Genetic diversity increases a species' chances of survival
Humanity has long ceased to be animals; it no longer needs to adapt to anything.
You are neglecting the emotional and psychological aspect of the issue.
Pfft, what do emotions and psychology have to do with it? A healthy person can perfectly control this.
И пока в кармане пачка милкиуэйев - значит все не так уж плохо на сегодняшний день