Ontogeny

Ontogeny is the development of a being from conception (fertilisation) to the final adult form. Ontogenesis therefore includes the embryonic development and later growth of the body, and in the case of human beings, development of their psychology

It is sometimes said in evolutionary biology thatontogenesis is a summary of phylogenesis. This concept introduced by Ernest Haeckel in the XIX^th century is an exaggeration but it highlights the fact that a person's ontogenesis provides considerable information about the phylogenesis of its species, i.e. about its evolutionary history.