Processes of Change in Genetic Systems

The most basic change processes are those that result in individual variations that are genetically transmitted, a condition first recognized by Darwin as essential to evolutionary change, although he, in common with other biologists of his time, had no knowledge of the what the processes might be. One of these is the process of meiosis in sexual reproduction, which is a powerful and constant producer of variation in genotypic systems. It in turn is dependent upon another change process, that of gene mutation, which has a double role, that of producing variation among the genes, the entities composing genotypic systems, and less importantly, of producing changes in populations of genes.