The remarkable pervasiveness of attempts to control female sexuality suggests it serves an evolutionary function, possibly the protection of paternity. While a mother can be very confident that her children are her own, men can never be 100 percent positive of their children’s paternity. Controlling his partner’s sexual freedom enhances a father’s confidence (and that of his relatives) in the paternity of the children he is raising. Similar behavior is found in the mate-guarding of prairie voles and other animal species.