When one considers the evolution of civilization, we tend to focus our attention on our major accomplishments such as the development of writing, the building of monumental structures and the wars, battles and conflicts that shaped a nation. The meteoric rise of nation-states around 6,000 years ago still confounds historians. Why did it occur? In their search, they tend to overlook the mundane things that set the stage for these rapid changes to transpire. Yet, even in the commonplace, how some of the simplest things came into being is still a mystery.
Agriculture is a defining achievement in the development of civilization. Other accomplishments, such as laws, cities and even the written language were built upon the structure that agriculture provided. For thousands of years our ancestors survived by living a hunter/gatherer lifestyle. They were omnivores and lived on a diet that included fresh meats, fish, fruits, vegetables, seed and nuts. Then about 10,000 years ago, people from remote parts of the world (Mesopotamia, China and Mexico), abandoned their foraging way of life and began cultivating crops. In cultures where agriculture became their base, civilization soon appeared. This was a remarkable change for nomadic groups that survived through hunting and gathering for hundreds of thousands of years.
Experts have suggested that living a hunter/gatherer lifestyle was difficult and time-consuming. They imply that the development of agriculture allowed people to live in large, sedentary communities where they would have more leisure time. This paradigm shift supported job specialization, which, in turn, facilitated the development of the arts, writing and other technical advances.
Robert Guisepi, of the International History Project, states, “There is nothing natural or inevitable about the development of agriculture. Because cultivation of plants requires more labor than hunting and gathering, we can assume that Stone Age humans gave up their former ways of life reluctantly and slowly.” Agriculture is touted as an upward evolutionary step. Our focus as humans shifted from the simplicity, yet uncertainty, of hunting and gathering to a greater dependence on the labor-intensive cultivation of crops.
These early farmers worked all day instead of a few hours a day, as did their hunter/gatherer predecessors. The freedom they had once experienced was lost to work schedules that had to be met. This change ultimately led to a lower quality of life and a decline in overall human health. According to Dentist and Naturopath Dr. Alison Adams, “The archeological fossil record indicates that the introduction of the agrarian diet coincided with a massive decline in the health and vitality of the population. Prior to this time there was no evidence of degenerative diseases or tooth decay, but with agriculture both men and women lost considerable height which has only now been recovered after 10,000 years. There is also evidence that there was a massive increase in infant mortality at this time.”
The dilemma we face, as we look at the development of agriculture, is why was a more difficult set of behaviors reinforced and ultimately adapted? What compelled man to forego his independence for the impersonal and complex political life of the city? Was the advent of agriculture and its associated stratified society a natural part of man’s natural social evolution or was there some intangible factor that motivated this drastic change? Theories do exist, yet few satisfactory answers have emerged to answer this paradox.
Yet, within a few thousand years, the old hunter-gatherer style of social organization started to decline. It was replaced by a society that was hierarchical. As villages and then cities grew, government's, socioeconomic classes, and specializations emerged. Wars between rival groups began with the rise of property ownership. This behavior was unseen in the hunter/gatherer society who had no concept of land as something belonging to one person or group.
Why did humankind began cultivating crops in the first place?
Legend tells us that the gods provided humanity with the knowledge of agriculture. Chinese mythology, for example, informs us that the gods taught man a number of things including the domestication of plants. The people were also provided with various agricultural tools and the knowledge of irrigation. A similar story comes to us from the apocryphal Christian Book of Enoch, where we learn that the “sons of god” acquainted humanity with knowledge of plants and the cutting of roots. Myths of the Hopi Indians tell us that the Kachinas came to the Hopi villages and taught them various forms of agriculture, while in Mesoamerica, the god Quetzalcoatl taught humanity how to cultivate corn seeds. Did the gods of antiquity play a role in adoption of agriculture? Did they also play a pivotal part in the evolution of grains from their humble origins to the grains we know today?
Grain consumption, including wheat, rice, corn and barley makes up a large portion of the human diet. Its development, though often discussed in a cursory way, presents us with a number of odd twists of fate that justify a deeper look into its development.
It was about 35 – 40,000 years ago, with the advent of the “creative explosion” that humanity began to exploit plant roots high in carbohydrates, such as cattails and ferns, to make bread. The roots, in order to be consumed, had to be peeled, dried and finally ground into flour. The processed flour would be mixed with water, fashioned into a flatbread or cake, and cooked. All of these steps were required before the starchy plant matter could be eaten.
It is unclear when we started eating the seeds of grasses. Grass seeds, like the roots of cattails and ferns, require considerable processing before they can be consumed. First, the small seeds have to be harvested. The grains have to be separated from the uneatable outer portions of the plant, the chaff. Then it has to be cooked, ground or both before it can be utilized. This is a time consuming, multi-step process.
Even with all of the labor required in producing a loaf of pita-like bread, it was nature that gave us the biggest hand in the progression of wheat from its seed-like origin to what we consume today. The development of modern wheat has not relied solely on a series of genetic mutations. The major factor in its transformation was hybridization.
Traditionally, if two species are genetically similar, crossbreeding can occur. It is common in nature to have species mix. Breeding across different species, however, produces sterile offspring. Hybrids can be found in the animal kingdom. Mules, donkeys, cattle, livers, and yakalo are all examples of infertile hybrid animals. The same genetic rules apply to the plant kingdom. A red delicious apple can be crossed with a McIntosh, for instance, but it cannot mix with something like a cherry or a grape. But that is not what happened 30,000 years ago.
According to scientists, at about the same time we started baking flatbreads, a very strange genetic event occurred in the plant kingdom. Wild einkorn wheat (Triticum monococcum) crossbred with a species of goat grass (Aegilops speltoides) to produce what is known as Emmer Wheat. Genetically, einkorn wheat and goat grass each have 14 chromosomes. If we call the 14 chromosome genetic structure of einkorn wheat AA and the 14-chromosome structure of goatgrass BB, when they combine, the resultant hybrid crop should have a genetic structure of AB with a corresponding 14 chromosomes. This cross-bred hybrid plant, with half of its genetic material coming from each parent, would be, like other hybrid plants, sterile in nature. Nevertheless, this is not what happened in the case of emmer wheat. Its genetic structure instead of having the expected AB chromosomal mix contains the full genetic structure from both parents (AABB). This combination of cellular materials, with its full complement of genes, restored fertility to the resultant plant. Surprisingly, only one twenty-eight-chromosome species of wheat can be found in nature: wild emmer. Grains of wild emmer, discovered in at the ancient site of Ohalo II, date back to 17,000BC.
The domestication of wheat, both einkorn and emmer, around 10,000 years ago, according to researchers, allowed our ancestors to move from a hunter/gatherer lifestyle to a more pastoral and agrarian one. Whether it was part of an ongoing genetic miracle or was selectively bread into the plants, as is claimed, a number of critical modifications occurred once wheat was domesticated. One of the hallmarks of domestication is a non-shatter rachis. The rachis is what holds the ripened seeds on the stem. When they shatter, the seeds disperse, propelling them mechanically into the ground. This supports self-cultivation. A non-shatter rachis, on the other hand, prevents seed dispersal. This also allows for easier grain collection and an increased harvest. The appearance of a non-shattering rachis in early cereal domestication is consistently found in the evolution of grains such as rice, wheat, corn and barley.
During this early period of wheat domestication a second miraculous genetic anomaly occurred. Modern bread wheat is a hexaploid organism, meaning it has six full sets of chromosomes. Sometime around 10,000 years ago, the newly develop emmer wheat (AABB) crossed with an unrelated form of wild goat grass, (Aegilops tauschii (DD)), to produce a new grain whose genetic structure contained 42 chromosomes (AABBDD). This newly emerging species is what is known as bread wheat today. Interestingly, no wild forms ofhexaploid wheat exist on the earth.
Taken as a whole, the evolution and development of wheat, including emmer and bread wheat seem to be anything but natural. Its evolution seems more like a work of fiction or something that has come to us directly from a genetically modified organism (GMO’s) lab. Scientists, at the labs of the International Maize and Wheat Improvement Center (CIMMYT), have been attempting to reproduce what is believed to have been a natural occurrence. “We’ve been reenacting in the lab what took place in nature nine-thousand years ago,” stated researcher Richard Trethowan. Trethowan has been crossing wild goat grass with a modern version of emmer wheat to produce a new form of bread wheat. This process performed in the lab is anything but natural. Chemicals are used to induce hybridization and the chromosome doubling in these two distinct species.
The mystery does not end there. Wheat is a finicky grain to grow. The soil and climatic requirements are more exacting when compared to other cereals. Why did our ancestors spend so much time developing a grain that is cumbersome to grow and whose yields tend to be low? Additionally, for the successful dissemination and propagation of these hybrids, historians expect us to believe that one single solitary isolated genetically anomalous hybrid plant started a revolution. Could the seeds of a lone plant produce enough fertile offspring to become the dominant species in a given area? In the case of modern bread wheat, it is argued that our forefathers detected the subtle improvement to the grain (bread wheat has larger seeds due to the additional chromosomal material), saved these seeds and use them to cultivate a new generation of crops. While it is possible, is it plausible?
Since the emergence of bread wheat about 10,000 years ago, the unlikely, yet successful, crossing of two distinct species of wheat has never happened again. Scientists continue to claim that nature was able to produce a series of fortunate genetic anomalies that ultimately transformed humanity, yet are still unable to explain how they occurred.
It is not only in the development of modern wheat that we find unexplainable events occurring in the plant kingdom that ultimately benefitted humanity. The origin of maize (corn) has intrigued historians and geneticists alike. The identity of maize’s wild ancestor has long been a mystery. Scientists were at a loss to explain where it came from. Maize does not grow naturally on the planet. The appearance of a plant, with soft starchy kernels arraigned in long rows on a cob, appears abruptly in the archaeological record of the Americas. Evidence suggests that corn was part of their local diet about 9,000 years ago. Milling tools, with maize residue on them, have been discovered in the Xihuatoxtla shelter of Balsas region of Southern Mexico that date back 8,700 years.
Researchers, like Harvard professor Paul Mangelsdorf, believe that early farmers domesticated a wild form of maize which is now extinct or has yet to be discovered. In the last few years, however, geneticists think they have uncovered its source. Evolution is thought to occur gradually through minor changes over extended periods. This is not what geneticists found when they sought the origin of corn. Recent research seems to indicate that the development of corn was a feat of genetic engineering. They believe that corn was intentionally developed from the wild grassy plant called teosinte.
The confusion experienced in the past occurred because the seeds of teosinte do not resemble maize in its general appearance. Where we would expect to find an ear of corn, teosinte plants contain clusters of slender seedpods. Each seedpod contains 3 to 8 very tightly enclosed seeds, which are covered in a hard, woody protective casing, called a glume. The glume allows the seeds to pass more easily through the digestive tract of animals, which aids in seed dispersal, or when sitting in the ground during the winter.
Teosinte was originally classified as a different genus but DNA analysis tells another story. It reveals a very close relationship to corn, one so close that the two plants are able to cross-pollinate and produce viable, not sterile, offspring. Because of a mutation to the tga1 (teosinte glume architecture 1) gene, the glume of the teosinte seeds receded to form the now familiar cob and exposed the easier to eat kernel. Teosinte has a shattering rachis that falls apart and releases it seeds when it reaches maturity just like early forms of wheat. Maize, on the other cannot disperse its own seeds. Without people to detach the seeds from the cob, the plants would not survive.
When talking about maize, the biggest question we are left with is this: Did people actually consume teosinte? Many researchers question whether they ever did. It would have been challenging for our ancestors to free the seeds from the stone-like glume. The yield of edible materials extracted from the seeds would have been extremely low. This leaves us with an evolutionary conundrum. If teosinte seeds were not consumed, why would our ancestors selectively harvest and plant teosinte seeds? How did they know they could develop it into a food source? It would have taken hundreds, if not thousands of years for the genetic changes, which transformed teosinte to maize, to occur. Why would generation after generation go through the trouble of planting seeds that were inedible? Did they know something in advance?
We will never know firsthand why our ancestors abandoned their hunter/gatherer lifestyle and exchanged it for an agrarian one. Was it part of our social evolution or did some outside influence spur on its development? Likewise, was the transformation of wheat and corn a natural occurrence or was it a gift from the gods? In time, researchers may discover that these changes, while appearing to be sudden, strange and seemingly miraculous, were anything but natural.
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