By Tony Trewavas and Keith Dawson
The sweet potato, often called a yam, is a familiar vegetable on our supermarket shelves. It is a swollen root and its orange flesh is rich in the precursor of vitamin A. It provides nourishment equivalent to the potato (although unrelated) but will grow in poor as well as soil-rich circumstances. It has been available for some 20 years and freely sold. If you have eaten sweet potato in the last 20 years you have eaten your first GM meal.
Some 8,000 years ago, a soil bacterium called agrobacterium, inserted two of its genes into the sweet potato genome. These genes are expressed and have been found in all domesticated yams but not in closely related wild relatives indicating humans are responsible for selecting this GM crop. Since we know these genes in other plant species modify the growth of the root by changing hormone levels, it doesn’t take much imagination to see that selection, those thousands of years ago, was probably on root size somewhere in the South American highlands.
GM opponents have claimed that all sorts of calamitous circumstances would follow GM crops, on human health and ecosystem stability that such genes would career through the natural world destroying all in their wake. Has any of this happened? Of course not. In fact, it hasn’t done anything other than increase the variety of our diet. These GM sweet potatoes are part of the "natural world".
Richard Lochhead, Cabinet Secretary for Rural Affairs, Food and the Environment, claims that Scotland’s food and drink industry has a clean, green image which would be spoiled by GM crops.
The United States, Canada, Argentina and Brazil all grow GM crops extensively, but his assertion has not made an iota of difference to their exports to us of Kellog's corn flakes, rye whisky, Coca Cola, baked beans, Californian wine, cashew nuts, bread wheat and corned beef, to name but a few. Mr Lochhead’s claim is specious and is not backed up by scientific evidence.
But the Scottish Government's ban on growing GM crops means that our farmers are denied choice, as are the public to eat what they produce. Scotland cannot benefit from GM technology just as our scientists cannot seriously consider worthwhile research in this area from what to us looks like superstition, because there is no other justification.
GM herbicide-resistant crops lead naturally to no-till agriculture, a form of farming that stores carbon in the soil instead of having it in the atmosphere; halves nitrous oxide emissions (a greenhouse gas 300 times more potent than CO2); eliminates soil erosion; provides for cleaner rivers; and improves soil quality, water retention and drainage. There are large reductions in machinery use and thus fossil fuel emissions and enormous increases in soil biodiversity and farmland birds that like no-till fields. Introduction of these crops in this country would green and clean much of our agriculture.
Opponents have claimed that the main herbicide in herbicide-resistant crops, glyphosate, is probably carcinogenic. What they don’t say is that the UN committee that made this designation has placed art glass, night shifts, grapefruit juice, hairdressing, tea-bag manufacturing, bacon, sausages, burgers, emissions from fried food and so on in the same category.
Other expert committees disagree and, of course, the question of dose (exposure) opponents ignore (or more probably don’t understand) is crucial to any of this. Half the natural chemicals we consume every day test as carcinogens but only at high doses.
But advances in technology enable scientists simply to move genes within a specific crop plant to new designated places in its own genome, a process identical in all respects, apart from precision, with conventional breeding. This cis-genetic GM procedure will take over much of present plant breeding because of its precision; but not in Scotland.
The eco-modernist manifesto states that decoupling mankind from the natural world, thus ensuring its survival, requires agriculture to be as efficient as possible. These new procedures will accelerate the most efficient use of land while increasing crop yield necessary for a growing world population. But the need is for a that is government open to knowledge, progress, and willing to lead by example and education. It is sadly lacking in this instance.
Professor Trewavas and Dr Dawson, the Scientific Alliance Scotland.