9700–5500 BCE: (Food Production and Its Demographic Consequences — The Increasing Reliance on Food Production Giving Impetus to Human Population Growth Which…

9700–5500 BCE: (Food Production and Its Demographic Consequences — The Increasing Reliance on Food Production Giving Impetus to Human Population Growth Which Led to the Need for More Land, Food Production’s Greater Productivity per Unit of Land Allowing Enlarging Cultivator and Herder Populations to Spread More and More Widely Outward from Their Original Areas, and the Spreading of People into New Lands Carrying Their Languages with Them, the Protolanguage Gradually Diversifying into Arrays of Distinct Descendant Languages as Changes Accumulated in Different Regions): A common world historical feature of the increasing reliance on food production was the impetus it gave to human population growth. The growth in population soon led, in consequence, to the need for more land, while food production with its greater productivity per unit of land allowed the enlarging cultivator and herder populations to recurrently spread more and more widely outward from their original areas. And the spreading of people with their new forms of subsistence into new lands had a further consequence: when people in those ages expanded into new areas, their languages spread with them. In the regular course of language history, as the centuries pass, more and more changes accumulate in how those languages are spoken — in the meanings of existing words, in the adoption or coining of new words, in the grammar rules, and in the ways that people pronounce the individual sounds of the language. The original language — the protolanguage — of the carriers of the new ways of subsistence changed, with different particular changes taking place in each of the different areas of population spread. As the changes accumulated, mutual intelligibility gradually broke down, giving rise over many centuries to an array of distinct languages all descended from that original tongue. This is the engine that built the linguistic map of the world. Food production created population growth. Population growth created territorial expansion. Territorial expansion created linguistic diversification. And the patterns of that diversification, preserved in the family trees of the world’s language families, serve as a historical archive of the expansions themselves — telling us who spread where, when, and with what economic innovations. The great language families of Africa — Niger-Congo, Nilo-Saharan, Afrasian — are not merely linguistic categories. They are the fossilized records of demographic explosions driven by food production, each family tree a map of human expansion written in phonemes and morphemes rather than in stone or clay.