Pam Ronald smiled down at her infant son as he squirmed in her arms.
"Feed him baby food made from genetically engineered crops? Oh sure, but I wouldn't give him baby food made from crops with pesticide residues," she said firmly.
A UC Davis professor who studies the molecular basis of plant diseases and the first person to clone a gene for disease-resistance in rice, Ronald is married to an organic farmer and is a staunch supporter of both organic agriculture and biotechnology.
"I would like to see a new category of genetically engineered, organically grown food," she explained. "I believe in consumer choice."
Hers is a strikingly centrist position on an intensely polarized topic-the use of genetic engineering to alter agricultural crops.
Controversy over genetically engineered or modified crops climaxed in Europe in 1999 in a wave of protests that flowed back to the United States, triggering numerous acts of vandalism against agricultural research firms and universities. In four separate incidents from July through September, anti-genetic engineering activists claimed responsibility for destruction of research crops at UC Davis, most of which were not genetically engineered.
"We thought we had dealt with all of this 10 years ago," said Martina McGloughlin, director of the UC Davis Biotechnology Program, noting that for nearly a decade genetically modified crops have been grown on campus without incident. Earlier efforts at public education seemed to have paid off in widespread public acceptance of genetic engineering in agriculture.
So why the sudden shouts of "Frankenstein foods" from an apparently small but vocal group of activists? The current controversy is best understood by tracing genetic modification to its origin.
Tinkering with genetic makeup through crossbreeding
Scientists remind us that for thousands of years humans have been tinkering with the genetic makeup of both plants and animals through selective crossbreeding. But the highly precise techniques that now make it possible to readily transfer specific genes were unheard of just 30 years ago.
In the early 1970s, researchers discovered how to use enzymes to chemically cut pieces of the elegantly spiraled DNA molecule and move those genetic snippets into other cells. The process was called "recombinant DNA" and thus was born modern genetic engineering.
Researchers worldwide quickly realized the power of the new technology and feared it might entail unforeseen risks. In 1974, scientists, concerned about the potential consequences of their work, called for an international conference on recombinant DNA (commonly known today as genetic engineering) and a voluntary moratorium on any experiments that might introduce foreign genes that would result in antibiotic resistance or bacterial toxins.
In 1975, 140 scientists from 17 nations gathered in Pacific Grove for the now-famous Asilomar Conference on the potential risks of recombinant DNA. Participating scientists called on governments around the world to adopt guidelines regulating recombinant DNA experiments.
Research proceeded and scientists learned how to move genes between plants, animals and microbes. Yet while the research community became increasingly confident in the safety of genetic modification techniques, some members of the public retained a latent distrust of the technology, a distrust that has recently flourished in Europe.
Europe's history of food-safety disasters
"Europeans have had quite a history of food-safety disasters, including mad cow disease," said Christine Bruhn, a UC Davis food-marketing specialist who studies consumer attitudes toward biotechnology. She noted that British consumers will not soon forget that, in the late 1980s, government officials assured them their nation's food supply was not threatened by the epidemic of the deadly neurological disease bovine spongiform encephalitis or mad cow disease.
Just a few years later, scientists presented evidence that a new variant of Creutzfeldt-Jakob disease in humans might be caused by prions, proteins that exist in the brain and are thought to be responsible for mad cow disease. To date, more than 51 Europeans have died of the Creutzfeldt-Jakob disease. Whether their deaths were due to consuming infected beef may never be known conclusively, but the experience was enough to shake many Europeans' faith in government assurances related to food safety.
Against that backdrop, it is not surprising that fears over genetic modification found fertile soil in Europe.
Controversy focuses on crops
Most of the controversy over agricultural biotechnology has been focused on crops, perhaps because the technology has advanced much more quickly in plants than in animals. Today at UC Davis, more than 200 scientists are conducting plant-related genetic modification research while a much smaller cadre of researchers is doing similar work with livestock.
"Currently, there are no transgenic animals being used in agriculture anywhere in the world," said UC Davis researcher Jim Murray, who with colleague Gary Anderson is doing genetic engineering research with sheep, goats and pigs. The two animal scientists hope to develop new technologies for moving genes between the different animal species and eventually improve the quality of cows' milk.
For several years, about half of California's dairy cows have received injections of the growth hormone BST, produced by recombinant DNA technology, to boost milk production. But the cows and their milk are not genetically modified.
"BST milk contains very small amounts of the recombinantly produced growth hormone, but the recombinant molecule is indistinguishable from the cow's own growth hormone, which is also present in milk," Anderson explained.
The other widely used genetically engineered ingredient in an animal-based food product is chymosin, a milk-clotting enzyme used to make cheese. Before transgenic chymosin was developed by inserting a calf gene into bacteria, the enzyme had to be extracted from the stomachs of slaughtered calves. Now it is simply harvested from fermentations of the genetically engineered bacteria.
A genetic research boom
While research and commercialization of genetically engineered livestock have proceeded slowly, due to cost and time requirements, work on genetically modified crops has grown rapidly. More than 40 new agricultural products, ranging from pest-resistant corn to herbicide-tolerant soybeans to tomatoes with a longer shelf life, have received federal approval and can now be marketed commercially. By 1999, 57 percent of soybeans, 65 percent of cotton and 38 percent of corn grown in the United States were genetically modified.
This rapid genetic boom alarms critics of the new technologies who fear that, in the rush to commercialize new products, potential risks to human health and the environment will be overlooked. And they question the ethical, economic and social soundness of genetic modification.
For many, the newfound ability to transfer genes not only between species but also from animals or bacteria to plants is just too far removed from the way nature does business.
"But the genes in people, wheat and fish are not all that different," said Cal Qualset, a retired agronomy professor and director of the UC Genetic Resources Conservation Program. "The physiological functions produced by these genes are all very similar. There is a great unity of life that people need to understand."
"Plus, we've been going around nature for years," said Dave Gilchrist, a plant pathologist and associate director of the campus's Center for Engineering Plants for Resistance Against Pathogens. "If you use the argument that genetic engineering isn't nature's way, then you have to reject any conventional breeding of plants or animals because it also is a science-directed process."
Furthermore, Gilchrist and other researchers maintain that genetic engineering is much more precise than traditional breeding-far less likely to transfer unwanted traits to the modified plant or animal.
Next week: Environmental concerns and human health risks from genetically modified organisms are explored. This story originally appeared in UC Davis Magazine's spring 2000 issue.