Common ancestor

Definition and stakes

Portrait of Lewis Henry Morgan Lewis Henry Morgan Ancient Society

The gens embraces a part only of the descendants of a supposed common ancestor, and excludes the remainder; it also embraces a part only of a family, and excludes the remainder. In order to be a constituent of the gens, the family should enter entire within its folds, which was impossible in the archaic period, and constructive only in the later.
Source: Gutenberg

Eliza Burt Gamble The Sexes in Science and History

The natural way in which a tribe is formed is from a family or group, which in time increases and divides into many households, still recognizing one another as kindred, and this kinship is so thoroughly felt to be the tie of the whole tribe, that even when there has been a mixture of tribes, a common ancestor is often invented to make an imaginary bond of union.82
The gens, until a comparatively recent time in the history of the human race, was composed of a female ancestor, all her children and all the children of her daughters, but not of her sons.
Source: Gutenberg

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