to evolutionary biologists, every 'why' question demands four answers:
The four-answer mandate for 'why' questions applies in many realms, but especially in biology. I like my example better: Why does sex feel good? Be advised, I have a scientific reason for my preference. Now, all four answers run parallel to those for the sugar question; however, there is an important distinction to be drawn: Whereas selecting a sweet-tasting substance affords survival value directly to the individual, the pleasures of sex do not.
You might want to read the previous sentence again.In fact, while actually engaged in (I'll use scientific terminology here) chugga chugga kablowie, individuals are decidedly vulnerable to environmental dangers. Sure feels good, though.
The key to the matter, naturally, is that act of fertilization
is mighty important for assuring the perpetuation of genes -- fulfilling
Purpose of Life.
urvival of the individual goes only so far in accomplishing that noble objective. Once those genes get mixed together and passed along, it appears that nature is really done with the individuals who did the fertilizing, hence...
Individuals are altogether vulnerable to environmental hazards while slumbering, too. Sleep, like sex, must confer some kind of powerful fitness indeed to offset the risk. Sleep is when old men do their snoring, but we are not ready to consider our title question just yet.
Life Styles of the PrehistoricThere was plenty of environmental stress outside the Garden of Eden. Let us remind ourselves of what life must have been like for primates, including humans, a few million years ago (or several thousand years ago, if you happen to prefer Bishop Usher's calendar). You were lucky to make it to forty, some say. If your offspring were to prove their reproductive competence, they had to get an early start.
Security for offspring was a top priority -- especially the young female. Her precious uterus is essential for perpetuation of genes. Males were called upon to provide the protection from -- if necessary nourishment for -- predators. Risky business, that. And those guys back then did all that hunting, too, equipped with flimsy weapons. With their propensity for squirting sperms by the gazillions, though, males were expendable. So much so that guy-things included jousting for mates and warfare for territory -- both giving increased evidence for what I said earlier: that sex does not directly benefit the individual, survivalwise. The previous sentence could probably use an exclamation point.
At this point we must take notice of an exceptionally subtle feature of the predator-prey relationship -- a most sophisticated aspect of nature...
The Predator-Prey Contract
There can be no doubt that predators benefit from eating prey. (Are we on the same page here?) Well, the opposite is also true. Partly true. Get this: Prey benefit from being eaten by predators. Not as individuals, for crying out loud -- and unlike sex, it does not feel good, either. But all that matters is that the prey's genes benefit.
Take wildebeests. As a species intent upon propagating genes, wildebeests can achieve that outcome best if certain individuals get gulped by neighborhood lions. Not all -- some. Otherwise, you get a population explosion followed by an environmental crash. So much for perpetuating wildebeest genes.
Less robust animals like those infirmed by disease or other defects -- they would be the preferred individuals for donation to the lion's table. Many have exactly the genes that neither God nor nature would want showing up in the next generation. Others are weakened by age, which means they have already done their gene thing.
Whatever the affliction of the individual, by the way, better that they not run too fast. The faster the chase, the sooner the next chase. The idea is to minimize energy expenditure of the predator (nature often behaves as if it has 'ideas' -- kind of like God). That means fewer prey given up out of a wildebeest population in the long run because of -- well, the short run (for the lions).
An ironic collaboration, therefore, exists between predators and prey. Not always a happy deal, but the result is balance in the environment -- more important, increased fitness for both 'partners' in succeeding generations. We're talking sophistication, here.
Back in those days, gender asymmetry was not a subject for debate. Neither was age discrimination. Accordingly, if young males were less valuable than females, what about old males? We are getting closer to the snoring question. It is old men who put out the most Zs. No question about it: Even today, the vast majority of old men snore. And fat ones do the loudest job of it. Old women don't snore all that much.
ll right then, the proximate answer to our question ("Why do old men snore?" in case you forgot) is that in the vast majority of cases, an old man has a flap of flesh in the back of his throat -- uvula, it's called -- which, when relaxed by sleep, vibrates with the passage of air. Same for an old woman, you might reasonably suppose. Not quite so. Which invites the question, "Why do old women not snore?" Again, the proximate answer is that in the vast majority of cases, an old woman does not have a floppy pallet capable of supporting vibrations.
e have, finally, the phylogenetic answer. God really did a number on old men, some will say. Either that or natural selection was operating. Evolutionists postulate two variations of humans that appeared long ago ('mutations' may be a term to your liking). One carried the requisite genes for the development of the snoring ability in old men and the other did not. We know which one got here. By the billions. The snoring trait must have bred true and conferred a differential advantage in the earliest generations.
If our reasoning is valid, snoring attracted predators. It would not have taken them long to learn that here was an easy meal -- easier than chasing wildebeests in the daytime, anyway. But for us and our genetic imperative, that was cool. Heck, the old guy had long since cut down on his hunting. He had already done his part in reproduction, too -- passing along his snorability genes, let us not forget. As a drain on scarce resources, the snoring old man would be the best choice -- all right, least worst choice -- for his own species to give up, in collaboration with predators. Better him than children or young females -- or, apparently, the old woman sleeping quietly next to him in the cave.
The old woman seems not to have been selected for nighttime sacrifice -- probably because she had a different role to play late in life: assisting mothers in nurturing grandchildren, say. We might suppose that she watched over the tykes in the daytime while their mothers did the gathering. Being not so swift in flight, however, old women would have been selectively ingested by those predators which hunt by daylight and therefore without the need of an auditory invitation.
Meanwhile, a typical old man with floppy glottis got up in the morning after a night of seismic snoring, and performed his own daytime duty, perhaps tagging along with the young males -- to serve as lookout. Or as bait.
In either case, hanging around with a gang of hunters, the codger would have enjoyed some protection from the hazards of the hunt -- at least enough to reach base camp for his nocturnal snoring assignment.
ho cares? After shelters were invented, The Predator-Prey Contract got cancelled. So why do old men still snore? There is only one answer to that question: nature does not care, that's why. Without selective pressure for the removal of the snoring trait, it will doubtless continue in perpetuity. If you are really bothered about snoring, here's what you can do...
Excerpted from The American Heritage Dictionary of the English Language