Tuesday, November 8, 2011

More things difficult to explain from a Darwinian or a folk animal husbandry frame

Most people who think seriously about HBD tend to view it from either a Darwinian frame of reference or from the frame of what I'll call folk animal husbandry.  Folk animal husbandry tends to talk about things like 'the apple not falling far from the tree'---an expression, which, if you think about it, implies pretty strongly a strong central tendency based on genetics with some variation due to randomness and environment, especially when the modifier, the wind wasn't blowing too hard when that apple fell from the tree, is applied.  In addition the expressions about 'good stock' (sometimes 'good pioneer stock', with the stipulation that 'the cowards never came, the weak died along the way' applied) abound in the language.

For most practical HBD purposes, these frames are equivalent.  Honestly, creationists are more likely to agree to the practical application of HBD than are evolutionists, probably due to memetic entanglements.
Most creationists, for instance, will not dispute the claim that the races are partially inbred families writ large.  The ones who know their Old Testament will even point out the particular pedigrees involved going back to Noah.  Most also won't dispute the claim that different families have different tendencies towards large or small endowments in various attributes.  The ones who are lower case o orthodox won't even balk when one points out that said endowments are not fair in any human sense of the word---there's no point-based character generation going on here, God is not a Champions or Hero system gamemaster.  Those with a good practical command of Scripture will quote 'Hath not the potter power over the clay, to make one vessel unto honor and another unto dishonor?'  It's also not unlikely that the Parable of the Talents will be shared with you.  The creationist feels no need to pretend equality in any human sense, because he is confident that human beings are of equal (or at least inestimable) value to God. 

But whichever frame one chooses, one has two huge problems to deal with---two huge brute facts that challenge our frame.

The first is alluded to by a commentator on the 'Final Judgment of Darwin' on homosexuality.  The evidence that the trait is partially influenced by genetics is reasonably strong, but the depression in TFR that it causes is extremely strong.  Using either frame of reference, one would predict that it would be rapidly extinguished from the population, even leaving aside the impact of various 'social diseases', pogroms, or the like.

The second one is the massive differences that exist between women in terms of fertility and ability to safely carry a child to term.  Presumably, if Darwin or animal husbandry optimize ANYTHING, they optimize the ability to produce offspring.  That's about as fundamental as it gets.  Yet we have women like, say, my wife, mother, or great great grandmother who have had no significant difficulties whatsoever bringing a fair number of descendants into the world.  On the other side, we have women like two of my sisters in law who have had a great deal of such difficulty, one of whom would not survive a pre-modern childbirth.  Similar differences exist in terms of ability to conceive in the first place.  Given that even the youngest of Young Earth Creationists believe that humanity is around 300 generations old, that's plenty of time for natural/artificial selection and/or animal husbandry to optimize this pretty key capability and to largely fix whatever genetic variants promote such throughout the population.  Compare, for instance, lactose tolerance, which took very little time to become near universal in populations where cattle were common.

Both of these problems point to the conclusion that we don't understand this portion of reality anywhere near as well as perhaps we think we do.  This isn't to say that we know nothing, or that what we know is not useful (look to the radically increased yields we've been able to squeeze out of plants, for instance, even before modern 'genetic engineering' or, for instance, the incredible amount of intellectual talent the first wave of psychometrics was able to mine out of unexpected sources).  But it does tend to indicate that we should try to avoid straying too far from the actual data. 


sconzey said...

I don't get why people think homosexuality is dysgenic. Homosexual men and women feel the same desire to procreate and propagate their genes that heterosexual men and women feel.

Ironically it's probably due to the increased tolerance of modernity that homosexuality will disappear. When gays and lesbians were unable to express their sexuality openly, their only opportunity to have children would have been to marry someone of the opposite sex, then grin and bear it. Today many homosexuals who want kids adopt, rather than selecting the more expensive surrogacy/IVF.

red said...

"On the other side, we have women like two of my sisters in law who have had a great deal of such difficulty, one of whom would not survive a pre-modern childbirth. Similar differences exist in terms of ability to conceive in the first place. "

Human child birth is quite bad due to the size of our brains. But if you optimize it by making the heads proportionally smaller you end up with dumb kids and they die off everywhere but Africa.

The other issue is that the human race has been under unnatural selection outside of Africa for some 50,000 years or so. Warfare, dealing with harsh climates and limited resources has been the order of the for a long time. Add in civilization and our killing off all natural predators in most places to that mix and you have a lot non natural forces doing the selecting which does not necessarily optimize towards lots of births.

And optimizing for high rates of birth still goes on in some populations: Africans. Natural mortality is so high in Africa that Africans pop out kids like crazy and have low parental involvement in them. That's an optimized strategy in area where natural selection is still taking place.

spandrell said...

It is true that Darwinism doesn't currently answer those questions, but Creationism just forbids asking. Using God in biology is cheating, it disincentives further research. At least evolution keeps us asking questions.

And well I'm no biologist but there surely must be some drawbacks to fertility. Human reproduction is a very inefficient process. As are many organisms', not wall living species are as fecund as rabbits.
Again nature surely knows about Malthusian limits, so low fertility is not necessarily bad for fitness in the long term. Australian aborigenes used to eat their spare children, right?

I guess the overall leanness of a species depends on the harshness of selection pressure against them. Most species barely make ends meat, succumbing all too easy to disease, cubs get eaten all too easily, etc. Yet we are all here. Call it natural balance.

Leonard said...

red, all those things you mention are still natural selection. Even birth control is natural selection in action. Darwinian theory is almost tautological in this sense: whatever is, selects. The next generation has always been selected by definition, by whatever environment exists in this generation.

In the future, assuming current trends continue I expect homosexuality will decline somewhat in frequency because it is highly disgenic. (Scozney points out that its disgenic quality is subject to technology, which is true. But before artificial wombs become cheap, homosexual fertility will remain much lower than hetero fertility.)

Another thing we can expect is for people to evolve the desire for children, not just sex. Until recently, the two were equivalent, but now via tech they are quite distinct.

Jehu said...

Dysgenic is something of a loaded word. What homosexuality does do is lower TFR, moreso in an uncloseted society. How much desire you have to reproduce doesn't matter in animal husbandry or natural selection unless you actually go and do it. Presently, homosexuals don't and will probably not do so in ratios comparable to heterosexuals unless artificial wombs become cheap, as another commenter mentioned.
All of the examples I've given you are producing children with fairly high IQ levels...from +1 to +4 sigmas, and they're all Caucasians. So appeals to head size trading off birth survivability vs IQ don't seem to apply here---obviously the women of my family seem to have perfected the genetic 'technology' to give birth safely without need for C-section or any such intervention to children with large heads. So why is it that such women haven't become the overwhelming norm?
I'm not sure which creationists you hang with, but most of the ones I'm familiar with historically or presently who do science or thought at a high level don't view 'God did it' as a stop sign. Those with an engineering bent look to what they see as His handiwork as among the best possible places to steal ideas. For instance, I know a few young earth creationists who are actually optimistic about SENS (extreme longevity) efforts because of clues and elements in the Old Testament. Most of the greatest scientists in history have been creationists of one stripe or another, so apparently it can't hurt inquiry that badly :-)

Jehu said...

I am confident that you're quite correct about humans presently being selected for resistance to birth control (i.e., evolving the desire for children distinct from the desire for sex in your language). All of the Darwinian sweepstakes winners (e.g. the Duggars or the guy whose sperm has apparently been used over 150 times as a donor) seem to have it .