Nevertheless, anti-GMO activists have at the ready scattered studies that reinforce their belief that this technology is dangerous. (One favorite, conducted by health researchers in Austria, found reduced fertility rates in third- and fourth-generation mice that had eaten GM corn.) “We do not believe that GMOs have been demonstrated safe for human health and for the environment,” explains Rick North, an educator who leads the Campaign for Safe Food at Oregon Physicians for Social Responsibility. Noting that he’s not an anti-technology “luddite,” North argues—as do many of his fellow anti-GMO activists—that the prospect of negative consequences from GM technology is reason enough not to invest in this area of agricultural science. It’s really about what he calls “the evidence of what we don’t know.”

A small number of studies, however, taken together with the earnest but vague fears expressed by opposition groups, have not proven adequately compelling to policymakers or regulators. “We look at information from all sides,” says Dan Hilburn, administrator of the Oregon Department of Agriculture’s plant division. “We struggle with it, but we’re going to go with the preponderance of the evidence.” The following is only a partial list of those institutions and organizations that have concluded that the GMOs currently on the market are not harmful to the environment or world health: the National Academy of Sciences, Britain’s Royal Society, Europe’s Organization for Economic Cooperation and Development, the United Nations Food and Agriculture Organization, the International Council for Science, the French Academy of Sciences, the British Medical Association, and the German Academies of Science and Humanities. The World Health Organization’s director-general said in 2002 that “WHO is not aware of any scientifically documented cases in which the consumption of these foods has negative human health effects.”

On the environmental side, the United Nations and other organizations have arrived at similar conclusions. In Starved for Science: How Biotechnology Is Being Kept Out of Africa, author and Wellesley College professor of political science Robert Paarlberg gathers together some of the biggest studies of GMOs, including one from 2007 that surveyed 10 years’ worth of research, articles, books, and national and international reports. His conclusion? “The data available so far provide no scientific evidence that the cultivation of the presently commercialized GM crops has caused environmental harm.”

But comparing GM corn and GM trees is like comparing, well, apples and oranges. With crops like corn, the stalks are cut down at the end of the season and that’s it. Dead. Next year’s crop requires new seeds. But poplar trees, like bentgrass, are wind-pollinated perennials, so they could migrate—off of a tree farm, for instance—and spread their genes. “The underlying concern about Steve’s work,” explains Jud Isebrands, owner of Wisconsin-based Environmental Forestry Consultants, “is that if we deploy the transgenics at the commercial scale, they could jump over into the native forest.” That situation would be terrible if, for example, genes for fast-growing poplars somehow spread into wild populations of another species that is already considered weedy. Such a jump may have the ring of a Michael Crichton plotline to it, but in the eyes of scientists, the potential hazards of these crops should be assessed just like any other agricultural innovation. In other words, the potential threat posed by a GM crop doesn’t have anything to do with the fact that it was developed by way of gene splicing; it has to do with whether the traits conferred might cause problems, and whether those traits could move into species where we don’t want them to be. “New technologies for farmers are sometimes good, sometimes bad,” says Strauss. “Scientists will say, ‘Keep options on the table.’ Why isn’t that a good thing?”

The poplars growing in one of Strauss’s test plots, for instance, are engineered to contain lesser amounts of a compound called lignin. An essential constituent of most woody plants, lignin is also a scourge of the paper industry, which uses harsh chemicals to separate it from the wood. (US wood-pulp production exceeds 80 million tons a year, but in the process, the industry has to extract 30 million tons of lignin from the wood.)

The sulfury smell we sometimes wake up to in Portland? That’s from the sulfides used to remove lignin at the paper mill in Camas, Washington. A few years ago, Strauss set out to test whether trees could survive with less lignin, perhaps someday leading to a dramatic reduction in the amount of chemicals needed to manufacture paper.