The earliest domestication of plants may have been in the Near East’s “Fertile Crescent,” an area that stretches from the eastern shore of the Mediterranean Sea and curves around like a quarter moon to the Persian Gulf.
For nearly two centuries, explorers and scientists from different parts of the world have traversed this area in search of the origins of civilization and agriculture. Einkorn and emmer wheat, barley, and lentils, goats and sheep all purportedly originated here between five thousand and ten thousand years ago. Religious texts, legends, and archaeological discoveries document the antiquities of Sumer, Ur, Babylon, and other thriving cultural centers. This part of the Near East housed a literal treasure trove of artifacts, bones, and seeds that were used to substantiate the cultural evolution theory.
This archaeological evidence has helped to form a consensus that has become the basis of today’s textbooks on ancient history, prehistory, and culture.
The most thoroughly researched area of the world for the advent of civilization, the Fertile Crescent, is held today as the model to which all other such research sites throughout the world are compared. The Fertile Crescent, goes the theory, is where it all began—agriculture, civilization, all of it. Indeed, this “cradle of civilization” idea is so entrenched a part of historical orthodoxy that its axiomatic status has served to discredit those pieces of evidence that seem to challenge it.
This sort of fitting fact to theory is not new in scientific methodology. Archaeological and anthropological researchers commonly revise initial testing results for findings; this is a normal part of scientific procedure whenever deemed necessary.
For example, South and Central America are still termed “New World” countries, the underlying assumption being that their development must postdate that in the Near East. However, increasing amounts of controversial data are being found both in the Americas and in parts of Asia. Such evidence is tested with a variety of technologies, including accelerator mass spectrometry (AMS), which is in essence an upgraded form of radiocarbon dating.
AMS can accurately date samples as small as a single grain while detecting and reducing errors from fossil displacement. This can be especially useful when a sample (say, of bone or seed) has a different date than that of the strata in which it is found. However, even with the latest technology, much of the plant remains found are so severely carbonized or decomposed that they make it extremely difficult to determine whether a sample is wild or domestic.
Carbonized seed remains are a common source of agricultural evidence. The process of carbonization
occurs when organic compounds are subjected to high temperatures and converted into charcoal. While this process does preserve remains for reliable analysis as to composition, it also causes morphological changes that can make it difficult to distinguish wild varieties from their domestic counterparts. Among grass seeds, there is also the problem of trying to determine the relationship, if any, between the wild grasses (emmer, einkorn, and barley) of ten thousand years ago to those of the present. Wild stands still grow throughout the Fertile Crescent and beyond.
The Independent Location Theory
While ancient plant remains have been extensively studied in the Near East, such is not the case in the “New World.” Plant domestication research in Mexico and South America currently involves about a half dozen cave sites.
In Mexico, samples of squash seeds and beans dating around 7000 to 9000 BP (“before present,” meaning before the radiocarbon baseline of 1950¹) have been found in the deepest strata in some of these caves. Domestic squash seeds found in a cave at Oaxaca, for example, were dated at 9790 BP—the oldest date of any domestic plant species found in the New World.
Testing was based on dating a charcoal sample found next to the seeds; because of the extreme antiquity of the date, the age of the seeds was immediately cast into question. It was suggested that the seed samples had somehow been displaced downward from the upper level of the cave, or that the charcoal sample had somehow been displaced upward from the deeper layer². Both explanations are possible—yet one cannot help but wonder why experts feel compelled to resort to such elaborate reasoning when the discoveries occur in a location so far removed from the established Near East cradle.
Furthermore, the Mexican sites are not alone in this. The people of other ancient civilizations from the Peruvian highlands, China’s Yangtze River valley, and parts of Egypt, India, and Papua New Guinea all may also have domesticated plants dating back as far as those of the Fertile Crescent. However, the excavations for evidence of agriculture at these locations are still in their infancy and cannot yet be compared to the extensive findings in the Fertile Crescent.
Another part of the world with a long history of agriculture is Southern Asia, where a wide variety of annual and perennial forms of “wild” or “free-living” rice survives today without human intervention. Not too many years ago, domestic rice was thought to have a history going back between one thousand to two thousand years; current findings have pushed its origin back much further. The recent discovery in the central Korean village of Sorori of a handful of rice dating back fifteen thousand years strongly suggests that an agricultural practice here coincided with or even preceded that of the Fertile Crescent—which is still nevertheless viewed by many researchers as the site of agriculture’s origin.
"The age [of the Sororian rice] challenges the accepted view that rice cultivation originated in China about 12,000 years ago... The region in central Korea where the grains were found is one of the most important sites for understanding the development of Stone Age man in Asia."³
After thousands of years of cultivation, it is difficult to establish the identity of the original wild progenitor of domestic rice. Researchers struggle with whether present “free-living” rice is truly wild, a cultivated escapee, or something in between: cross-pollination, genetic exchange, expanding landscapes, and shrinking natural habitats have distorted genetic qualities between wild and domestic species. “Weedy” forms of rice have also evolved over time, escaping into unmanaged natural habitats, flourishing at the edges of agricultural landscapes and exchanging genetic material with both wild and cultivated varieties.
Even as they wrestle with the problem of potential multiple domestication sites, researchers are also faced with this paradox of the origins of agriculture: Why did hunter-gathers begin domestication of plants in areas with ample resources of wild foods? Thus, experts today still cannot state conclusively where plants were first domesticated and agriculture began—and the very hypothesis that it began because of hunter-gatherers’ need for a new food source is under challenge as well.
Notes
2. Bruce D. Smith, The Emergence of Agriculture (New York: W. H. Freeman and Co., 1999), 165.
3. David Whitehouse, “World’s ‘Oldest’ Rice Found,” British Broadcasting Corporation News (BBC), October 21, 2003.
By Steve Gagné in "Food Energetics", Healing Arts Press, USA, 2008, excerpts chapter 37. Adapted and illustrated to be posted by Leopoldo Costa.
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