Figure 1.

Mutation as a biological process. a) Mutation as a biological process means that genes interact in the determination of mutation. In the schematic figure, information from three different loci (A, B and C) comes together, through cis-acting elements and trans-acting factors, to affect the probability and nature of a genetic change in one of these loci (B). Inputs into this mutational process are shown by the annotated arrows. The downward arrow represents the writing of mutation, for example by components of the so-called “error-repair” machinery, here not restoring but changing the genetic state from what it was previously. In reality, many more pieces of information than depicted here for simplicity may be involved. b) After meiosis, the changed locus (B*) carries in it an information-signature from the combination that participated in the generation of the change, and thus allows the combination as a whole to have a lasting effect, even though its components are no longer all present.