolution are reviewed. The rate of evolution at the molecular level is discussed with reference to haemoglobin in vertebrates. The level of heterozygosity in natural populations under infinite sites model is estimated by the conditional approach and compared with that obtained by the unconditional approach. Most of the treatment is based on the results obtained in relation to the neutral theory of molecular evolution and on stochastic problems and methods in population genetics.