Mon, 27 Oct 2003

Welcome to Biotechnology's Brave Old World

Henry Miller, Fellow, Hoover Institution, Stanford University, Project Syndicate

Skeptics about agricultural biotechnology lambaste it as unproven, untested, unnatural, and uncontrollable. Nothing could be farther from the truth. On the contrary, neither biotechnology nor genetic engineering are new, and consumers, government, and industry all have had long, extensive, and positive experience with both.

Early biotechnology -- the application of biological systems to technical or industrial processes -- dates to 6000 B.C., when the Babylonians used specialized microorganisms in fermentation to brew alcoholic beverages.

Genetic engineering can be dated from man's recognition that animals and crop plants can be selected and bred to enhance desired characteristics. Early biologists and agriculturists carried out selection for desired traits, generating poorly understood changes in the organisms' genetic material.

Put another way, "nature" didn't give us seedless grapes, the tangelo (a tangerine-grapefruit hybrid), and fungus-resistant strawberries: Farmers and plant breeders did.

During the past half-century, better understanding of genetics at the molecular level has added to the sophistication of the genetic improvement of all manner of organisms.

Opponents of biotech repeatedly raise dire warnings of the movement of "rogue genes" between the modified crop and wild (or domesticated) relatives. But, at the risk of mixing metaphors, this is a red herring.

Gene flow is ubiquitous. All crop plants have relatives somewhere, and some gene flow commonly occurs if the two populations are grown close together. Gene flow from wild relatives to crop plants may even be encouraged by subsistence farmers to maintain the broad genetic base of the varieties that they plant using seed harvested from an earlier crop.

Such gene flow does not occur when farmers buy their seeds from seed producers, of course, but in that case gene flow in the other direction is still possible, with genes from the cultivated crop ending up in the wild relative.

That is most likely if genes from the crop confer a selective advantage on the recipient, an occurrence that is uncommon with gene-splicing, where most often the added gene places the recipient at a natural disadvantage.

The worst-case scenario would be gene transfer from plants engineered for enhanced resistance to certain herbicides. Once the gene has been transferred to the wild relative, there will be a strong selection pressure to maintain it there if the same herbicide is used, making the weedy wild relatives more difficult to control. But even this scenario raises no issues of ecological or food safety. For if the use of one herbicide were compromised, farmers would simply use another.

Gene transfer is an age-old concern for farmers. Growing hundreds of crops, virtually all of which have been genetically improved, the practitioners of "conventional" agriculture in North America meticulously developed strategies for preventing pollen cross-contamination in the field -- when and if it is necessary for commercial reasons.

A good example is Canola -- the genetically improved rapeseed developed by Canadian plant breeders a half-century ago. The original rapeseed oil was harmful when ingested because of high levels of erucic acid.

After conventional plant breeding led to the development of rapeseed varieties with low concentrations of erucic acid, canola oil became the most commonly consumed oil in Canada. But high- erucic acid rapeseed oil is still used as a lubricant and plasticizer. So the high- and low-erucic acid varieties of rapeseed plants must be carefully segregated in the field and thereafter. Canadian farmers and processors accomplish this routinely and without difficulty.

These applications of conventional biotechnology, or genetic engineering, represent monumental scientific, technological, commercial, and humanitarian successes.

But the techniques they were relatively crude and recently have been supplemented -- and in many cases replaced -- by "the new biotechnology," a set of enabling techniques that enable genetic modification at the molecular level.

The prototype of these techniques, variously called gene- splicing or genetic modification ("GM"), is a more precise, better understood, and more predictable method for altering genetic material than was possible previously.

An authoritative 1989 analysis of genetic technologies by the U.S. National Research Council summarized the scientific consensus: "With classical techniques of gene transfer, a variable number of genes can be transferred, the number depending on the mechanism of transfer; but predicting the precise number or the traits that have been transferred is difficult, and we cannot always predict the (traits) that will result. With organisms modified by molecular methods, we are in a better, if not perfect, position to predict (their traits)."

The desired "product" of gene-splicing may be the engineered organism itself -- a bacteria to clean up oil spills, a weakened virus used as a vaccine, or a papaya tree that resists viruses -- or it may be a biosynthetic product of the cells, such as human insulin produced in bacteria, or oil expressed from seeds.

Gene-spliced plants have for several years been grown worldwide on more than 100 million acres annually. More than two- thirds of processed foods in the U.S. contain ingredients derived from gene-spliced organisms. There has not been a single mishap that resulted in injury to a single person or ecosystem. Thus, both theory and experience confirm the extraordinary predictability and safety of gene-splicing technology and its products.

The new gene-splicing techniques have yielded many important new research tools and commercial products, and have only begun to change the way we do biological research and to increase the choices available to farmers, food producers, physicians, and consumers. But they are merely an extension, or refinement, of the kinds of genetic modification that preceded the era of "new bio-technology." So welcome to Biotech's Brave Old World.

The writer was an official of the Food and Drug Administration from 1979 to 1994 and was a member of the OECD Group of National Experts on Biotechnology.