The Origin of Agriculture
Theories of Plant Domestication
By Steve Gagné (stevegagne.com)
In the distant past, a few Homo sapiens made a decision that altered the biological, psychological, and spiritual essence of humanity. That decision was to work in partnership with the land through the domestication of plants and animals. Researchers from numerous scientific disciplines have made great strides in attempting to explain the origin of agriculture. However, exactly when, how, and why this happened at all is still very much a scientific mystery.
The information gleaned from extensive research in this multi-disciplinary pursuit has offered a range of insights into how humans adapt to social and environmental pressures, develop patterns of health and disease, and structure sophisticated forms of culture and civilization. These ideas about agricultural origin are rooted in the cultural evolution theory, which today serves as the basis upon which academic beliefs and ideas are formed and supported by scientific research and modern technology.
Much of this research is based on fossil records, comprised of bones, seeds, and stone tools gathered from caves, hearths, and wherever ancient settlements can be uncovered. These records help us to formulate possible circumstances for addressing the following questions:
1. Where and when were plants first cultivated and identifiably domesticated?
2. What evidence is there to support current theories, and/or what alternative interpretations can we draw from the available evidence?
The Cultural Evolution Theory, Methodology and the Fertile Crescent
The earliest domestication of plants may have originated 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 5,000 and 10,000 years ago. Religious texts, legends, and archeological 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 would be used to substantiate the cultural evolution theory. This archeological evidence has helped create a consensus that has become the basis of today’s textbooks on ancient history.
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. Archeological and anthropological researchers commonly revise initial testing results for findings; this is a normal part of scientific procedure when 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 Americans 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. However, even with the latest technology, much of the seed remains found are so severely carbonized or decomposed as to 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 determine 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 10,000 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 involves about a half dozen cave sites.
In Mexico, samples of squash seeds and beans dating around 7,000 to 9,000 BP (“before present,” meaning before the radiocarbon baseline of 1950)1 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 seeds’ age 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 alternatively, that the charcoal sample had somehow been displaced upward from the deeper layer.2 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.
The Mexican sites, furthermore, 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 South 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 of between 1,000 and 2,000 years; current findings have pushed its origin back much further. The recent discovery of a handful of rice, found in the village of Sorori in central Korea and dating back 15,000 years, strongly suggests that an agricultural practice here coincided with or even preceded that of the Fertile Crescent—where agriculture is still held to have originated.
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 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.
Classification, Morphology, and Genetic Testing
When determining whether a plant should be classified as domestic, scientists look for large and fast-sprouting seeds, glume (grain hull) adherence, and strong rachises (the part of the grain that attaches the seed to the stalk). These traits are considered markers of domestication because, since they are naturally selected against in wild species, they could evolve only under cultivation.
Large seed size, for example, is usually considered a marker showing an adaptive response to selective pressures relating to domestication. The hunter-gatherer’s deliberate planting of slightly larger, pre-selected seeds from wild stands into seedbeds rather than into the plant’s natural wild habitat is believed to eventually cause morphological changes in the plants, resulting in larger, domestic-type seeds. By selecting wild mutant seeds with thinner glumes and stronger rachises, early hunter-gatherers were able to build up a seed supply of mutant seeds from wild stands over time. It is from this supply of stored mutant seeds that domestic cereals are said to have originated.
It is important to know that, even with the multiple scientific disciplines used to study agricultural origin, the sources of evidence vary considerably in reliability. The three important founder grains from the Fertile Crescent—emmer wheat, einkorn wheat, and barley—are the earliest examples known to be located near their wild relatives. There are several species growing today in the same area that are viewed as possibly being the original ancestors of these domestics.
However, after intensive study of morphologies and genetics, including analyses of plant proteins and interfertility testing, we are often still perplexed by a wild progenitor to which the domestic species appears morphologically identical but with which it has no genetic compatibility. To illustrate this “looks can be deceiving” aspect, Daniel Zohary states:
A special case of species diversity is provided by “sibling species,” that is, taxa so similar morphologically that it is very difficult—or even impossible—to distinguish between them by their appearance; yet, crossing experiments and cytogenetic tests reveal that they are already effectively separated from one another by reproductive isolation barriers such as cross-incompatibility, hybrid inviability, or hybrid sterility.4
A well-known example of sibling-species relations is that of wild and domestic emmer wheat. Triticum araraticumm, one species of wild wheat, is morphologically indistinguishable from domestic emmer wheat. However, all attempts to cross breed the two have failed, thus proving that the former was not in fact the progenitor of the latter. Furthermore, a true ancestor, morphologically different from emmer wheat yet with identical chromosomes, was found and successfully interbred, thus linking it credibly to emmer as a potential wild progenitor.
Wild progenitors used to be classified as separate species from domestics but are now ranked along with the domestics as a separate subspecies. For example, domestic emmer, Triticum turgidum, is the subspecies dicoccum. Its suggested wild ancestor, once called Triticum dicoccoides, is now classified as Triticum turgidum dicoccoides. What are the most obvious differences between them? The domestic grain somehow got larger, and the rachis got tougher and less brittle.
But are these variations, together with the fact that interbreeding was successfully accomplished under laboratory conditions, enough to identify Triticum dicoccoides as the wild ancestor of domestic Triticum turgidum? Or is there a danger here of leaping to simplistic conclusions?
We must remember that numerous factors, such as changes in climate or animal and human intervention, have influenced genetic variations and diversification among the wild progenitors over thousands of years. While it is generally believed that the wild progenitors of most cultivated plants have been satisfactorily identified, many researchers recognize the need for more data.
The simple identification of a morphological change does not, in itself, constitute adequate documentation of a plant species having been brought under domestication. Linkage must be provided between the observed morphological change and a set of causal behavior patterns. It is not enough simply to document phenotypic change. It is also necessary to explain why such change appears in response to a newly created environment of domestication.5
The example of wild and domestic emmer, Triticum turgidum, may fit most additional criteria for domestication, being that both the wild and domestic emmer could successfully interbreed and had identical chromosomes. Yet is it not possible that the putative wild ancestor of emmer could in fact have once been a cultivated escapee itself, one which then adapted to a wild environment over thousands of years?
Another example is the fragments of emmer wheat dated 9,500 BP from the southwestern tip of the Fertile Crescent at Jericho. Evidence as to whether the fragments are wild or domestic is still inconclusive. Other samples of emmer dated 9,700 BP and found just north of Jericho near Damascus, however, are domestic.6 Keeping in mind these specimens are thousands of years old and have been through extreme changes, is it not possible that, again, what are thought to be wild samples of emmer are simply genetically altered cultivars, that is, a once-cultivated subspecies that has since run wild?
In order to consider this possibility, we must reexamine the common assumptions about our earliest agriculture origins: could these “origins” in fact be examples of re-emergence from previous cycles of civilizations?
Without giving this consideration due weight, we are left with the mysterious appearance of numerous species of grasses, some of which share similarities to cultivated grain species both genetically and morphologically. One could argue that the dates of our examples fit the conventional time line (10,000 years for domestication), yet these are only a few examples of what has been found.
The recent and totally unexpected find of several grains of morphologically domestic emmer wheat at the Palestinian site of Nahal Oren also raises the possibility that grain was under cultivation as early as 14,000 BC.7
An archeological site called Ohalo II in Israel reveals 19,000 well-preserved grass grains. Among the specimens are pieces of wheat and barley dating 23,000 years ago8—about 7,000 years older than the Nahal Oren samples cited above! In light of findings such as these, it seems quite possible that many wild progenitors could be cultivars from a civilization or civilizations predating the orthodox theory for agricultural origin.
What are often called wild progenitors of domestic grasses may be suspect for other reasons. Several other sites in the Fertile Crescent have combined specimens of wild and domestic emmer, einkorn, and barley. The mix of wild progenitor and domestic is often interpreted as signs of early cultivation from wild to domestic. However, these may simply be examples of separate food stores for ruminants and humans. And while animal domestication does not happen until around 8,000 BC, according to orthodox timelines, it is still possible that a sufficient condition of pre-animal husbandry existed to account for wild grass harvests.
Cultivars and Wild-Growing Domestics
Einkorn wheat represents another perplexing example of early wild and domestic plant research.
The present-day northern portion of the Fertile Crescent yields broad bands of wild einkorn, yet research has designated the wild progenitor of domesticated einkorn as being restricted to a small region near the Karacadag mountains in southeast Turkey, far removed from the northern broad bands of wild einkorn. If the northern stands of wild einkorn are not the progenitors of domestic einkorn, then what are they? Could they be a once-domestic species that ran wild at some distant period of prehistory, eventually having adapted to their present environment?
It is believed that hunter-gatherers living in permanent settlements were harvesting a species of wild einkorn 11,000 year ago along the Euphrates River.9 If hunter-gatherers were already harvesting by that time, perhaps they had been harvesting it for thousands of years before that time. What species of wild einkorn was this? Was it the progenitor of domestic einkorn, the species found in the Karacadag mountain region? Or was it another species, like the one representing the broad bands of the northern regions, a species that never became domesticated?
For that matter, what about the modern wild einkorn found in the area comprised of Israel, Lebanon, southwest Syria and Jordan? This Palestinian variety has large seeds, often larger than those of domestic wheat.10 Could these, too, be feral crops that were once cultivated in antiquity and have now adapted to the regions? Large seed size is considered a marker of domestication—yet this wild species has seeds larger than most domestic species.
As long as we are focused on the Fertile Crescent, let us consider the origin and introduction of barley, the third founder crop of this region.
Two types of domestic barley have been recovered here from early settlements. It has been suggested that hunter-gatherers harvested wild barley before domesticating two-rowed barley, followed shortly afterwards by six-rowed barley. Between these two types, two-rowed barley shows more of the wild barley characteristics; both two- and six-rowed domestics have been found together in early settlements.
Wild barley, like wild einkorn and emmer, develops brittle rachises for dispersal when fully ripened. These rachises are segmented so individual spikelets and grains can be shed from top to bottom when ripe. Only about five to ten percent of the rachises are semi-tough in wild barley, and this small percentage represents the average amount of seed that is held to the stalk at the time of maturity.
According to theory, early hunter-gatherers selectively chose seeds from these specific stalks at an early stage before ripening; they did so because even if the five to ten percent of rachises held their seeds, at maturity they would immediately fall to the ground when pulled by the hands of humans. The hunter-gatherers (so goes the hypothesis) would have saved these partially ripened seeds for planting stock.
In order to be motivated to do this, these hunter-gatherers would have had to believe that these wild grass seeds, after being planted in homemade seedbeds, would produce larger, more stable seeds and larger yields after a few generations. Are we to assume that they knew what the outcome would be before they tried it? And are we to further believe that these wild grasses could genetically morph into domesticates through simple cultivation and planting techniques, when it has still not been demonstrated today, nor is there any evidence that such a demonstration is possible, that a wild, mutated seed can be transformed into a domesticate through cultivation in a foreign seedbed?
As with emmer and einkorn wheat, it is not uncommon to find wild and domesticated barley fragments together in archeological sites. In areas of the Fertile Crescent, fully cultivated emmer wheat and two-rowed barley have been recovered from ancient sites, accompanied by wild-weed einkorn, ryegrass, and other weeds considered pre-adapted to cultivation. It is still highly questionable whether or not the selective pressures imposed on wild grasses, as suggested by the cultural evolution model, caused the morphological changes that resulted in domesticated varieties of cereals.
Early hunter-gatherers were just as highly attuned to their food sources as modern day hunter-gatherers. With hundreds of thousands of years’ experience in finding food, knowing which plants to eat, observing animals in their natural habitats, and incorporating some of these habitats into daily life, it is difficult to believe that these people, who hunted and ate ruminants, were ignorant about the wild grasses eaten by these animals. After all, countless generations of hunter-gatherers used wild grasses for bedding, weaving baskets, and fuel. Could these tough, brittle, wild grains really have been food for these early people, as suggested by some leading specialists?
While there is plenty of evidence for wild grain harvest, there is actually little evidence supporting human consumption. Evidence for the latter is restricted to a few Paleo feces found in caves. The location and lack of evidence would suggest that a famine or climatic disturbance might have been in effect, causing the humans to hole up in the caves until it was safe to venture outside. If this were the case, the usual foods may have become scarce, causing those people to eat whatever they could find. (We must also consider the possibility that Paleolithic peoples were able to process wild grasses, rendering them digestible and fit for human consumption, without the pottery to soak the grains or cook them, but this possibility is quite slim.)
Proteins can be useful genetic markers for distinguishing wild ancestors from domestics. Shared genetic characteristics, if found, can reveal the wild progenitor of the domestic. However, this methodology is difficult to apply if the wild progenitor no longer exists, as is often the case, leaving us with hypothetical ancestors that must have been the progenitors of existing wild species.
Cross-pollination, genetic exchange, and environmental changes have blurred the lines between wild and domestic varieties over thousands of years. Along the way, opportunistic weeds of many varieties have joined the mix and contributed to new gene pools. In essence, it becomes increasingly difficult to determine whether the domestics came from weeds or the weeds came from the domestics.
A good case in point is teosinte, a diverse group of wild grasses native to Mexico, Guatemala, and Honduras.
Teosinte is suspected to contain the progenitor of domestic maize because the two are genetically compatible and successfully crossbreed through repeated hybridization in fields. They differ, however, in the morphology of the female ear. The few small seeds of teosinte husks look nothing like the large, fully seeded ears of maize. Teosinte has numerous branching stalks, each culminating in a few small, shattering seed spikes. Corn, (maize) on the other hand, is a single stalk containing an ear of tightly arranged, rowed seeds that cannot disperse naturally.
Because of its unique makeup, some experts believe teosinte to be a descendant of domestic maize; most agronomy books and relevant literature see it the other way around, and present teosinte as the wild ancestor of maize. Yet regardless of which direction one subscribes to, teosinte-to-maize or maize-to-teosinte, how such an extraordinary transformation could have taken place in the remote past at all is an inexplicable mystery.
Many varieties and sizes of domesticated corn have been found in deep levels of caves throughout Mexico, revealing the extensive knowledge of plant genetics and breeding techniques among early inhabitants of Mexico and Peru. A comparison of proteins between teosinte and domestic maize reveals some similarities, and no species of wild maize has yet been found. Some teosinte types have been categorized as subspecies, yet there are no morphological indications of their transformation into domestic maize.
With all our current technology, it seems reasonable that we should be able to create a domestic species from a wild one in a controlled environment, simulating an early hunter-gathers’ planting methods—if that is indeed what happened. What would it take? In addition, if this would prove the prevailing theory of wild mutant seed transformation, why haven’t we yet done it?
Identification of chromosomal affinities between wild and domestic crops is another method for finding wild progenitors. If cultivated crops show full homology and interfertility with a wild species from the same genus, then that wild species could be recognized as the ancestor of the crop. This may be misleading, though, because chromosomal affinity does not necessarily determine ancestry. This is especially true when there are wide variations in morphology, as is typical with many grain progenitors and their domesticated offspring.
An obvious advantage of domestication traits is that they evolved only under cultivation and are strongly selected against and absent in the wild.11
If this is true, it should be easy to reverse the process and produce wild, “shattering” crops from domestics once the specific gene sequence is found. (“Shattering” crops are those wild forms whose seeds drop to the ground upon ripening, rather than adhering to their stalks, as do the seeds of domestics.)
…crosses between wild progenitors and the cultivars have shown that this shift is brought about by a recessive mutation in one major gene or (more rarely) by a joint effort of two such genes. In all these crops, breeders have also performed many intra-crop crosses (between cultivars). Except for barley, none of these within-crop crosses has been reported to produce wild-type brittle or dehiscent…12
It would appear that our ancestors were able to “tweak” that single gene from wild grasses so that it could not be reversed. Only domestic barley, with its two independent recessive genes, has successfully produced wild type, brittle grains and these are still different from the “wild species.”
Aside from wild chenopod pseudo-cereals that shed their seeds in a couple of days at maturity and can be husked by simple rubbing and winnowing, the idea of pre-agricultural peoples regularly consuming wild grasses (progenitors of einkorn, emmer, barley, rye and spelt) as promoted by some researchers may simply be an attempt to promote and maintain the cultural evolution theory as applied to plant domestication. The premise that Paleolithic humans ate wild grasses that may have led to the eventual domestication of the wild species also supports this gradual-step theory. This is not unlike the theory that seed plant cultivation followed other vegetable plants. Evidence for hunter-gatherers cultivating propagated vegetables before seeds is lacking, but the theory of a gradual-step process comfortably fits the current paradigm.
Could these grass species of einkorn, barley, and emmer, so often suggested as the wild progenitors of their modern day domesticates, be something other than wild?
Based on the hypothesis that over thousands of years a plant could experience numerous morphological changes, is it not possible for a once-domesticated plant to revert to some semblance of a wild version? We have already mentioned how it has been suggested that wild grass species, once cultivated, could morphologically transform within 300 years when transplanted into seedbeds. An example of this morphological change could appear as brittle rachises becoming “semi-tough” enough to be identified as cultivated.
While this may be possible, it raises another question: could other important markers (thinner glumes, larger seeds, greater adaptation to climate and soils, resistance to diseases and pests, etc.) that resulted from selection pressures and were found in domestic species also have morphed along with the rachises, or did some of these traits occur earlier and others later?
Some of these developments are major adjustments to a wild grass species involving genetic manipulation at some level in the process, and there is no indication these markers, not to mention increased nutrition and faster sprouting time, could have occurred consecutively or simultaneously over a few hundred years by being planted in seedbeds, even if the seeds were carefully selected, wild, mutant seeds. Granted, some hunter-gatherers from the epi-Paleolithic period knew a great deal about the growing cycles of plants (and even about seed planting and cultivation to some degree), but the genetic manipulation of a wild grass species into a productive, nutritious offspring is something quite extraordinary.
The question thus remains: who were these people and how did they know how to manipulate plants at the genetic level? Evidence at many archeological sites indicates that the knowledge for plant domestication was already there and was not an evolutionary process.
The idea that many of these “wild” species of cereals are actually cultivars is a realistic consideration. Edgar Anderson addresses this important issue in his book Plants, Life and Man. He suggests that we consider previous cycles of cultivation when examining what we think are “wild relatives” of our basic food crops.
This is indeed a consideration for researchers, as it is now well known that some species were in fact cultivated before the time they were once thought to have originated. Corrections in origination dates, along with genetic mixing of wild and domestic crops, environmental pressures, and time can realistically contribute to de-evolution of a domestic species.
An example Anderson gives, of how one might encounter in a jungle a smaller version of a cultivated fruit, giving the first impression that it is a wild relative of the domestic version, is an all-too-common occurrence. While it is possible that what you are witnessing is a wild food, it has been repeatedly shown that many of these wild-appearing foods are remnants of refuse heaps, a seed spit out of a hunter’s mouth after finishing his lunch from home where he cultivated the fruit, or a garden escapee. I have personally encountered wild-growing samples of cacao, coffee, papaya, avocado and other familiar varieties while in the remote jungles, far from any agricultural base, of South and Central America.
Anderson also points out the great variations among wild-growing domestic avocados in Central America. Such variations appear to an even greater extent among avocados presently growing under managed cultivation. He brings to attention the fact that apples appear in pastures, forests and fields throughout the country, yet none were here in America when the first European colonists arrived. Apples are likely from Asia, where various species are native. We do not know how much of a connection the wild-growing apples have with previous cycles of cultivation, but they are, without question, examples of cultivated apples that have run wild. The same is likely true for many “wild” relatives of cereal grains. At my home in Vermont, we have three apple trees and two pear trees on our land. We were the first on record to build on this particular spot yet, although we did not plant the trees, they are not wild fruit trees.
Wild weeds are highly successful plants that can easily overcome a disturbed habitat, as evidenced in most gardens by weed races commonly found among domestic annuals and perennials. Early hunter-gatherers, like their modern counterparts, are known for having collected and stored a variety of wild seeds. Most of these seeds are known for specific uses, such as food or medicine. But what evidence is there that pre-agricultural peoples actually used wild grasses for their own consumption?
Jack Harlan, an authority on agricultural origins, was able to prove that a small group of people, within a period of just three weeks, could harvest by hand enough wild grain to sustain themselves for one year. To some, this classic study suggests that our ancestors did the same. However, it does not prove that they did nor answer why they did it if they did. Were harvests for pre-domestic ruminant consumption, or for some other highly useful purpose?
Recently, a team of international scientists found fields of wild einkorn wheat in the Near East that provides the closest genetic match to domestic einkorn. By obtaining DNA samples of 68 separate lines of cultivated einkorn, all samples were found to be closely related. DNA profiles were also taken from 261 separate populations of wild einkorn in the same area. Of the 261 wild samples, 19 from the volcanic region of the Karacadag Mountains in Turkey were distinct from the other wild einkorn lines. Further analysis showed that 11 of the 19 samples had a close phylogenetic similarity to the cultivated einkorn. As a result, these 11 wild samples could be identified as modern descendants of the wild progenitor for einkorn wheat.13
Note that these wild samples were identified not as wild progenitors but as descendants of a wild progenitor, based on their similarity to the domestics. But how can they credibly be seen as descendants of a wild progenitor if we do not know where or what the wild progenitor is? Phrases such as “similar to,” “related to,” “descendants of,” and so on imply a link to some long-lost original strain of wild grass that, through a series of mutations, became the domestic grain we know today. Yet, in many cases, there is still no actual progenitor.
Evidence does strongly suggest an area for the earliest domestication of einkorn wheat, but, like so many other domestic plants, the wild progenitor remains elusive. What we have are suspected descendants of these elusive wild progenitors, much like the situation in the study of human origin with its search for the elusive “missing link.”
The Process of Cultivation and Other Theories
The presence of grinding stones, sickle blades, and storage structures in many early hunter-gatherer sites indicates a long reliance on wild seeded plants, particularly wild grasses. Refinement of harvesting and cultivation techniques by selectively choosing plumper seeds eventually transformed fields of grain into crops with thinner husks, stronger and less brittle rachises, stalks with increased seed clusters, larger and more dependable yields after harvesting and threshing, increased nutritional value, and spare seed for storage. These newly cultivated crops could have eventually replaced their wild counterparts in importance. After much trial and error, these once-wild grasses, first through careful selection of suitable wild seeds and later through repetitive cycles of sowing, reaping and harvesting, became domestic crops fully dependent on human intervention.
Some archeobotanists believe morphological changes, which include changes in size, shape and form, could have taken place anywhere from 100 to 300 years after the first time a seed was planted in a seedbed by early hunter-gatherers. Others believe it may have taken longer, up to 1,000 years. This is an interesting hypothesis that appears to be based on sound evidence, albeit interpreted though the theory of cultural evolution. Nevertheless, it is a hypothesis—not a fact. The evidence is therefore open to interpretation from alternative perspectives as well.
In Origins and Seed, Gordon Hillman discusses cultivation as a precursor to domestication and suggests that cultivation in the Jordan Valley could have started as early as 12,000 BC. He further states, “However, detecting the start of cultivation will, as ever, be problematic.” The reasons for this, says Hillman, are that “cultivation prior to domestication can be recognized only from indirect evidence, not from the remains of crops themselves” and “domestication itself is often difficult to detect.” Further influences in the process would include unripe harvesting and genetic infiltration of wild genes from neighboring populations of wild grasses.
Indeed, even with the most rapid domestication, it is inevitable that “modifier genes” would have ensured that the crops continued to contain an admixture of wild forms for many centuries … This effect, combined with the inherent problems of distinguishing wild and domestic cereals from charred remains [archeological records], ensures that detection of domestication in the archaeological record will continue to be extremely difficult.14
So, why cultivate in the first place? Why spend centuries planting something that will not produce the desired result for generations? Furthermore, when the plant finally does reach its full potential its product becomes a causal factor, according to many historians, in both the creation and downfall of civilization. Authority Jack Harlan nicely sums up the scientific position on the question of cultivation:
What does planting and reaping, planting and reaping, that is farming, do to the genetic architecture of annual seed crops? Most of our answers to this and similar questions have been intuitive or simple guesswork.15
Again, while there is no doubt that wild grasses played an important role in the lives of hunter-gatherers, it may not have been for food.
What about those 261 “wild” samples from the Fertile Crescent, only 19 of which have genetic similarities to domestics? Could these be additional examples of cultivars that have morphologically reverted to their present status after running wild some thousands of years ago?
Research has shown that some early hunter-gatherers from the Fertile Crescent practiced what is called vertical transhumance, wherein groups of people would seasonally move their campsites from low elevations to higher elevations in the spring to harvest ripening wild grasses and to hunt wild goats and sheep that followed these ripening grasses. If we remove the cultural evolution model as an interpretation for this scenario, we are left with typical pastoralists herding their flocks to ripening grasses. Admittedly, this would be at a time well before they are believed to have had domestic animals—but the truth of the matter is that, as with our inconclusive results concerning plant domestication, we really do not know when animals were first domesticated.
The majority of researchers still either hold to the Fertile Crescent theory or believe that plant domestication began independently in several parts of the world within the last 5,000 to 10,000 years. Both perspectives depend on the cultural evolution theory for their basis. Either orientation posits a long period of experimenting by hunter-gathers with wild grasses and roots predisposed to domestication before agriculture appeared on a large scale.
But is it possible, at least in some of the major areas where agriculture began, that plant domestication did not happen through this evolutionary process of human experimentation? Although it specifically addresses contact between the hunter-gatherers and early farmers of central and northern Europe, the editors of Last Hunters—First Farmers offer another suggestion that could easily be applied to any number of other locations where agriculture began:
The origin of agriculture involves only a very few places in a few brief moments of time. The spread of agriculture is the primary means through which farming has become the basis of human subsistence. It would seem essential to keep both colonization and adoption, and the kinds of evidence and questions that they involve, in mind in any discussion of the transition to agriculture.16 [Emphasis added.]
Agricultural origins cannot at present be conclusively proven to have begun close to 10,000 years ago when additional evidence for agriculture extends further back in prehistory. What can be unequivocally stated is that agriculture had already emerged several times in numerous parts of the world in the last 12,000 to 20,000 years, and possibly as early as 50,000 years ago, with the last 6,000 years producing the most evidence for this cultural phenomenon.
New findings challenge the hypothesis that humans first began as hunter-gatherers and later evolved to agriculturists some 10,000 years ago—a hypothesis that at present has no solid basis in proof, yet is readily believed by many.
Genetic manipulation of plants, particularly cereal grains, occurred at some point in prehistory by people who already had the knowledge to do so. These same people created a vital and lasting human food source, no doubt for very specific reasons.
In each of the major areas of the world where plants and animals were domesticated, we find legends, both written and oral, describing the origin of agriculture as a gift of the gods, culture-bearers who taught indigenous peoples agriculture and the sciences of civilization. (I have written about this elsewhere, in an article soon to be posted on this site.) Could this possibly be coincidence, the accident of mere imagination?
Our ancestors left us more than bones, seeds, stone tools, priestly cults and ritualistic incantations to exotic gods—they left us examples of extraordinary feats of engineering, architecture and sustainable methods of agriculture. They left us legends, myths, epics, and sagas. Isn’t it about time we hear them out?
1. A Dictionary of Quaternary Acronyms and Abbreviations, www.scirpus.ca/cgi-bin/dictqaa.cgi? Option=b; May 5, 2004.
2. Smith, Bruce D., The Emergence of Agriculture; Scientific American Library; NY, New York; 1998, p. 165.
3. Dr. David Whitehouse, “World’s ‘Oldest’ Rice Found,” British Broadcasting Corporation News (BBC); October 21, 2003.
4. Harris, David R. (editor), The Origins and Spread of Agriculture and Pastoralism in Eurasia; UCL Press, Ltd.; London, England; 1999 (paperback edition), p. 151.
5. Price, T. Douglas and Gebauer, Anne Birgitte (editors), Last Hunters—First Farmers; School of American Research, Santa Fe, NM; 1995, p. 198.
6. Smith, Bruce, cf. ante, p. 60.
7. Settegast, Mary, Plato Prehistorian; Lindisfarne Press; Hudson, NY; 1990 (paperback edition), p. 3.
8. www.scientific american.com; June 22, 2004.
9. Smith, Bruce, cf. ante.
10. Harlan, Jack, The Living Fields; The Press Syndicate (University of Cambridge), Cambridge, U.K.; 1995 (paperback edition), p. 95.
11. Harris, David R., cf. ante, p. 154.
12. Ibid., page 154.
13. Smith, Bruce, cf. ante, p. 47.
14. Harris, David R., cf. ante, p. 194.
15. Harlan, Jack, cf. ante, p. 34.
16. Price and Gebauer, cf. ante, p. 126