In Hollywood science fiction, genetic modification leads to monsters with extensible jaws and rampaging epidemics that threaten mankind’s existence. In real-world science fact, altered DNA usually expresses itself more mundanely. Until recently, for instance, it was hard to think of a reason to fear a pasture. But as Matt Jenkins found while reporting this issue’s cover story, “Brave New Hay,” neighbors in Idaho are fighting a pitched battle in the genetic-engineering wars, and alfalfa’s at ground zero.

The alfalfa controversy is part of a complicated process that made its way into the public consciousness a little more than a decade ago. In the mid-1990s, the Monsanto Co., a multinational agriculture and biotechnology giant, introduced the first in a series of crops that had been genetically altered to be resistant to Roundup, the company’s widely used herbicide. With Roundup Ready soybeans, corn, cotton and, now, alfalfa, Monsanto offers farmers and ranchers an alluring opportunity. They can spray, say, an alfalfa field with herbicide; the weeds in the field quickly die, but the alfalfa doesn’t. There’s no need for tilling, and the savings in terms of cost and time are significant.

Because it involves the explicit manipulation of life, genetic engineering tends to polarize, eliciting responses of religious certitude. There are perfectly reasonable people who think it wrong, morally, for humans to tinker with the DNA of any living organism. Leaders in the biotechnology industry, on the other hand, see a world in which genetic modification reduces hunger, cures disease and extends human life.

Between these two poles, farmers near Nampa, Idaho, are fighting out the real-world implications of alfalfa that lives happily after a rousing dousing with weed killer, but that may be spreading its Roundup-resistant gene to nearby “natural” alfalfa fields, whose owners want no part of GM cow feed. There is some evidence that repeated spraying of Roundup Ready crops is producing herbicide-resistant “frankenweeds.” There is a lot of fear of unintended consequences down the road. The battle has gone to the courts, and its ultimate outcome has implications for the biotech and agribusiness industries across the country (not to mention neighborly relations in the West).

I have no reflexive moral aversion to genetically modified agricultural products. The way I see it, man has genetically engineered his farm plants and animals for hundreds of years via selective breeding, mostly for the better. Clearly, though, the biotech revolution has given us the ability to alter life forms quickly and radically. Just as clearly, the U.S. Department of Agriculture has an over-lenient approach to the regulation of GM farm products.

The crops in your neighbor’s field may not jump up and bite you tomorrow. But in an age when even localized changes to the natural world require full environmental impact statements, it seems reasonable that the federal government require an EIS (at the least) before any GM crop or other organism is released, generally, into the environment. When scientists change the script in which the story of life is written, society has the right — and obligation — to edit stringently, in the service of happy endings.