First Woman and Man: "Mother-Right"
The concept of a family with a father, mother, and child (or patriarchy), is unfortunately not a true picture of the original family. The first type of family was matriarchal since the role of the father in procreation was unknown. Even today, among tribes in Central Australia and the Trobriand Islands, we find people possessing no knowledge of the nature of paternity. In such a society, even if the father lives with the mother, he is not considered the head of the family.
Available evidence concludes that the earliest human groups or families consisted not of father, mother, and their descendants, but of mother and her descendants in the female line, since no other line of descent was recognized at that time. The system of female descent was known as "Mother-Right."
The role of gender in the evolution of man is very important. Most of all of the existing evidence opposes the theory of male superiority. In nearly all animal species, the female is the superior and dominant type. Even in the human race, before the rise of civilization, female rule was practically universal. Prior to the vertebrate level, the male sex is relatively unimportant.
In primitive society humans lived in groups or clans each of which was based on common descent in the female line, and the members were joined together for mutual protection, and marriage within the group was forbidden. Members of one group would have to pick a mate from another group. This type of matrimony is known as exogamy, this promiscuity was an evolution that led successively to group-marriage, loose monogamy, and finally the patriarchal family of today.
In primitive society, exogamy is closely connected with another system called totemism. Totems of kindred groups were first formed for food supply purposes. A plentiful food supply and improved tools permitted people to settle permanently in villages. Land ownership became a part of a cooperative family venture, after which is when the structure began to change from matriarchal (mother) to patriarchal (father), or the "Father-Right" family of today.http://www.nbufront.org/html/MastersMuseums/JHClarke/WorldHistoryOverview/Chapter2.html