Variability Mutational

Mutational variability is genotypic variability caused by the occurrence of mutations.

Mutations are random changes in the structure of DNA that lead to the appearance of new alleles of genes. They can arise under the influence of various mutagenic factors (ultraviolet radiation, chemicals, radiation, etc.) or spontaneously during cell division.

Mutational variability is the only source of new genetic information. It ensures the emergence of new characteristics and properties in organisms. Most mutations are lethal or neutral. However, some of them can give an advantage to individuals and have a positive effect. Such mutations are fixed in the population through the process of natural selection and lead to the evolutionary progress of the species.

Thus, the mutation process underlies microevolution and is the driving force of biological evolution as a whole. Variation due to mutation provides the raw material for the action of natural selection.

Mutational variability Variability that arises as a result of the appearance of new characteristics inherent in the ancestors or descendants of an organism - its ability to change under the influence of unfavorable external conditions (mutational variability). Mutational variability is based on changes in the structure of chromosomes - mutations, i.e. a sudden, abrupt change in their genetic composition and structure. Mutational variability was first studied by G. Mendel when studying the inheritance of monohybrid traits in peas (a certain number of ischial branches, color traits, etc.). Subsequently, mutational variability was studied by T. Morgan while working with Drosophila. Researchers have paid much attention to the behavior of genes over generations. The genes that determine the development of branches of a certain color did not appear in the first generation, but they are consistently transmitted