Weakening natural selection and decreased randomness are other factors that have slowed the process of human evolution. In the past, Jones explains, only children with genetic mutations that made them fitter lived past the age of 20. But now those genetic mutations don't matter as much because better living conditions, especially in the West, have given way to higher rates of survival and longer life spans, reducing natural selection. As the world becomes increasingly connected, humans are not as likely to lose genes either (in small populations change happens more randomly as genes get lost). In fact, Jones argues, humans are 10,000 more common than they ought to be as a result. Whether people want to believe that is a whole other matter.