Mechanisms of Natural Selection Types of Sexual Selection

We touched upon sexual selection when we learned about natural selection. Essentially when there is a variance in the reproductive success of a particular sex for a given species, secondary sex characteristics will develop in that species, because one sex has the opportunity to choose a mate among the other sex, with females choosing males being most typical. How do these evolve and how are they selected for? What is intrasexual selection vs. intersexual selection? Let's learn about this now!