The Origins of Agriculture: The Neolithic
Development of agriculture
By about 10,000 years ago (8000 B.C.) glacial conditions had largely given way to more temperate conditions. Temperatures were rapidly warming, with wetter conditions common throughout most of Europe and the Americas. This prompted the expansion of forests, which brought with a wide range of more forest adapted animal species and a broad range of grasses and other plants (nuts, berries, etc). It also was a time when sea levels had risen isolating continents (Australia, North America) and islands (while also forming islands in low-lying areas).
For humans and their lifestyle this meant a major change. Traditional sources of food (e.g., large mammals) were only found, if at all (due to extinction), in more northern latitudes, and many plant species also become less common with the expansion of forests. Culturally this period preceding the extensive reliance on agriculture is called the Mesolithic (Middle Stone Age) in Europe and Asia, and the Archaic in the Americas.
During the Mesolithic and Archaic people exploited a range of environments, from which they obtained many different species of plants and animals (called broad spectrum foraging), some of whom were closely related to those that became important sources of species for agricultural communities.
The Neolithic (New Stone Age) differs from the Mesolithic and Archaic periods in the way people organized their lives. Rather than exploiting a wide range of marine and terrestrial wild resources, many communities came to focus on fewer species, doing so in a more intensive manner. This was possible only through the adoption of agricultural practices.
This Neolithic transformation is
referred to as the process of domestication: this ishuman-influenced
biological changes in physical (and hence genetic) characteristics of plants
and animals, which result in plants that become reliant on humans for propagation,
and animals that become dependant on humans for reproduction, food and water.
This process is a gradual one, and varies in necessary effort according to the
species (e.g., some animals are easier to herd, or some plants easier to exploit);
however, it always involves human interference in the species ability to gain
nutrition and to reproduce.
Plants
Whether by accident or design, individuals or groups selected those plants which had characteristics they preferred, resulting in the ongoing selection of those characteristics in subsequent plant generations. For grasses this would have meant a preference for those less prone to easy seed dispersal (i.e., those that would not lose a substantial portion of their seeds to wind or other activity prior to harvesting; see Price and Feinman, pages 197-198), and also those that had higher productivity per plant. The consequence of this selective process was domesticated plants, which have come to have a central place in most human societies around the world.
The earliest plant cultigens
were seed crops: grass species that produce seeds which are high in carbohydrates
and easy to store for long periods. Another important plant group domesticate
were tubers or roots (e.g., taro, yam, manioc, potatoes). However, it is difficult
to distinguish domesticated root varieties from their wild relatives due to
the pattern of asexual reproduction, and hence they are difficult to clearly
identify in archaeological sites. The process of clearing and preparing the
fields, weeding, watering and tending the plants is called cultivation.
Animals
The domestication of most animals appears to have been initially focussed on protein (meat) potential, though the first animal domesticated, the dog (by 14,000 years B.P. in the Old World), may have been used for hunting, and perhaps less for food. Domesticated animals also become important for their labour potential as field workers (e.g., cattle, horses) and beasts of burden (e.g., cattle, llama), in addition to their value as sources for other products like wool, leather, dairy products, and manure. This pattern of maintaining animals is referred to ashusbandry.
Animal domestication also involved a deliberate or accidental selection for preferred characteristics, with a focus on those species which were by their nature more social or herd-like (in association with their other identified values listed above). A consequence of this interference was that domesticated animals tend to be smaller than their wild ancestors, and be easier to control. Herders controlled breeding by separating males from females, and selecting specific individuals for breeding over others (similar to what breeders continue to do today in the cattle and sheep industries).
In both plant and animal species
there was potential for food storage: plants in the form of seeds and tubers,
and animals as available meat providers, as well as associated parts such as
wool, milk and hides.
Pro and cons of agriculture
Potential pros:
It allows (and requires) people
to be more sedentary (i.e., maintain more permanent seasonal or year-round houses),
as fields and herds require tending and some degree of continuous maintenance.
Agriculture and herding tend to provide greater food productivity, at least
in quantitative terms, than is generally possible with a broad spectrum approach.
Also, this productivity can be stored during non-growing seasons, providing
a reliable source of food for most or all of the year. Due to this pattern of
reliable food and greater sedentism, individuals and groups may be able to undertake
non-agricultural activities and occupations (e.g., craftspeople, traders, religious
specialists, etc.).
Potential cons:
A concern with a heavy reliance on
a small number of food sources is that if one or more fails (e.g., caused by
disease or drought), then other sources may not be available to fill the gap
when stored foods are relied upon. Sedentism tends to lead to larger populations,
and thus more potential for the spread for contagious diseases. Also, where
there is variation in land quality and access to resources such as water, inequalities
among and between agricultural communities may develop, perhaps causing or as
a consequence of increased competition.
Evidence for agriculture
Possible markers of agricultural behavior: sedentism (e.g., sturdier, more permanent houses) and larger communities; evidence for ground-stone lithic technology (pestle and mortar, axes, hoes), storage technology such as pottery.
Strong evidence for agriculture: fields and their soils, ecofacts such as pollen, seeds, preserved plant remains, and animal bones, plant residue on artifacts, specialized artifacts or features (e.g., storage buildings).
There are several shared cultural patterns associated with the process of domestication and more broadly, the impact of agriculture during the Neolithic (see pages 253-255 in Price and Feinman). These tend to have their origins within the European and Asian Mesolithic or North American Archaic.
1. Sedentism becomes reinforced, due to the necessity to tend the growing crops, or to control the animals; i.e., people stayed in one place during the growing season and perhaps longer, on a more permanent basis.
2. Storage becomes more important with more permanent sedentism and agriculture. Harvested crops require storage, which may be provided by separate buildings (e.g., granaries), storage pits, clay, stone or organic storage (thus pottery becomes more significant).
3. Tools based on ground-stone technology appear in greater frequency and become central to the domestic tool kit (pestles and mortars, querns), as well as for clearing land (axes, adzes) and tilling fields (hoes).
4. Neolithic communities show increases dependence on domesticated plants and animals, with a concurrent decline in wild animals and plants.
4. With sedentism and the reliance on fewer species, greater human population size and density leads to greater potential for contagious diseases and nutritional problems resulting from poor harvests, lost storage, etc. In general, agricultural communities show more health problems and a reduced lifespan, relative to earlier hunter-gatherer groups.
5. Neolithic communities show more
evidence of the movement of localized raw materials or processed items across
the landscape. The exchange of materials such as shell and stone (e.g., obsidian,
jade, gold, etc.). Some communities became influential through their central
location in trading raw materials, for example Çatal Hüyük
in Turkey (6500-5500 B.C.) controlled much of the trade in obsidian.
Centers of domestication
The process of domestication has
occurred independently a limited number of times in specific regions; these
are the primary centers of domestication. Other areas, secondary areas, received
the plants and animals from elsewhere. The primary centers are found in the
Near East, East Asia, sub-Saharan Africa, Central America, South America, and
North America (see handout).
Near East
The earliest evidence has come from the Near East, where wheat, barley, peas, lentils, pigs, sheep, goats, and cattle, were domesticated just after 8000 B.C., followed by other plants subsequently (see pages 206-207 in Price and Feinman).
During the Mesolithic there are many sites in the Near East which show substantial permanent settlements. Evidence of ground stone tools support the idea that wild grasses were widely exploited, along with evidence for storage (pottery), while hunting was still the principal source of meat and animal byproducts. However, during the Neolithic settlements expanded in size and number, with the associated increase in ground stone tools and storage. Here domesticated varieties of plants and animals make their appearance. Domesticated grasses like wheat and barley show morphologies that are more resistant to wind-born dispersal, and have larger seeds.
At sites in the Near East the zooarchaeological
pattern is for a decrease in the presence of wild game (gazelle, aurochs, etc.)
associated with an increase in domesticated sheep and goats (see pages 217-218
in Price and Feinman). At larger more sedentary communities there is a tendency
for exotic goods to become more numerous, as well as the construction of larger,
non-domestic structures, though the function of such buildings remains unclear
(e.g., Jericho).
East Asia
In East Asia millet and pigs were present by 6000 B.C. in North China, while rice (see page 209) was first cultivated in South China and Southeast Asia before 5000 B.C., along with some root crops.
In North China the impact of millet
cultivation shows with the presence of well organized continuously occupied
villages, with other activities including growing hemp for fibers, raising pigs
and dogs, supplemental food provided by hunting, fishing, and plant collecting.
Pottery was produced using kilns in an area away from residences.
Sub-Sahara Africa
In sub-Saharan Africa sorghum, African
rice, and pearl millet were domesticated for by 2000 B.C.
Central America
In Central America gourds, squash, avocados, chili peppers, beans, and corn were cultivated by 5000 B.C. The significance of animal domesticates is less than in other regions, though turkeys, dogs, and bees were domesticated. The archaeological evidence from early sites show the seasonal exploitation of wild squash and bean plants, which may have been tended or cultivated, perhaps taking the initial steps towards to domestication.
The domestication of corn (Zeas
mays) illustrates some of the trends for the process of plant domestication
(see pages 238-241 in Price and Feinman). The wild variety, teosinte, is a highland
grass that have readily dispersed small seeds due to the lack of a cob. These
have been recovered from Tehuacán, Mexico, at 2700-2500 B.C., in association
with seasonally mobile family units (called microbands) (see pages 242-245 in
Price and Feinman). Over time at Tehuacán, the percentage of corn increases
relative to other plants and animals, suggesting greater reliance on this cultigen.
This is marked by genetic changes (perhaps only a couple of changes) in the
species that resulted in larger ears, with bigger kernals and more seed rows
(as also described in the video Out of the Past: new worlds).
South America
In the highlands of South America
there is evidence that by 3000 B.C. that gourds, squash, tomatoes, beans, and
potatoes were domesticated. Animals were important domesticates, with the llama
used primarily for transport and ritual use, while the alpaca, a camelid like
the llama, provided wool and meat (as did the guinea pig). The domestication
of the llama would have required the selective breeding for more docile and
controllable animals, which was necessary for reliable pack animals. It has
been argued that the wild ancestors of some species (e.g., lima beans, manioc,
guava, coca) came from Amazonia, while potatoes and camelids are Andean natives.
As elsewhere, the domesticates were initially collected or hunted as wild species,
as part of a wider suite of exploited species.
North America
In eastern North America the marsh
elder, sunflower, and goosefoot were domesticated by 1000 B.C. (see pages 250-251
in Price and Feinman). Corn was introduced from Mexico into the Southwest by
1200 B.C., arriving in the Midwest by A.D. 1 to 200.
Explanations for the origins of agriculture
A range of hypotheses have been
suggested to account for the adoption of agriculture, with the emphasis being
on primary factors such as environmental change or population pressure see pages
200-202 in Price and Feinman). No single hypothesis will explain why this change
occurred in the places it did, as the conditions that preceded it varied, as
did the specific plants and animals people had available.
Oasis hypothesis:
This hypothesis argued that agriculture
occurred in areas where the nutritional resources for plants and animals were
confined to a oasis; that is, through shared confinement to local areas of dense
resources humans and animals developed a symbiotic association, prompting the
eventual herding of the animals, thereby providing continued access to those
resources.
Natural habitat hypothesis:
The argument here is that domestication
only took place in those areas where wild varieties naturally occurred, as seems
to have been the case for the Near East, where the Fertile Crescent was the
center of domestication for grass and animal species. However, no specific reason
for why the process of domestication took place where it or when it did.
Population pressure hypothesis:
Here the impetus for domestication
came from the need to provide enough food for a growing population. Arguing
from a processualist view, Binford considered that it was hterefore advantagous
for groups to more closely control their food resources through herding and
tending, which provided more food in more reliable quantities than could be
gained through wild sources.
Edge hypothesis:
Using the population pressure hypothesis,
Binford further felt that the population pressure would be greatest towards
the periphery of the environment, necessitating the ability to control the growth
and maturation of plants and animals.
Population pressure models were developed within a processual framework, representing
a systems analogy: changes in part of the natural or social environment prompt
changes or reaction in other parts (more people prompts changes in way of life
to enhance food production).
Social hypothesis:
Bender argued that the environment
and population pressures were less significant than social factors. In this
post-processual hypothesis Bender argued that domestication only became important
when it had a social value. When individuals saw the potential for food surpluses
and the ways in which to use it to gain prestige or power (though exchange or
trade for other status-defining resources), domestication became significant.
At present it is difficult to test these hypotheses, especially given that factors
like population pressure and social relations are difficult to identify archaeologically.