How did Morgan explain the evolution of marriage, family and Socio-Political organization, and how did other evolutionists disagree with his explanation?

Morgan’s sequence

• He used Iroquois kinship and classical texts. Kin terms were fossils of older marriage.
• Family ran from promiscuity through group marriage, punaluan, pairing, and monogamy, tied to property.
• Polity ran from gens (clan) to phratry, tribe, and the state of property and territory, as in Rome and Greece.
• Savagery, barbarism, and civilisation were marked by inventions: fire, bow, pottery, agriculture, iron, writing.

Disagreements among evolutionists

• McLennan put bride-capture and female infanticide first, and doubted Morgan’s group marriage as a real stage.
• Lubbock and Spencer kept progress but stressed religion or military-industrial types more than gens.
• Bachofen had already put mother-right first. Morgan used matriliny as an early gens, which Maine patriarchy contradicted.
• Tylor shared unilinear culture but worked from animism and survivals, not from Iroquois terms as law.
• Engels accepted Morgan and tied the monogamous family to private property. That political use later drew ethnographic fire.

Later evolutionary critique

• Boas and Lowie showed clans, states, and marriage forms do not travel in one world order.
• Maine’s status-to-contract still differed: Roman law, not Iroquois, was his engine.
• Field cases of Australian sections and African states broke the single gens-to-state story.