Cicero once said that to be ignorant of what has come before was to remain a child, and our world today we face many challenges as documentaries like Mission Blue and Racing Extinction illustrate: climate change, ocean acidification, mass extinction and the like which points towards a grim Malthusian outcome. However these documentaries always hold out hope that it can change with adaptations made to prevent this outcome, and as can be seen with the meeting of world powers in Paris there is an effort to make those changes. Yet without a full understanding of the process behind these effects, the driving cause cannot be addressed. To understand the origin of agriculture is to find those factors which led to that adaptation and the forming of our modern world system.
To achieve a unified theory for the origin of agriculture differing theories need to be considered. For this paper, the work of David Rindos and Mark Cohen will form the bulk of discussion, however their views are informed by other works and there is further evidence to be brought in. Their theories are not without their flaws, but unlike Rindos tends to do, theories will not be thrown out wholesale on the basis of these flaws, but rather the good aspects of the theories will be used to form a stronger whole.
In the early days of anthropological thought, theories for the origin of agriculture were often influenced by racist and colonial ideology of the time. These theories hinged upon the idea that the life of hunter-gatherer societies were desperately hard lives one step away from starvation and that agriculture was an invention or discovery that lifted humanity from this state to a better life. Hand in hand with this was the concept of a progression of societies as set forth by Hegel and others in which Europe’s commerce driven societies were the highest order. These views helped to prop up Europe’s colonial expansion and slave trade; it wasn’t exploitation, they were bringing the ‘gift’ of Europe’s advanced society to these people. While these theories have largely been discredited they still linger, particularly the invention/discovery model for agriculture. Despite all the flaws in this model it can still not be completely thrown out, for human creativity did have an impact on the origin of agriculture, not in one people or one location, but in a range of adaptations, from irrigation and fertilization to the use of terracing the sides of mountains to make more farmable land, it has been the creativity of humans that has allowed the continuous expansion of the species population.
One of the major reasons the invention/discovery model was replaced was the work of Marshall Sahlins which showed that hunter-gatherers were the original affluent society. By showing this culture to be one of greater leisure with abundant food and a more varied diet compared to agricultural societies, it dismantled the notion of agriculture as the empowering facet of human life and recast it as a burden, which begs the question why would humans take up this burden and move away from the mode of life which their evolution had taken place in; the answer to which is that some causal pressure necessitated the change. Yet the resources to make that change would have already needed to be present by the time the pressure required the change.
Those resources were present because humans and plants have been co-evolving, as all plants and animals do naturally, from the moment the human ancestors emerged roughly 300 thousand years ago. This is Rindos’ theory based on Darwinian evolution. It is not without its flaws, Rindos does not attach his model to a time line, he pays attention to feeding habits instead of the full use of plants by humans, and he disregards environment completely (temperate, tropical, etc), he also offers no explanation for the nearly simultaneous adoption of agriculture on a global scale. Rindos absolutely rejects any agency in the origin of agriculture but fails to address the glaring weakness in this view: why didn’t other animals, such as other primates with their monkey gardens, also co-evolve into agriculture? Despite these weaknesses, Rindos’ model is still beneficial, and when adding information from Anderson’s Dump Heap theory and Lathrap’s data regarding the spread of bottle gourds it provides an excellent model for co-evolution.
Rindos lays out three stages in the co-evolutionary process. With incidental domestication people eat food such as fruit and then spit out or defecate the seeds into their anthropogenic landscape. These plants then began to evolve in this landscape which was enriched by fire ashes, manure, and the limited plowing effect of foot traffic loosening the soil in the area. When specialized domestication occurs (Rindos does not provide a timeline, but likely 20 to 10 thousand years ago during the Broad Spectrum Revolution) humans began to offer intentional assistance to plants such as protection from predation and destruction of undesired competitors. Agricultural domestication, occurring roughly 10 thousand years ago featured an intensification of aid and protection to desired plants, including clearing land, weeding, and irrigation. Of course the settlement ecology of these humans would include more than just food, and this is where Anderson’s work can better inform Rindos’; plants used for medicine, building materials, firewood, and ornamentation would have all come into the anthropogenic landscape. Lathrap’s data showing the spread of the bottle gourd around the world reinforces the idea of the dump heap and proves that plants can be transported and maintained during periods before the advent of settled life and agriculture.
For all its strengths, the co-evolutionary model does not provide a convincing argument for why humanity would change its roughly 290 thousand-year-old way of existence. Nor does it offer a compelling reason for why this change would happen all around the world at roughly the same time. For this we will need to pull in another theory to add to the unified perspective.
Mark Cohen was not the first scholar to suspect population growth as a cause for agricultural adaptation. Often population and environmental change were combined, such as when Childe proposed a model where drought conditions forced the population into river valleys and oasis areas, or Binford who suggested rising sea levels caused conflict in the interface of the coastal and inland region. In this line of thought too is Malthus and Harris who have negative views of population growth and adaptations to extend that growth. But Cohen was the first to view population pressure on a global scale. It is here that can be seen the impetus for the change in the human mode of life.
There are some flaws with Cohen’s theory: It does not properly examine the co-evolution of plants and humans. It does not seek to explain why human population has been able to grow so rapidly. For the first we bring in Rindos et al. For the second we must point to the sexual division of labor, which includes sharing as a component, as the prime factor. No other species has these traits in the same manner, and none have had the reproductive success of humans.
Cohen argues that humans spread out as their population grew, the ‘pioneer foragers’ that Darwin had theorized. They spread throughout Africa, then approximately 90 thousand years ago they began to migrate globally until they became environmentally circumscribed, with no more land to spread to. This also resulted in social circumscription, being surrounded by other groups of humans which prevented moving to new foraging grounds without intraspecific competition.
The constraints on foraging and the continued reproductive success of humans resulted in the Broad Spectrum Revolution roughly 20 thousand years ago marked by more settled life and the use of aquatic resources for food, such as shellfish and fish. The continued demographic pressure by perpetual reproductive success led to the adaptation of agriculture globally starting around 10 thousand years ago. In a brief period of time agriculture becomes the way of life for most humans in the world, and by 7 thousand years ago intensive agriculture is underway.
These changes also prompted cultural evolution in human societies. Reciprocal gift giving is replaced by redistributive systems and ‘big men’ which leads to specialization and social classes, to trade and markets and eventually the modern world system with its global market. In a few especially resource-rich areas like the Pacific Northwest and Australia, intensification had not led to agriculture by the time of European colonialism but had led to these same cultural evolutions. These societies could have their ritual forms corrupted by contact with outside cultures as seen in the Potlatch ceremonies of the Pacific Northwest.
There has also been cultural adaptations to this demographic pressure. The Tibetans not only used creativity, as was discussed before, to make inhospitable environments livable and arable but also resorted to cultural conventions such as fraternal polyandry to preserve land within the family. Europeans also adopted cultural adaptations to preserve land with the convention of primogeniture where the firstborn son inherited everything. More recently the Chinese adopted a one-child policy in an effort to control their population growth that was recently abandoned due to its many faults.
There is also one major obstacle to our unified view of the origin of agriculture, and that is Homo erectus. They were the first Homo species to migrate out of Africa roughly 1.9 to 1.6 million years ago, and neither Rindos nor Cohen addresses them. From archaeological evidence, the species never made it off the African and Eurasian continents. If once they reached the landbound environmental circumscription, they were unable to make the adaptation to agriculture and had a population crash, this would put the nail in the coffin for Rindos’ rejection of intent. However if Homo erectus had been able to hang on throughout the continents, it would have provided significant resistance for the expanding Homo sapiens, and damage Cohen’s model of expansion to avoid competition. This is an area that requires further research.
From this it is evident that human reproductive success and demographic pressure is the driving force behind humanities’ ever increasing demand for resources. This process of intensification has reached a point harmful to the entire global environment and in order to address the intensification this needs to be understood. GreenWave recently won the Fuller Prize for its vertical aquafarming model. This idea seeks to promote safe, beneficial aquafarming that doesn’t harm the environment. When simply looking at how to provide more food, this seems like a great idea. If the pressure behind that requirement for increased resources isn’t considered, then things like the rapid privatization of the ocean floor, loss of biodiversity in the ocean, increased shipping traffic to transport food, and more areas of intraspecific competition may have unforeseen consequences.
In a unified perspective, human reproductive success as a result of the sexual division of labor and sharing caused the species to spread out globally to avoid competition. Once environmentally and socially circumscribed, continuing demographic pressure led to an intensification of resources, first from aquatic sources and then taking the desired plants well suited to human settlement ecology and through human creativity transitioning to agriculture. Rindos’ theory is important as it explains how those desired plants came to be available for that transition. Humanity with its change to settled agricultural life began a process of cultural evolution resulting in our modern world system, which is still driven largely by the intensification demanded by the continued reproductive success of the species.
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