Sunday, 29 November 2009

Heirlooms & Hybrids

I talked a lot about varieties of heirloom vegetables this summer, as opposed to the ubiquitous hybrids that crowd our grocery store shelves. Or is that really true? Are heirloom vegetables not hybrids? Are hybrids not eligible to be heirlooms? What's the difference?

The first question then is, what is a hybrid, exactly? Dictionary.com describes it as "the offspring of two animals or plants of different breeds, varieties, species, or genera, esp. as produced through human manipulation for specific genetic characteristics."

There are two problems with this definition; the first is that it is actually quite accurate. The second is that it is also breathtakingly vague. Offspring of breeds, varieties, species or genera? Well that covers the waterfront. Cross two of just about anything, then, and you've got a hybrid, more or less. So why do some things get described as hybrids, and other things not? Like so many things, it boils down to politics and laziness, or at least verbal shorthand.

It's pretty safe to say that when we talk about hybrid vegetables, they are almost always crosses between varieties. It's definitions 6 and 7 that are pertinent to vegetables. In fact, I would be inclined to combine them and say that, when it comes to vegetables, a variety *is* a plant produced by selection to form a category within a species, based on some hereditary difference. New varieties, then, are created by crossing other older varieties, or very occasionally other but related species. Once the cross is sufficiently stable that the offspring of the offspring of the offspring are reasonably uniform in quality, you have a new variety. This process of crossing and selecting to create new varieties has been going on for milennia, and the varieties that are "old" may be known as heirlooms. Old in this case meaning that they've been around for a hundred years or so, or perhaps even less.

Hey, wait! I've just said that heirlooms are hybrids.

Ayup. Sorta.

Once a hybrid vegetable is reliably reproducing offspring similar to itself - a process achieved by people with more knowledge of plant breeding than me - we tend to forget it's a hybrid, and reserve the term strictly for crosses which do not reliably reproduce offspring similar to the parents. There's a whole bunch about that process here; it's pretty technical but what it boils down to is that the varieties we call hybrids tend not to produce offspring of similar quality as themselves, and thus whoever wishes to grow said variety must go back to the producer of the hybrid each year for new seeds. It isn't feasible to produce seed yourself. In short, the problem is not whether a plant is a hybrid or not, the problem is who has control of the means of production - a concept that didn't used to apply to vegetables. If you could raise a plant to reproductive maturity, you had seeds. If not exactly easy-peasy, then at least accessible to everyone with a garden, some basic skills and co-operation from the weather.

A lot of people want to confuse hybrids with genetically modified organisms, but they are not the same thing. Plant hybridization simply involves acting as a matchmaker to plants which might not otherwise meet in nature, but letting natural reproductive processes take it from there. Genetic modification, or engineering, requires direct interference into the genes, often moving DNA from one species to another, in a way that would simply not be possible in nature.

There is a lot of question about what the long term effects of this sort of playing god will have. Proponents swear up and down that it's safe, but pretty much by definition, we just don't know. If it turns out to have been a crap idea - and there's a certain amount of evidence pointing in that direction - well, oops, too bad, so sad.

But as far as I'm concerned, the real problem with genetically modified organisms is obvious: it takes food access out of the hands of anyone who can farm or garden, and puts it SOLELY in the hands of the corporations who own the patents on the modified genetic material and the plants and animals in which it is inserted.

It doesn't take any knowledge of science to see that that is a recipe for complete and utter disaster on a four-horsemen-of-the-apocalypse scale: a little knowledge of human nature will be quite sufficient.

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