In Return of the Jedi, Luke tells Leia, "The Force is strong in my family. My father has it. I have it... My sister has it." This implies that Force sensitivity is a hereditary trait.
In The Phantom Menace, upon realizing that young Anakin is strongly force-sensitive, the first question Qui-Gon asks his mother is who the father is, which implies that Force sensitivity is a hereditary trait and the Jedi know it.
In Attack of the Clones, we learn that it is contrary to Jedi philosophy for Jedi to fall in love and marry. This idea is taken even further in Revenge of the Sith, when Padme expresses worry that if the Council finds out Anakin has fathered a child with her, he would be expelled from the Jedi Order.
If Jedi are officially forbidden to marry and have children, and the Order knows that Force-sensitivity is a hereditary trait, this is functionally equivalent to a selective breeding policy to cull Force-sensitivity from the populace, and yet we see plenty of Younglings in the Jedi Temple in the prequel trilogy movies.
If the Jedi are actively not having kids, where do all the little Jedi come from?
