The History of Agriculture (I)

Before I delve into the specific mechanisms of the interaction between agriculture and our climate, I thought I should understand more about the origins and evolution of agriculture through the years

So in a 2-part series, here's a flash through agriculture in the past 10,000 years…

Part I : Origins of Agriculture

Where did Agriculture emerge?

It emerged in various locations across the globe e.g. Near East,  China, sub-Saharan Africa, Mexico, Easter U.S..   The interesting point here is that they all emerged at roughly the same time. This is allows for the many theories as to why they emerged as we will see below...

When did Agriculture first emerge?

It is estimated that even although cognitively modern humans have existed 50,000 years ago, yet the most recent evidence of agricultural practices occurred only around ~10,000 years ago. Since the immediate physical and cognitive development of humans were not the cause of agriculture, what then triggered the transition from a hunter-gatherer lifestyle?

Why did Agriculture emerge?

Universal stress-related triggers:

Climate Change

#1:Transition out of the ice age (Richerson et al., 2001)

 Several scientists postulate that origins of agriculture should round about coincide with the start of the Late Glacial Period prior to the Holocene (the Holocene is the current interglacial we are in which began 11.5-11.6 (cal) ka BP). This period was characterised by warmer, wetter and more stable conditions which enabled the domestication of plants and animals i.e. agriculture.

Evidence #1?

There is a gap here as evidence. The first evidence of agriculture was not found during the first 2000 years of  warming after the Last Glacial Maxima. Instead it occurs only much later. Hence some experts subscribe to this other view…:

#2: Oasis Hypothesis  (Childe, 1930s)

Other Scientists postulate that it was instead because of the harsh conditions that occurred in the Younger Dryas (sudden cooling/ climate reversal during the warming) that humans were relegated to remain in more hospitable locations. The concentration of humans in these areas (i.e. labour for agriculture) and unfavourable hunting and gathering conditions were probably what sparked the transition to agriculture.

Evidence #2?

The first evidence of agriculture coincides with this period. This was a worldwide climatic event, supporting the observation of independent transitions worldwide at the same time.

Technological Innovation

Akin to "Light-bulb invention" (E.g. Olsson and Hibbs, 2005):

There was relatively sudden invention of technologies due to improving climatic conditions which led to satiation and hence energy and time aside from fighting for survival. These technologies allowed humans to explore the realm of domesticating of crops and animals.

Evidence?

This theory does not account for the similar time but independent locations of the first instances of agriculture. 

Population Boom:

Population Pressure Hypothesis (E.g. Cohen, 1997):

The population was growing so large that it was putting pressure on the resources available in the wild. This was a worldwide phenomena.

Evidence?

There was no sign of decreasing standards of living for prior to the advent of agriculture (i.e. no pressure)  and the population on Earth then was relatively small. While this is a possibility, the transition could have very well occurred otherwise.

Universal stress-free models:

Social Models: (E.g. Cauvin 2000 & Haydn, 2003)

This theory occurs based on the assumption that the origins of agriculture occurred in a time of abundance. The move towards agriculture was hence a manifestation of the innate tendency to attain self-actualisation or self-aggrandisement.

Evidence? (Regional)

In the Near East, there was no evidence of complete domestication during the Younger Dryas. Instead, there were Natufian communities remained as hunters and gatherers. Hence the need for alternative explanations like this.

Some thoughts on the above:

Although it is unclear which was the fundamental factor that sparked the initial transition, it is agreeable that without the favourable climatic conditions, it would not have been possible for agriculture to be sustained thereafter. The unfavourable conditions of the last glacial period/ ice age (100 to 11.5 Ka) prevented any form of agricultural activity (e.g. temperature and atmospheric CO2 concentrations were low) and  would have probably rendered agriculture unfeasible even given other triggers or factors. Instead, following the Younger Dryas, warming continued allowing the favourable conditions facilitating the expansion of agriculture. Propagating this more productive form of food production also meant a more stable food source which would allow greater population expansion. The productivity of agriculture was also enhanced by another positive-feedback: the domestication of animals also meant the concomitant selection of animals with more productive traits. From this point forth, humans didn't look back and agriculture became the dominant and, as several Scientists have put it, "compulsory" food source.

Still, the conclusion by Zeder & Smith (2009) makes sense to me (especially in light of recent evidence showing nuanced differences between the locations) that it is probably inadequate to assume a single causation for the advent of agriculture (although some factors might be more consequential and far-reaching than other s e.g. climate).  Rather, it is probably a result of macro- and micro-scale factors: common broad factors which nudged the move but different strategies employed which were tailored to immediate conditions.

For me, this brief investigation into the origins of agriculture sets the stage in giving us insight into the multi-factorial nature of agricultural systems and it is inadequate to analyse the past or predict the future of  these systems based on a certain factor. This reveals that if any favourable change is to be made, it will need to muster the will and knowledge of experts and peoples from all areas of society. In addition, strategies that are hailed as the solution to 'the world's problems' must be treated with caution due to the extremely variable environmental, social and political conditions worldwide that are sometimes overlooked.

In so far as this blog aims to view agriculture from the environmental perspective, it would also like to view the solutions in its wider context and complexities (And that, I will leave to a later date to for further discovery :))

Coming up…!

History of Agriculture (II): Evolution of Agriculture through the years. How did agriculture get to where it is now?

References:

1. Dow et al.  August 2005.  The Transition to Agriculture: Climate reversals, population density, and technical change. http://www.sfu.ca/~gdow/download/agriculture805.pdf

2. Zeder & Smith. October 2009. A Conversation on Agriculture Origins. Current Anthropology. http://anthropology.si.edu/archaeobio/images/zeder_smith_crowdedroom2009.pdf
(If interested, a fellow blogger, Rob shares his thoughts on this article here: http://robs-agriculture.blogspot.co.uk/2011/10/agricultural-origins-roots-of-change.html)