Ontogenesis in a sentence as a noun

The same reason a why during ontogenesis some cells became neurons in the first place while other ones, something else.

Ontogenesis definitions

noun

(biology) the process of an individual organism growing organically; a purely biological unfolding of events involved in an organism changing gradually from a simple to a more complex level; "he proposed an indicator of osseous development in children"

See also: growth growing maturation development ontogeny