Is there any reason to conclude that sperm precedes egg, and not the other way around?

We have the chicken-egg problem, but we don't really have a sperm-egg problem. However, what if there is a sperm-egg problem? This could be seen as similar to the ship of Theseus, in that the egg changes over time because the cells of the ovary continuously replace it even over the course of a single ovulation cycle. <br><br>&#x200B;