Lecture 4 - Agriculture and Disease in History

Agriculture and the Environment

• Competition for resources = warfare = replacement of priesthood by warrior-kings

• One of the earliest? Sargon of Akkad (warrior, king, lawyer, conduit to the gods)

• Why? Because agriculture has become complex and needs a complex governing hierarchy →one that controls irrigation, food distribution, etc.

The River Flood Phenomenon: Blessing and Problem

• Mesopotamia = “land between rivers”; the land of Summer and Akkad (ca 5,500 BP to 4,000 BP)

• Tigris-Euphrates: flood March to May

• Crops already in fields, need protection

• Nile: floods Sept-Oct

• Crops off fields, soil fertilized for next year

Mesopotamian Irrigation & its Problems

• Very old, at least 8000BP

• Requirements: protect crops early, water them later

• 4500BP: crop yields falling because of salinization

• Regional productivity damaged, cycles of social collapse follow; Summer collapses around 4000BP, being replaced by Assyrian entities from the northwest

The Tragedy of Development: Egypt’s Case After WWII

• First dam at Aswan on the Nile, some 800km south of Cairo, finished in1902

• 1950s: Gamal Abdel Nasser, the Egyptian president, envisions the construction of a new dam at Aswan, ending the river’s flooding and producing hydropower for a growing economy

• 1960-1970: dam built against the backdrop of the Cold War; formally opened in 1971

Problems with the Dam (almost immediate)

• Loss of fertility in the Nile Delta (no more nutritive silt deposits by floods also enhances erosion of the delta too…very bad news in a climate-changing world)

- Egyptian farming community now dependent upon external sources of fertilizer (1 MT/yr), where before there had been independence

• Collapse of fish stocks in the Nile itself (many were migratory and the dam prevents their journey) and the dramatic reduction in the anchovy/sardine population & fishery in the Eastern Mediterranean

Agriculture in SE Asia: the Great Leap Forward

• Prehistoric patterns similar to those of Middle east…by 5500BP: wheat, millet, rice are being grown on arable land

• 2500BP: a great conceptual leap - get the rice wet in Paddy (padi) Fields; by 1500BP this is a common practice throughout SE Asia

Advantages of Aquaculture

• Deals with soil fertility problem:

- Water is nutrient-rich

- Algae can grow in it, fixing nitrogen

• Secondary benefit - yummy crustaceans and small freshwater fish ( and, hence, and easily-obtainable dietary protein source)

Drawback: It’s a Horrifically Labor-Intensive Process

• Rice-paddy farmers employ 26 or more management techniques

• Rice stalks are planted individually!

• Knowledge base required for aquaculture is also enormous

Another apparent drawback: it’s a totally transformational process

• Rivers dammed, flow controlled, etc.

• Slope management and terracing

• Entire ecosystems realigned to artificial forms

• Methane production from wet-rice cultivation is evident in ice cores (but there is a “but”)

• Hidden benefit: there’s almost no further impact

Implications for History

• Aquaculture is incredibly efficient → so population rises a lot

• China in 1200 was most advanced country in the world. Then it stalled. Why?

• Got to keep people in the land → no social mobility!

• Failure lies in efficiency’s success: there’s no need to innovate

• In Europe, the opposite was true…they became restless technophiles

“Less Advanced” Agriculture and its Impact: NW Europe

• Slash-and-burn agriculture, relying on rain for water

• Cyclical process replaced, about 3800BP, with settled permanent agriculture

• Problems?

- Soil erosion (how do we know?)

- Species extinction (because they’re not there anymore) and those species’ replacements

• Diet doesn’t change that much, implying that agriculture probably failed often and required supplementary food sources

Agricultural Life in “Dark Ages” Europe

• During the period of the Roman empire (ca.2000-1500BP) life was cosmopolitan and interconnected; after Rome’s fall Europe enters the intensely local Dark Ages or Mediaeval period

• Manors (North) and Villas (South) became the focus of agriculture existence, not individual farms → Agriculture was based on these self-sufficient, intensely local and isolated communities

Medieval Agricultural Production

Four main factors determine its nature:

• Economic self-sufficiency of manor

• Development of mixed agriculture

• New technologies

• Land tenure and ownership

Organization, Technology

• Land-holdings, divided into strip fields, affecting production

• Technological change also affected production…the heavy plough and horse collar were critical adaptations

New Lands, New Crops

• Middle Ages (ca. 900-1300) see more land coming under cultivation: where?

• New crops too - sugarcane, rice, cotton, fruits (all from contact with the Arab world)

• Ca. 900-1280, during the Mediaeval Warm Period there’s a significant increase in farmed land area, and therefore lands that are cleared

Mediaeval Food and Diets

• Depended a great deal on the social class of the individual:

- The Wealthy: had a wide range of foods available to them

- The Poor: had to make do with a very simple, calorically-limited diet

• Most common drink? Ale, not water

• Most diets were protein-poor and amalgamated (e.g., “pottage” and “potluck” meals)

• The premodern world was usually a hungry one - and that’s when times were good; when times were bad, they were bad

Agricultural Conclusions: Life on a Knife-Edge

• For most (almost all) of the pre-modern period humanity lived on a knife-edge…

• …agriculture was a great invention, but for most of the world it was still limited and not hugely productive

• Nevertheless, the conditioned our societies - their politics, philosophy, economies, etc.

• And it allowed for environmental modifications, generally on a small but gradually expanding scale

Disease in Pre-Agricultural Society

• Disease not common amongst hunter-gatherers. Why?

- Low population densities limit disease spread

- Absence of domesticated animals

• Infections that did occur resulted from trauma or from zoonosis

Disease in Agricultural Society

• Infectious disease arose because of the agricultural revolution

• People lived much close to one another

• Animals being consumed changed

• Diets changed, became carb-heavy and lowered resistance to disease

• Disease itself became the major limiter of population

Epidemics as Phenomena in History

• As trading and social expansion occurred, diseases also became transmitted by human carriers

• Paradoxically, countries that traded a lot suffered few epidemics; those that traded little suffered serious epidemics

The Plague: Origins and Spread

• Originates in Central Asia, spread to Europeans by germ warfare (yep!)

• 1347: arrives in SE Europe, spreads from there

• Mortality rates varied from 15-65%, for a continental average of 33-50%

Plague: Pathogenesis

Flea drinks rat blood that carries the bacteria → Bacteria multiply in flea’s gut → Gut clogged with bacteria → Flea bits human, regurgitates blood into open wound → Human is infected →

(There is a definite environmental dimension at work here also: instability in the European climate, beginning around 1300, probably contributed to the disease’s spread – note that this instability is the onset of the L.I.A.)

Official Reaction and Opinion

• Not divine, but disease

• Control measures generally failed, though

• Wild, crazy speculations for cures abound → esp. the “bad smell” theory

• What the academics said…(not much use)

Population and Economic Impact

• 1 in 3 of everybody dead!

• Mortality patterns uneven, though: some areas harder hit

• Post-plague, urban areas recover quicker than the countryside

• Economic disruption nearly catastrophic (I mean, think about it!)

Pre-Modern Methods of Combatting Disease

• Quarantine – 40-day isolation period (no real science behind it)

• Sanitation – especially the provision of clean water and the disposal of waste

• Other Measures – church bells, burning pitch, whitewash, gunfire, “posies”, thinking “good thoughts”, you name it – but not, generally, appeal to God (or the gods) for forgiveness. Help, yes; forgiveness, no.

Sanitation

• “Cleanliness is next to Godliness” – an idea shot through many religious texts (including the Old Testament)

• Physical sanitation (sewers, baths, etc.) was from very early on a measure of a civilization’s, well, civilization

Western Medical Science Catches up to Disease

• 1795 – Alexander Garden and Charles White identify filth as causal in some post-partum disease

• 1854 – John Snow demonstrates the link between contaminated water and cholera

• 1870s-1880s – the Chadwick Report produces noticeable improvements in sanitation

• Vaccination also played a huge role in the attenuation or elimination of certain diseases (eg Smallpox)

The Changing Face of Disease in Modern Society

• The diseases that’ll probably kill you (sorry, it’s true) are not the ones that killed your great-great grandparents

• 1900? Strokes, heart attacks, cancers, diabetes? → all pretty much unknown

• 2000? Industrial diseases are common killers today, esp. the cancers and body imbalances (type II diabetes, sclerosis, hypertension) that are probably a consequence of our highly chemicalized environment

The Weight of Numbers…

• World population reached 6 billion in Sept 1999 (it was only 2 billion in 1930); it reached 7 billion in Oct 2011, 8 billion in Nov 2022

• Ca. 250,000 added every day (that’s about a Halifax every day or two)

• Ca. 90 million-plus per year (a Vietnam or Philippines per year)

• In the next three years or so – a new USA population will be added to the planet…can we cope?