in the millennia predating biblical times, twenty-eight-chromosome emmer wheat (Triticum turgidum) mated naturally with another grass, Triticum tauschii, yielding primordial forty-two-chromosome Triticum aestivum, genetically closest to what we now call wheat. Because it contains the sum total of the chromosomal content of three unique plants with forty-two chromosomes, it is the most genetically complex. It is therefore the most genetically ‘pliable’, an issue that will serve future genetics researchers well in the millennia to come.
Over time, the higher yielding and more baking-compatible Triticum aestivum species gradually overshadowed its parents einkorn and emmer wheat. For many ensuing centuries, Triticum aestivum wheat changed little. By the mid-eighteenth century, the great Swedish botanist and biological cataloguer, Carolus Linnaeus, father of the Linnean system of the categorisation of species, counted five different varieties falling under the Triticum genus.
Wheat did not evolve naturally in the New World, but was introduced by Christopher Columbus, whose crew first planted a few grains in Puerto Rico in 1493. Spanish explorers accidentally took wheat seeds in a sack of rice to Mexico in 1530, and later introduced it to the American southwest. The namer of Cape Cod and discoverer of Martha’s Vineyard, Bartholomew Gosnold, first took wheat to New England in 1602, followed shortly thereafter by the Pilgrims, who transported wheat with them on the Mayflower.
The Real Wheat
What was the wheat grown ten thousand years ago and harvested by hand from wild fields like? That simple question took me to the Middle East – or more precisely, to a small organic farm in western Massachusetts.
There I found Elisheva Rogosa. Eli is not only a science teacher but an organic farmer, advocate of sustainable agriculture and founder of the Heritage Wheat Conservancy (www.growseed.org), an organisation devoted to preserving ancient food crops and cultivating them using organic principles. After living in the Middle East for ten years and working with the Jordanian, Israeli and Palestinian GenBank project to collect nearly extinct ancient wheat strains, Eli returned to the United States with seeds descended from the original wheat plants of ancient Egypt and Canaan. She has since devoted herself to cultivating the ancient grains that sustained her ancestors.
My first contact with Ms Rogosa began with an exchange of emails that resulted from my request for two pounds (900 grams) of einkorn wheat grain. She couldn’t stop herself from educating me about her unique crop, which was not just any old wheat grain, after all. Eli described the taste of einkorn bread as ‘rich, subtle, with more complex flavour,’ unlike bread made from modern wheat flour, which she claimed tasted like cardboard.
Eli bristles at the suggestion that wheat products might be unhealthy, citing instead the yield-increasing, profit-expanding agricultural practices of the past few decades as the source of adverse health effects of wheat. She views einkorn and emmer as the solution, restoring the original grasses, grown under organic conditions, to replace modern industrial wheat.
And so it went, a gradual expansion of the reach of wheat plants with only modest and gradual evolutionary selection at work.
Today einkorn, emmer, and the original wild and cultivated strains of Triticum aestivum have been replaced by thousands of modern human-bred offspring of Triticum aestivum, as well as Triticum durum (pasta) and Triticum compactum (very fine flours used to make cupcakes and other products). To find einkorn or emmer today, you’d have to look for the limited wild collections or modest human plantings scattered around the Middle East, southern France, and northern Italy. Courtesy of modern human-designed hybridisations, Triticum species of today are hundreds, perhaps thousands, of genes apart from the original einkorn wheat that bred naturally.
Triticum wheat of today is the product of breeding to generate greater yield and characteristics such as disease, drought and heat resistance. In fact, wheat has been modified by humans to such a degree that modern strains are unable to survive in the wild without human support such as nitrate fertilisation and pest control.3 (Imagine this bizarre situation in the world of domesticated animals: an animal able to exist only with human assistance, such as special feed, or else it would die.)
Differences between the wheat of the Natufians and what we call wheat in the twenty-first century would be evident to the naked eye. Original einkorn and emmer wheat were ‘hulled’ forms, in which the seeds clung tightly to the stem. Modern wheats are ‘naked’ forms, in which the seeds depart from the stem more readily, a characteristic that makes threshing (separating the edible grain from the inedible chaff) easier and more efficient, determined by mutations at the Q and Tg (tenacious glume) genes.4 But other differences are even more obvious. Modern wheat is much shorter. The romantic notion of tall fields of wheat grain gracefully waving in the wind has been replaced by ‘dwarf’ and ‘semi-dwarf’ varieties that stand barely a foot or two tall, yet another product of breeding experiments to increase yield.
SMALL IS THE NEW BIG
For as long as humans have practised agriculture, farmers have strived to increase yield. Marrying a woman with a dowry of several acres of farmland was, for many centuries, the primary means of increasing crop yield, arrangements often accompanied by several goats and a sack of rice. The twentieth century introduced mechanised farm machinery, which replaced animal power and increased efficiency and yield with less manpower, providing another incremental increase in yield per acre. While production in the United States was usually sufficient to meet demand (with distribution limited more by poverty than by supply), many other nations worldwide were unable to feed their populations, resulting in widespread hunger.
In modern times, humans have tried to increase yield by creating new strains, crossbreeding different wheats and grasses and generating new genetic varieties in the laboratory. Hybridisation efforts involve techniques such as introgression and ‘back-crossing’, in which offspring of plant breeding are mated with their parents or with different strains of wheat or even other grasses. Such efforts, though first formally described by Austrian priest and botanist Gregor Mendel in 1866, did not begin in earnest until the mid-twentieth century, when concepts such as heterozygosity and gene dominance were better understood. Since Mendel’s early efforts, geneticists have developed elaborate techniques to obtain a desired trait, though much trial and error is still required.
Much of the current world supply of purposefully bred wheat is descended from strains developed at the International Maize and Wheat Improvement Center (IMWIC), located east of Mexico City at the foot of the Sierra Madre Oriental mountains. IMWIC began as an agricultural research programme in 1943 through a collaboration of the Rockefeller Foundation and the Mexican government to help Mexico achieve agricultural self-sufficiency. It grew into an impressive worldwide effort to increase the yield of corn, soya and wheat, with the admirable goal of reducing world hunger. Mexico provided an efficient proving ground for plant hybridisation, since the climate allows two growing seasons per year, cutting the time required to hybridise strains by half. By 1980, these efforts had produced thousands of new strains of wheat, the most high-yielding of which have since been adopted worldwide, from Third World countries to modern industrialised nations, including the United States.
One of the practical difficulties solved during IMWIC’s push to increase yield is that, when large quantities of nitrogen-rich fertiliser are applied to wheat fields, the seed head at the top of the plant grows to enormous proportions. The top-heavy seed head, however, buckles the stalk (what agricultural scientists call ‘lodging’). Buckling kills the plant and makes harvesting problematic. University of Minnesota-trained geneticist Norman Borlaug, working at IMWIC, is credited with developing the exceptionally high-yielding dwarf wheat that was shorter and stockier, allowing the plant to maintain erect posture and resist buckling under the large seed head. Tall stalks are also inefficient; short stalks reach maturity more quickly, which means a shorter growing season with less fertiliser required to generate the otherwise useless stalk.
Dr Borlaug’s wheat-hybridising accomplishments earned him the title of ‘Father of the Green Revolution’ in the agricultural community, as well as the Presidential Medal of Freedom, the Congressional