ABSTRACT
One general characteristic of the mechanism of somatic change is that it represents a multi-stage process. It incorporates a wide array of tools responsible for changing the genetic program that forms an organism as well as for regulating the pace and depth of these changes. This change is carried out primarily by means of horizontal mechanisms, that is, via interactive behavior of changing cells. The role of telomeres was first uncovered by Hermann Müller. He showed that a Drosophila chromosome without an end is unable to recover. Barbara McClintock, in her work with unstable corn chromosomes, hypothesized the existence of normal structures that ensure chromosome unity. During the embryonic stage of fetus development, the main concern is with the formation of an organism according to the inherited genetic code and the environment, including the womb, in which the fetus is developing. During childhood, prior to puberty, the focus is on growth, basically within the framework of the inherited genetic information.
