Neil deGrasse Tyson recently argued that liberals should "chill out" about genetically modified foods. Humans have been altering crops through various breeding methods for many thousands of years, he said — and genetic engineering isn't fundamentally different:

Practically every food you buy in a store for consumption by humans is genetically modified food. There are no wild, seedless watermelons. There's no wild cows. … We have systematically genetically modified all the foods, the vegetables and animals that we have eaten ever since we cultivated them. It's called artificial selection.

Not everyone's convinced, though. Over at Mother Jones, Kevin Drum called this the "lamest defense of GMO foods ever"*:

It's true that we've been breeding new and better strains of plants and animals forever. But this isn't a defense of GMO. On the contrary, it's precisely the point that GMO critics make. We have about 10,000 years of evidence that traditional breeding methods are basically safe. That's why anyone can do it and it remains virtually unregulated. We have no such guarantee with artificial methods of recombinant DNA.

But Drum's objection above isn't quite right. "Traditional breeding methods" for crops have actually changed a lot over time — they haven't just remained static for 10,000 years. And GMOs don't appear to be any riskier than some of these modern conventional techniques that go largely unregulated.

Radiation breeding is considered "conventional"

A good example of this is what's known as "mutation breeding" or "radiation breeding." Ever since the 1920s, scientists have been exposing seeds to ionizing radiation or chemicals in order to induce random mutations. Some of the resulting mutant plants end up having desirable traits.

Increasingly, the line between breeding and biotechnology is getting fuzzier

This isn't some sci-fi fantasy. More than 2,500 varieties of plants bred through mutagenesis have been released since the 1930s — including rice, wheat, barley, peas, sunflowers, peanuts, grapefruit. There are even organic foods produced using mutation breeding, such as Rio Red grapefruits.

This is considered a "conventional" breeding technique — it's not regulated the way GMO foods are, which is why companies like BASF and Monsanto are turning toward it. But mutation breeding obviously hasn't been around for 10,000 years, either.

And, as many scientists have pointed out, it's bizarre that GMOs are widely considered "dangerous" while mutation breeding is largely unregulated in the United States. The National Research Council has noted that, if anything, mutation breeding has a higher risk of producing unintended effects than genetic engineering does — it's even riskier than transferring, say, bacterial DNA into a plant genome.

Now, the point here is not that everyone should go freak out about mutation breeding. The point is that "conventional" crop breeding is often be a messy process. The risk of random mutations and unexpected outcomes has long been present. And what numerous scientific advisory panels have concluded is that genetic engineering isn't inherently riskier than conventional breeding.

Some food regulators — like those in Canada — have dealt with this fact by focusing instead on the novel traits that a new crop has, rather than the specific techniques used to produce those traits. Other scientists have likewise argued that new crops should be considered on a case-by-case basis, rather than assuming that all "conventional" crops are safe and all "GMO" crops are risky.

That's arguably a clearer way to think about these issues. Increasingly, the line between conventional breeding and biotechnology is getting fuzzier — not least as companies use molecular markers and other tools to improve crossbreeding. It's not quite right to say that "genetic engineering" belongs in its own special category.

* Note: I should add that Kevin Drum's post makes some smart points and he later agrees that "GMO breeds created under our current regulatory regime are basically safe to eat." I'm mostly just nitpicking one bit here.

Further reading

By the way, here's a longer, more nuanced Facebook post by Neil deGrasse Tyson elaborating on his GMO argument. He notes that there may well be other reasons to oppose GMOs, but asks opponents to state those reasons more clearly: