Allow me to start by observing that, in the word “reproduction”, the initial syllable, Re, has a remarkable importance, at least to the geneticist. In fact, when we say “reproduction”, we do not merely mean that a living being is produced, but we also mean that the production of such a living being implies the repetition of a model that is present in the species, in the population, in the family.

Moreover, the model that is reproduced is not only that of an embryo, of a fetus, of a neonate, but is also that of a child, of an adolescent, of an adult, of an old man.

Reproduction is therefore the repetition of a model that is not limited to the amphimixis, to gestation or birth, but that dominates throughout the entire cycle of life with a continuous variability, that is, through a dynamic and individualized phenogenesis. Such an extension of the concept of reproduction from the stage of conception to the standards of the successive ages, requires that a view based on immediate times be substituted with a view based on long times. This means, in other words, that a new parameter should be explicitly considered as part of the zygote's blueprint: the chronologic parameter.