The decisions we make today are molded by the decisions of our successful ancestors and the traits that they passed on to us.
But I can understand why you find such an idea disturbing. The knowledge that your little cunty habits and mannerisms won't be passed on to a new generation of women, that as far as the species of mankind is concerned you will prove to be nothing more than an anomalous and irrelevant blip no more important to your species than an aborted goat, might keep you awake at night.