One word for father-in-law dates patriarchy to 4000 BCE

Proto-Semitic was spoken around 4000 to 3800 BCE in the region of Syria, Palestine and Israel. In that language the word for father-in-law comes from the much older proto-Afroasiatic word for father's brother. A shift like that records a fact about households. It happens where a man's father-in-law usually is his father's brother, which is the marriage rule anthropologists call preferential parallel-cousin marriage. That rule concentrates marriages inside the paternal line, keeps property and loyalty there, and turns up again and again alongside strongly patriarchal social structure. So one semantic change dates the arrangement. Strong patriarchy among Semitic speakers is at least six thousand years old. It was in place while cities were emerging along and inland from the eastern shore of the Mediterranean, and it predates the large states of the region by a millennium. When those states arrived they formalised an order that was already running, which is what states generally do.

Barrera-Mordan, in the Dominican Republic, is one of the sites that forced archaeologists to move the date of human arrival in the northern Caribbean. The material there is a stone-working complex built on flaked tools struck from cores, and it dates to around 4000 BCE. The people who made it belong to what is labelled the Lithic age. They had no pottery, and they should not be confused with the ceramic-producing groups who reached the islands thousands of years afterwards and are far better known. What the assemblage records is a specialised adaptation, worked out for a set of islands with particular stone, particular coastlines and particular food. Sites like this are how the initial migration routes from the surrounding mainland get mapped, because the tool types are the trail. Hispaniola, the island Haiti shares, was inhabited about six thousand years ago by people who knew exactly what they were doing with rock.

Copper was in use before anyone learned to smelt it. It occurs here and there as native copper, relatively pure pieces sitting inside the ore, and those can be hammered cold into shape. People did this in several parts of Africa and Eurasia, and the makers of the Old Copper Complex around the North American Great Lakes were doing it six thousand years ago. Getting metal out of ore is a different problem. It needs sustained high temperature under control, and in every region where it happened, smelting arrived only after ceramic technology was already known there. The kiln comes first and the furnace follows. That dependency has a consequence worth stating plainly. Ceramics were invented independently in Africa, among the oldest anywhere, by communities in the Sahara. The technology that made a fired pot possible is the technology that eventually made a smelter possible. Bronze and iron both rest on a foundation laid by potters.