Redesigning Life is the title of a 2016 book by Dr. John Parrington, Associate Professor in the Department of Pharmacology at Oxford University in England. It’s a detailed and fascinating book about how DNA, the rulebook of life, is organized and functions, and how all life forms can be changed through insertion or editing of genes. Insertion of genes, of course, fell out of favor with politicians and the general public after Monsanto created crops that tolerated Roundup.
The ability to change the course of evolution has been the desire and dream of farmers and academics for thousands of years. I wrote previously about how Stone Age hunters and gatherers were likely the first to manipulate evolution, though unwittingly. Wild grains were prone to shatter, because that’s the first step in ensuring the continuation of the species. Gathering the seeds that had not yet shattered promoted the non-shattering trait in seeds spilled close to their shelter, while the shattering rate of grain left in the wild increased. Observation of this difference by someone probably (my speculation here) led to saving some gathered seeds for planting by their shelter. The next probable observation was that disturbing the ground and covering the seeds resulted in better stands, and farming was born. Once domestication began, it would be natural for a farmer to select seeds from plants with the most desirable characteristics for seeding the next crop.
The story of Jacob in the Bible tells of an ancient attempt to manipulate traits. Jacob had tended the flocks of his uncle Laban for 14 years without pay to earn the right to marry Laban’s daughters, first seven years for Leah, and seven more for Racheal, the daughter he really wanted.
After 14 years, Jacob’s obligation was complete, but Laban wanted him to continue. So they made a deal. Laban’s sheep were mostly white, but a few were black or spotted. Jacob offered to keep herding Laban’s flock without pay if Laban would give him all the spotted and black sheep now in the flock and all future lambs that were black or spotted (Genesis 30: 26-43). Laban agreed.
So Jacob took some poplar boughs and peeled some of the bark away so they appeared spotted or striped. Then he placed the boughs near the watering troughs where Laban’s ewes would see them and be encouraged to bear spotted or black lambs. His plan worked: The frequency of spotted and black births went up, and Jacob became very wealthy.
We know, of course, that what the ewes saw had nothing to do with it: It was all in the genetic makeup of the flock, and the gene scramble at insemination turned in Jacob’s favor.
Until the turn of the 20th century, new varieties arose through farmer selection, resulting in landraces adapted to local conditions. Occasionally a mystifying new species or trait would appear as a mutant or sport. Such changes were exceedingly rare. Then, in 1895, X-rays were discovered by Wilhelm Rontgen, and in 1898 Marie Curie discovered mysterious emanations from radium that we now call radiation. Within 10 years these rays were being put to use in medical, chemical, and biological experimentation.
X-raying plants caused all sorts of changes. Plant breeders became excited about the possibility of controlling evolution and produce new grains, fruits and vegetables, and increase yields on all crops. Their enthusiasm was magnified by the press, which bombarded the general public with stories of fantastical crops in the future.
X-ray machines were purchased by plant breeders and put to work in the field and the laboratory. General Electric, the primary builder of X-ray machines, set up its own laboratory for plant experimentation, hoping to create a large new market for their machines.
These experiments with X-rays and radium continued well into the 1930s, as did the hyperbolic stories in magazines and newspapers. But hopes to control evolution never materialized: Responses were universally negative, except for flowers. Burpee Seed Co. was able to monetize changes in flower color, leaf appearance, or growth habit resulting from x-ray bombardment.
Meanwhile, agronomists at land-grant universities steadily improved crops through crosses and backcrosses.
After World War II, experiments with high energy isotopes from nuclear reactors began to produce useable results. Over 1,000 food and flower varieties around the world now owe their existence to scrambling their chromosomes and mutilating their genes with radiation. Ruby Red grapefruit is an example of a fruit produced with the help of radiation. Research in this area goes on, but receives no public outcry despite the massive damage to the genome required to harvest a useable trait. Sadly, genes added, deleted, or modified by methods that do not disturb the remainder of the genome are subjected to massive and sometimes violent opposition by a public that is taught to fear GMOs as unnatural and dangerous. Ignored is the fact that natural mechanisms have been adding, deleting, mutating (changing, creating) chromosomes and genes for 3 billion years to give us the species now occupying earth.
In the late 1930s, while experimenting with chemical mutagens, it was discovered that the plant alkaloid colchicine applied to geminating seeds could double the number of chromosomes, turning the normal genome of one set of chromosomes from each parent (diploid genome) to two sets from each parent (tetraploid genome). Plants thus treated often displayed extra vigor, larger fruit, and greater yield. Again, this discovery produced great excitement in academia and the media that a method of guiding evolution had been discovered. Hope was again shattered when such treatments were found to have limited use. Some plants succumb to this treatment and their progeny have become useful varieties: Others respond negatively or not at all. Triticale, an infertile cross between wheat and rye, was made fertile by doubling the chromosomes.
One use for colchicine has been to induce parthenocarpy, the development of fruit without seeds. If a diploid watermelon, for instance, is crossed with a tetraploid watermelon, a triploid plant is produced in which flower fertilization fails but the fruit develops anyway, without seeds. Seedless fruits, such as navel oranges are produced this way, and a seedless tree can be propagated vegetatively. Watermelons, though, require seeds for planting, so crosses must be made every year.
The thing that saddens me is that the hope long held that evolution could be controlled and enhanced is finally achievable through genetic engineering, and it is widely rejected to the detriment of the world’s hungry.
Jack DeWitt is a farmer-agronomist with farming experience that spans the decades since the end of horse farming to the age of GPS and precision farming. He recounts all and predicts how we can have a future world with abundant food in his book “World Food Unlimited.” A version of this article was republished from Agri-Times Northwest with permission.
