Traits that promote survival and reproduction are likely to over time, while traits that do not promote survival and reproduction are likely to decrease over time. This is part of the natural selection process, which is the process that consistently make populations adapted, or better-suited for their environment, over time.Because traits that do not promote survival and reproduction are not essential they will decrease over time.
Since lice feed on human blood, severe and chronic infestation can lead to blood loss and iron-deficiency anemia. 5 In addition, an allergic reaction to louse feces or bites may trigger a rash in some individuals.
