Natural selection is the process by which organisms with favorable traits are more likely to reproduce. When natural selection affects humans in a certain population, it can change their characteristics. In the article titled "The Naked Truth," a recent discovery suggests that bare skin was a key factor in the rise of other human traits. Compared to our ancestors, we are less hairy. The reason we started losing hair has to do with the need to control body temperature. Our ancestors probably had to move to a different environment, perhaps in the tropics, where they could find food and water. Therefore, the result of humans adapting to have less hair is due to natural selection, which changed the expression of their genes due to differences.