Ma'anar ƙamus na kalmar "ontogeny" shine tsarin ci gaban kwayoyin halitta, tun daga farkon matakinsa a matsayin kwai mai hadi zuwa cikakke kuma balagagge siffa. Yana nufin canje-canje iri-iri da matakan ci gaban da kwayoyin halitta ke fuskanta yayin girma da girma. An bambanta Ontogeny sau da yawa da "phylogeny," wanda ke nufin tarihin juyin halitta da ci gaban wani nau'i na tsawon lokaci.