"An attempt to incorporate recent knowledge of epigenetics into the evolutionary theory is presented. As our interest is to clarify evolutionary mechanisms at the molecular level and to connect them to phenotype evolution, the interplay of drift and selection (near-neutrality) on molecular evolution is briefly reviewed. Epigenetic phenomena are partly controlled by genetic systems via chromatin structure, and special attention has been paid to the dynamic evolution of three gene families which encode chromatin components. These gene families are characterized by rapid birth and death of gene copy members, and weak diversity enhancing selection. Also the protein products contain disordered domain that provides flexible chromatin structure. The near-neutrality concept may be extended to their evolution. Here drift, selection and epigenetics become inseparable, and their interplay is thought to have been needed for the evolution of complex gene regulatory systems.
Progress in genomics and epigenetics has prompted me to reconsider some of the basic models of evolution. The current main theory of evolution is Neo-Darwinism, which is based on population genetics. This field has developed in the last century by combining Mendelian genetics with Darwinâs theory of natural selection. Tomoko Ohta, Epigenetics and Evolutionary Mechanisms.
Last date updated on June, 2014