Furthermore, in order to have a better understanding of how Sexual Selection affects behaviors in both humans and animals, it is important to know what Sexual Selection is. According to the Oxford Dictionary, Sexual Selection by definition is “Natural selection arising through preference by one sex for certain characteristics in individuals of the other sex”. The existence of it has aged back since the dawn of life, but it was not studied until Charles Darwin proposed his book The Origin of Species in 1859 and developed in another book called The Descent of Man and Selection in Relation to Sex written in 1871 (Trivers, 136) . Charles Darwin began his research on Sexual Selection when he noticed non-survival traits in animals. He observed that
