“Finally, when humans develop new cultural forms, such as language, tools, lethal weapons, control of fire and cooking of edibles, the long-term effect is the transformation of the human genome itself. In other words, cultural evolution leads to genetic evolution. Examples are cooking, which led to a vast reduction in the size of the human gut, language, which led to radical changes in the human larynx and tongue as well as a considerable increase in brain size, and lethal projectile weapons, which led to changes in the morphology of hand and shoulders, as well as a reorganization of the upper torso musculature. Consider, for instance, that our closest relative, the chimpanzee, spends five hours a day digesting comparing to one for humans, lacks the ability to produce complex vocalizations, and cannot throw a stone with more than minimal accuracy or force.”

— Hubert Gintis, On the Evolution of Human Morality.