Spread of Farming, New Diseases, and Rising Civilizations: Mid- Holocene Optimum

• Main Author: McMichael, Anthony
• Format: Book Part
• Language: unknown
• Published: Oxford University Press 2017
• Subjects: Ice Sheet; Tundra
• Online Access: http://dx.doi.org/10.1093/oso/9780190262952.003.0010

As The Earth Warmed after the last glacial maximum, temperatures fluctuated. About 9700 B.C.E., temperatures rose again suddenly and began to stabilize, marking the beginning of a new geological epoch, the Holocene. The landscape continued to change, but not so fast that a single generation of humans would have noticed. Ice- sheets and tundra were receding in Eurasia, and over time human groups, both hunter- gatherers and then early farmer- pastoralist communities, adjusted their ways of living to warmer conditions and different rainfall patterns. Small- scale farming and herding emerged on all nonpolar con­tinents during the period 8500 to 6000 B.C.E., predominantly in the northern hemisphere, while human numbers were creeping up. These great changes in environmental conditions and subsequent cultural practices had a profound influence on the foundations of human health and survival: food sufficiency and quality, water sup­plies, contacts with infectious agents, modes of settlement, and social relations. A new era in human ecology was looming. Farming increased food production, but the switch to dependency on a few staples decreased diversity of diets and created an annual agricul­tural regime more susceptible to climate shifts. Close contact with animals, standing water in irrigated environments, and denser set­tlements provided opportunities for microbes, pathogens, viruses, and parasites to cross species barriers and infect and spread among human populations. During the Early Holocene, from about 9700 B.C.E. to 6000 B.C.E., the earth was subjected to the competing stresses of high solar influ­ence and still massive melting ice- sheets. From around 6000 B.C.E., the majority of ice- sheet melting had abated, allowing the stabiliza­tion of the Earth’s climate into what can be called the Mid- Holocene Climatic Optimum (approx. 6000 to 3000 B.C.E.). This was a change in climate that spanned 3,000 to 4,000 years. Warming was most evi­dent in the northern hemisphere, influenced by the peaking of solar radiation at ...