An evolutionary crisis occurred when the arms of our ancestors became long enough to make masturbation possible.

During this transition, humans who had longer arms had an evolutionary advantage, as they could reach bananas that others with shorter arms could not reach. As millennia passed, arms became longer. An evolutionary crisis occurred when our ancestors became able to reach their genitals with their hands. Prior to this evolutionary moment, an individual could only achieve orgasm by copulating and thus producing offspring. But now an individual could achieve orgasm without copulating and producing offspring.