Under The Sun

Wednesday, May 12, 2004

I am not an evolutionary biologist. But one doesn't have to be an expert to solve most, if not all, of these problems. (Link via Donald Sensing.)

>> 1) A fair number of people are deathly allergic to bee stings, going into anaphylactic shock and dying. In any but a protected urban setting, children are virtually certain to be stung many times before reaching puberty. Assured death before reproduction would seem a robust variety of selective pressure.

An allergy is an overreaction by the immune system. Having a strong (=reactive) immune system is good. Dying of pnemonia or infection is just as bad as dying of a bee sting. And I'm not convinced that bee stings are quite that common, especially among people who actually have to pay attention to the world around them in order to survive.

>> The same reasoning applies to a long list of genetic diseases that kill children before they reach adulthood. (Yes, I too can imagine plausible explanations. Plausibility isn’t evidence.)

By itself, no. But there's very strong evidence that the theory of evolution in general is true, so it's reasonable for scientists to conjecture about how it applies to cases on which evidence is lacking.

(I do not, by the way, believe that the theory of evolution is proven beyond any shadow of a doubt. But I do think it's good science, and my religion--Reformed Christianity, to which I converted as an adult--tells me that I should believe good science unless it directly contradicts divine revelation (e.g. Scripture), which evolution doesn't.)

>> Homosexuality in males works strongly against reproduction. Why have the genetic traits predisposing to homosexuality not been eliminated long ago?

(1) There is evidence that homosexuality becomes significantly more common when overpopulation is more likely than extinction. This has been observed in swans, iirc. (2) Genes for homosexual preference are passed on when gays are forced by society to suppress or repress their preferences and therefore often marry and have children. The significant number of "ex"-gays, who are rightly seen as a triumph of will over instinct, are the current incarnation of this. The only way out of this trap is to consign gay men to a celibate priesthood....

(Which may tend to explain why homosexuality has become more common since the Reformation. If it has; I have no data.)

>> Pain serves to warn an animal that it is being injured, or to make it favor, say, a wounded leg so that it can heal. Fair enough. But then why did we evolve the nerves that produce the agony of kidney stones--about which an animal can do absolutely nothing?

Most persons who suffer from kidney stones are past prime reproductive age.

>> the genes exist for the brains of a Gauss or Newton, the phenomenal vision of Ted Williams, the physical prowess of Cassius Clay. Presumably (a tricky word) in a pre-civilized world, strong and intelligent people with superbly acute (for humans) senses would be more likely to survive and spread their genes, leading to a race of supermen. Is this what we observe?

Compared to Cro-Magnons? Absolutely.

>> Here we come to an interesting question: Do the superior pass along their genes more reliably than the inferior? In primitive tribal societies do we observe that the brighter have more children than the not so bright?

It's not clear how much of an advantage above-average intelligence is in primitive tribal societies.

>> evolutionists [] make intellectual pretzels trying to prove that the attractive and the fit are one and the same. Well, they aren’t.

Not anymore. But standards of attractiveness change much more quickly than genes evolve, so that doesn't prove much.

>> If intelligence promotes survival, why did it appear so late?

Because it's very complicated, so it took a long time to develop, and very sophisticated, so it isn't very useful until quite late in the game.

>> People have a wretched sense of smell and mediocre hearing.


>> People are weak. [] Were we already packing heat when we swung down from the trees?

(1) It is quite possible that we were already throwing rocks and sticks. Predators are lazy; two or three rocks is usually plenty. (2) That's why we developed intelligence and tigers didn't. (3) Does anything prey on monkeys?

>> So much of evolution contradicts other parts. Sparrows evolved drab and brown so that predators won’t see them. Cockatoos and guacamayas are gaudy as casinos in Las Vegas so they can find each other and mate.

What eats sparrows? Sparrow-hawks, and other such raptors. Are there any raptors in rain forests? No, because it's impossible to hunt from the air in a rain forest. So it's safe to be eye-catching.

Coming from an anthropologist (archaeologist) you're not bad as an armchair evolutionary biologist. Not entirely right, not entirely wrong -- but, then again, so is the world :) That's the beauty of science & reality.

Mostly, IMHO, people seem to get hung up in teleological thinking. Or confuse the concept of "confers an advantage" with "is necessary, therefore without it you're dead." Face it, as a science, where evolution is concerned, it's pretty difficult to run an experiment against a control ;)
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