Demography Lecture # 4: Historical Population Patterns and Processes with the Spread of Agriculture and Nomadic Pastoralism
The fourth GeoCurrents lecture on global demography has been uploaded on YouTube and can be found here. It examines population issues that arose after the development of agriculture, as well as those following the initiation of horse-based nomadic pastoralism. It first looks at the spread of neolithic farming into Europe, noting that the expanding agricultural populations largely replaced the preexisting hunter-gatherers, who were evidently restricted to a few areas in which crop-growing was not feasible. It then turns to the oddity of the resurgence of genetic material from hunter-gatherer peoples that occurred in the later neolithic period in Europe around 4000 BCE. The argument is then advanced that new agricultural populations usually overwhelm hunter-gatherer population in areas conducive to farming, but that hunter-gatherers sometimes expand out of such “refugia” into much more densely populated agricultural areas, where they invariably take up agriculture themselves. Three examples are then discussed, using historical linguistics as the primary base of evidence. Two first two look at instances of the spread of farmers and the retreat of hunter-gatherers: the Bantu expansion in Africa and the Austronesian expansion in Southeast Asia, the Pacific, and the Indian Ocean. The third example looks at a hunter-gatherer expansion into an agricultural zone, that of the Uto-Aztecan-speaking “Chichimeca” people who pushed into Mesoamerica and gave rise to the Aztec Empire.
The next part of the lecture turns to population crashes that sometimes occurred in early agricultural societies, whether from disease, weather fluctuations and climate change, soil erosion and environmental degradation more generally, or the violent influx of new human groups. The main example investigated is the decline of European populations in the late neolithic, which was marked by decreasing health, the appearance of the bubonic plague, and the arrival of Indo-European-speaking peoples with a partly pastoral way of live. The lecture ends with a discussion of the population surge and geographical expansion of the early Indo-Europeans, who had created a new way of life in Central Eurasia centered on horse-based nomadic pastoralism.
