Thursday, November 22, 2007

Don't be a turkey

For all readers in the United States, Happy Thanksgiving; for everyone else, happy Thursday.

I'm taking the day pretty much off, but I am minded to drop a thought on turkeys and, more generally, killing things to eat them. In short form: we don't have to, and it is wrong to kill without need. (Whether it is always acceptable to kill with need is a far more complex question, but irrelevant here.)

The long form is something like this. There is a surprising disjunct between our biology and our history: we evolved as omnivores, but omnivores who relied heavily on meat; but our history, once we became true humans, is that of omnivores who eat little or no meat--and that is not a modern trend, but one that begins as far back as we can reckon, at least through the early hunter-gatherer stages at the dawn of humankind. Indeed, if we looked only at the historical dietary proportions of meat to vegetable matter, it would be almost literally incredible to realize that we are natural meat-eaters. (See Haim Ofek, Second Nature: Economic Origins of Human Evolution.)

But, while we seem to have come from a line of meat-eaters, there is a curious discrepancy: the proportions of our guts--the ratio of small intestine to the entire digestive tract--suggests meat-eater, but our tracts as a whole are remarkably small for our body size, about 60% of what would ordinarily be expected.

Very obviously, we can not only survive but thrive on a meatless diet, in that much of humankind has done so for long ages now, all the while turning out advanced societies. How to reconcile those disparate data? One popular theory is that we in essence traded gut for brain. The remarkably large (in proportion to body size) human brain eats a lot of energy, energy that would otherwise go to supporting other body organs. There are almost no major organs in the human body whose size is not pretty well set by the overall mass of our bodies; the exception is the digestive tract.

Apparently it was a complex dance of inter-relations: as our brains expanded, we acquired the skills to pre-process our food--to peel it, slice it, mash it, cook it, and so on--all of which much reduced the original burdens on our digestive tracts. Such pre-processing allowed a smaller digestive tract to function satisfactorily, which in turn freed up more energy for that expanding brain, and so it went. We ended up with big brains and small guts.

Humankind, starting right from the dawn of the species and the early hunter-gatherers, has lived mainly, often exclusively, on vegetable matter. Meat was, till nearly modern times (which are a minute slice of humankind's history), a scarce ingredient in human diets worldwide.

Only in modern times has it become possible for large numbers of people to add large amounts of meat to their diets. And, because it was originally a mark of wealth and privilege to eat meat, once meat eating became available to the masses it was taken up avidly.

Well, today we know better. The "elegant" white bread is far less nutritious and healthful than the old "peasant" breads. And eating meat is not good for health. I said I'm not going to work hard today, so I am not going to bother to run down the countless links available to show all the severe health disadvantages of heavy meat-eating, from intestinal cancer on down: you can, in the unlikely case that you aren't already familiar with the matter, run the references down yourself. You'll have no trouble. And all that is without consideration of the toxics to be found in meat (which includes fish, with mercury and who knows whatall else), or such joys as the horrid mad-cow disease.

As to the ethics of taking the lives of animals, there are, I suppose, some who think that they have that right. Why one would have a right to take the life of anything not immediately and seriously threatening one is beyond me, so I won't even try to debate the point, as I cannot even see the opposing viewpoint at all.

So we're back to the short form: we don't have to kill things to live, so why should we?

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Anonymous said...

Did you know that M John Harrison has a blog, "Uncle Zip's Window"?

Eric Walker said...

I did not: thank you for alerting me. I have added it to the Harrison page at Great Science-Fiction & Fantasy Works.