A survey of dynamical genetics.

The classical view of genetics is based on the central dogma of molecular biology that assigns to DNA a fundamental but static role. According to the dogma, DNA can be duplicated only in identical copies (except for random errors), and no smart mechanism can alter the information content of DNA: in more detail, the direction of transfer of the genetic information is only from DNA through RNA to proteins and never backwards. However, starting from the so-called dynamic genome (McClintock's jumping genes), and the so-called dynamic mutations (such as the trinucleotide expansion or, more generally, the instability of the number of tandem repeats of longer sequences), there is now a growing body of important cases where it is known that the DNA is altered in a more or less sophisticated way, often by smart enzymatic mechanisms. The study of all such dynamic phenomena and of their interpretations can be naturally called dynamical genetics. In this survey we examine a number of such dynamic phenomena, and also some phenomena of great biological importance that have no universally accepted explanation within a static approach to genetics, and for which a dynamical interpretation has been only proposed. Important examples are some controversial but interesting phenomena such as horizontal transmission and Creutzfeldt-Jakob Disease, and those peculiar DNA structures known as G-quadruplexes.