The Evolution of Seed

Human civilisation would not have been possible without the advent of agriculture and the subsequent selective breedings  of plant traits. Today,  we are even able to farm on barren land. This article gives an overview of the evolution of seeds in meeting our food requirements.

Last December, I took a couple of weeks off, and decided to drive around Southern Europe. Since I have friends in several cities, I just took long drives across the region to meet with several of them. This “tour” also offered me the opportunity to enjoy the beautiful countryside. However, one stretch had a different story to tell. This was the journey from Nerja to Valencia in the southeast of Spain pn the toll-free A-7 highway, which on the map would appear as a largely coastal drive of almost 600 kilometers. To my amazement, the view I had for much of the stretch was of greenhouses on both sides of the A-7 (I also had a similar experience in Antalya, Turkey). This is a very hot and almost desert-like region, which over the past thirty odd years has become covered with plastic, and is apparantly distinctly recognisable from space. The largest concentration of greenhouses in the world is said to be near the city of Almeria, where 26,000 hectares produce more than half of Europe’s supply of fruits and vegetables.

The fully hydrophonic systems in the swamps of the greenhouses have brought prosperity to one of Spain’s poorest and barren regions. At the same time, there is significant environmental challenges as well. Discarded plastic sheeting block riverbeds and empty pesticide containers are found everywhere, including in the sea from where a dead sperm whale washed up with 17 kilograms of plastic in its stomach. The advent of agriculture, and the subsequent thousands of years of development in farming technology have been the driving force that allowed human civilisation to flourish. Unfortunately, moral, safety and environmental issues have surfaced in recent years. While we have come to appreciate large and beautiful looking vegetables, we need to take cognisance of the potential risks posed by present agricultural technology, especially the spread of genetically modified (GM) food.

In his book, The Organic Seed Grower: A Farmer’s Guide to Vegetable Seed Production, the veteran plant breeder John Navazio describes seeds as the vital link to our agricultural past. Our ancestors collected wild seeds, and painstakingly turned them into plants that would suit our palates.  Today with the advent of genetically modified organisms (GMO), we are at a crossroad. We need to decide the kind of food crops we want grown, and the type of food we want to consume.  As GMOs can potentially have much bearing on our future food security, I would like to summarise the prevailing debate on it as well as share some of my thoughts on this issue. This brief will present an overview of how seeds evolved over time, and a second article will discuss the issues and challenges surrounding GMO.

For most of the 200,000 years of human history, we were hunter-gatherer; nomads who foraged for food at a place but left for elsewhere once the food ran out. The first human farmers appeared around 12,000 years ago. With the ability to farm, our ancestors no longer needed to move from place to place in search of food. They became settled communities, with their food sources being replenished through plant and animal breeding. With the increased productivity from their crops, there was excess food which could be stored for consumption during the winter months. Seed savings allowed crops to be sown with the arrival of a favourable season. Increased food production also allowed people to specialise in skills, which then led to a better quality of life.

Although the evolution of farming itself varied among different parts of the world, wild species of plants were cultivated first by the early farmers before they started plant domestication some time later. With domestication, wild plants with favourable traits are repeatedly selected for sowing. This is a two-step process. In the first step, called domestication syndrome, plants are made to acquire traits that distinguish them from wild plants so that they can be reliably cultivated and harvested. In the next stage, plants are selected for sowing based on preferred qualities such as size, colour, shape and taste.  For instance, plants with fruits that were larger or juicier may be preferred for replanting. As in the domestication of animals, continuous selection of larger or juicier fruit plants led to descendants that possessed such traits with greater probability. Likewise, wild grass plants, such as barley, wheat, corn and rice that displayed a lower tendency to scattering of seeds, thereby reducing the rate to seeds being blown away by the wind, were also preferred for replanting. Farmers had to go through repeated harvests before they were able to possess a domesticated plant that exhibited their preferred characteristics. As one can easily imagine, civilisation as we know it today would not have been possible without the domestication of both plants and animals.

The famous English naturalist, and whose theory of evolution changed the way we look at living things, Charles Darwin, and the German geneticist, Gregor Mendel, pioneered the hybrid revolution in the nineteenth century. While open pollination allowed plants to pollinate freely, thereby providing genetically diverse plants, hybridisation ensures that the pollen of two different but related plants is crossed to provide a plant with new traits. The latter is the result of human intervention during the pollination process. With open pollination, seeds can be saved by farmers and sown later to produce offsprings that are similar to their parents. This also allows farmers to create heirloom plants. The hybrid seeds known as an F1 hybrid, however, are usually purchased from seed companies.  Farmers will not be able to use the seeds of F1 plants as they are genetically unstable, thereby requiring the farmer to go back to the seed companies to purchase new hybrid seeds. Hybrids have been successful as they create stronger offsprings that also produce higher.

Like hybrids, GMOs are also genetic modification of plants. Hybrid plants are created naturally through pollination with humans controlling the conditions.   Unlike hybrids, GMOs are created in laboratories through gene splicing where a portion of the DNA of a gene in a plant is replaced with a new DNA sequence. Once the new DNA is in place, the function of the gene itself changes. GMO seeds are all patented, while some of the F1 hybrids are also patented. The largest producer of GM seeds is the Monsanto Company, the same company that owns the market leading Roundup pesticide.

While the most sustainable form of farming should be based on open pollination, we also need to recognise the need for efficiency in food production if we are to feed the seven billion world population, which is also growing at a rapid rate. Some degree of artificial selection, or selective breeding, of food specie is surely required. The plants and the animals we humans eat have almost all been modified over the last thousands of years from their wild counterparts. Today we need to pause, though, and decide if we do want to go the GMO way? GM food is banned in several developed countries, with several others having other restrictions in place. Many activists are claiming that it destroys farmers’ livelihoods from both destroying the soil with heavy pesticide use and by creating a dependence on GM seeds as seeds from the plants cannot be saved. The issues are economic and environmental, and we will discuss them in the next part.