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04 May 2010

More on Genetic Engineering

My previous post garnered some feedback, which I'll reproduce here:

I used to be fully on board with the position that you've taken in this post (thanks to Bullshit!), but then I watched this video:http://www.youtube.com/watch?v=WOMqwPxUx54 and changed my mind.

Please watch it and respond with your thoughts.

Thanks for your comment, Rob. I'm glad that you're willing to change your mind—it's often a difficult thing to do, but it is sometimes necessary to preserve one's intellectual integrity. As someone who has recently started eating vegetarian (I was convinced by this episode of Reasonable Doubts), this is something that I understand. I remember one of the Novellas remarking on an old episode of The Skeptics' Guide that he tries to have no emotional attachment to his beliefs, only to the process by which he arrives at them—I certainly think that this goal is laudable.

In this particular instance, however, I must disagree with your assessment, for I have found insufficient evidence to persuade me to change my views. I don't have time to review the entire video in grisly detail (it seems to suffer in many places from what Eugenie Scott and Steven Novella have called the "Gish Gallop", and I don't have twelve hours to devote to addressing every rapidfire claim), but I will hit some highlights.

The video contains an interview with Jeffrey Smith, who is described by the Institute for Responsible Technology as a "GMO expert". He has written several books, and he apparently also writes for the Huffington Post (a notorious den of quackery which also frequently employs Deepak Chopra, another acclaimed author), and although he claims to have been quoted in Nature and New Scientist, he has not authored or participated in any peer-reviewed research on the subject. I could find no information on his educational background, even on his own site (if I simply missed it, please let me know).

So to begin with, I have no more reason to think that he knows what he's talking about than any random person I meet on the street. But let's take a look at what he has to say.

There are genes from spiders that've been inserted into goat DNA in the hopes that they could milk the goat to get spiderweb protein...

So? What's wrong with that? His premise seems to be missing an argument; but his intention to me seems clear: to scare people with the Frankensteinian exploits of genetic engineers.

They have genes from bacteria that produce its [sic] own pesticide transfered into corn and cotton so that every cell and every bite of the corn produces a toxic pesticide to kill insects.

What Smith fails to mention here is that the bacteria in question (bacillus thuringiensis) affects only insects and closely-related organisms. Bt has been found to be safe in humans.

The genetically engineered foods currently on the market only have two main traits: 80% are designed to withstand doses of herbicide (they don't die when they're sprayed with the company's proprietary herbicide) or they're engineered to produce a pesticide. 99.9% of these crops only have these two traits. But if you listen to the rhetoric by the biotech companies, they claim that the GM foods are going to feed the world's hungry, they're going to reduce pesticides, increase yields, and increase nutrition. In reality the average GM crop reduces yield and the herbicide-tolerant crops have resulted in about 250 million extra pounds of herbicide being sprayed on fields in the United States.

Some of what he says here seems to directly contradict the report from the NRC that I referenced previously. "In many cases, farmers who have adopted the use of GE crops have either lower production costs or higher yields, or sometimes both, due to more cost-effective weed and insect control and fewer losses from insect damage."

But I think that this is an important point: Doesn't it stand to reason that reducing losses due to insect predation will increase crop yields? Smith seems to disagree. The safety of chemical pesticides have been a concern for decades, and Bt is by many accounts a safe and effective alternative. The levels of pesticide deemed safe by the government are often several orders of magnitude lower than those recommended by scientists and medial professionals, just to be safe. (See podcast and references here.)

It's also lost money for farmers in whole sectors, and this has caused the United States government to spend an extra three to five billion dollars per year subsidising the prices of these crops that no one wants overseas and that a greater number of people in the United States are rejecting.

In this instance, I'd question the causal link that he proposes between GE foods and $3–$5 billion in government subsidies. I'm not claiming that GE foods are not a contributing factor, but I'm not aware of any evidence that they are. Farming is a tough business.

I do believe him when he says that "a greater number of people in the United States are rejecting" GE foods (although "Greater than what?" is a question that might be appropriate, here). However this argument from popularity is logically fallacious, and I'm convinced that the fear-mongering of Smith and others like him takes the lion's share of the blame for the "Frankenfoods" scare.

Scientists give the false notion that genetic engineering is just an extension of natural breeding.

Actually, I believe they tend to label it an extension of artificial selection, but that's minutia.

The process of genetic engineering causes massive collateral damage in the DNA of the natural plant. The GM DNA can be two to four percent different, mostly through mutations: unpredicted, unexpected mutations up and down the DNA, different from its natural parent.

I would like evidence that these mutations occur at the rate specified and that they are harmful. Citation needed.

This is a theme that seems to run through the entire interview. Although the rhetoric is obviously persuasive, one of this particular disadvantages of this video (and many others) is the apparent unwillingness of the producers to cite any sources (as contrasted to the show notes of podcasts such as The Reality Check, Skeptics' Guide to the Universe, and others, or the on-screen and off-screen citations and resources provided by other YouTubers such as Thunderf00t). This makes it incredibily difficult and time-consuming to fact-check. To quote the emminent Samuel Clemmens, "A lie can travel halfway around the world while the truth is putting on its shoes."

It turns out ... that the quality and quantity of safety studies is [sic] insufficient to protect the public. ... The overwhelming consensus among the FDA's own scientists were that GM foods were inherently unsafe.

Again, citation needed.

Look: I'm not going to be convinced by a video—unless it is an eminently cited video produced by several people who can demonstrate that they are well-educated in the appropriate fields, and who I can be reasonably sure have no vested interest in either side of the argument. Hey, I know that's a tall order. I'm not going to watch every video that is sent to me (especially if they're more than a few minutes long)—there's a lot of garbage out there, and my time is precious to me. That's why I'd prefer a scientific paper over a video, any day. And it's a hell of a lot easier to quote!

I want to be clear (something that apparently I'm not very good at): I am not saying that all GE foods are safe. I am not saying that organic foods are bad for you. I am not saying that testing new products is unnecessary. And I am not simply siding with biotechnological companies.

What I am saying is that the label "organic" is not scientifically meaningful: it's marketing, like putting vitamins in your shampoo. What I am saying is that GE crops have been shown to provide specific benefits over traditional crops.

I don't think that organic is the solution. I think that cautious progress, full of scientific testing and all of that good stuff, is. I think Ben Goldacre gets it right:

I’m cautious about GM, and each crop needs to be assessed on a case by case basis, but they seem safe overall. If there’s something new and frightening, then I want to see it published, in full, so we can all sit down and get frightened by it together, on the basis of well conducted research that we can see and read. Before that, I’m not sure anyone’s very well served by scare headlines.

And who wouldn't want a goat that you could milk for spider-silk? :)

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