A Bit More Detail

Assorted Personal Notations, Essays, and Other Jottings

[LINK] “Why Eugenics Will Always Fail”

Esther Inglis-Arkell’s io9 essay on some of the problems likely to face any large-scale human eugenics program is worth reading. The central argument, that we just don’t know enough about our genetic inheritance to hack it about, is one that will give way over time, but that will remain an important factor nonetheless.

Selective eugenics cannot do otherwise but have an effect. Obsessively manage a familial line over generations, and it will change a species. However, every species will respond differently. Assuming that eugenics will have as much of an effect on humans as it does on other species is wrong. Assuming it will have the same effect it does on the more genetically pliable species can be fatal.

Even the success that we see with dogs comes at a price. Though different breeds of dogs might have a trait that’s desirable to humans, they aren’t more fit to survive than their wild compatriots. And what becomes of all their selective breeding? Aside from any number of diseases, weaknesses, and health problems endemic to dog breeds, they lose biodiversity. It’s estimated that five percent of wolves’ diversity was lost when they became domesticated dogs. When those domestic dogs were obsessively bred to make, say, a golden retriever, they lost another thirty-five percent of their diversity.

Humans don’t have that much biodiversity to lose. Grab any two humans on Earth and they’re likely to be more similar to each other, at the genetic level, than two chimps from the same tribe. It’s thought that the human race came close to extinction in the past, and that the few survivors became genetically close to each other. Losing another thirty-five percent of our diversity is not a tempting prospect. Going back to the dog model, scientists generally agree that their mutations don’t involve introduction of new genes, but expressions of ones already existing ones, which is why they can still interbreed so well. All that difference in genetics is what allowed them to change form in order to adapt to different conditions. Human eugenics isn’t going to be about trying to create many different breeds, but about going for an ideal. Limiting our biodiversity in the name of one ideal, or even a chosen few, doesn’t just change the human species in the present, it cuts off our capacity for change in the future. It’s widely acknowledged that a species that limits its gene pool leaves itself extremely vulnerable to any change from its ideal conditions. If the world itself changes — which is pretty much a guarantee — the human population could very well be stranded at a dead end.

So what would we gain for this vulnerability, and this expenditure of energy and care on selective human eugenics? What’s the ideal trait that we’d like for future humans to have? The general consensus on what we’d like to breed into the human population is intelligence. The human brain wants to preen and protect itself. This separates us from the animals! Except there’s no pure way, genetically, to do that. During a recent interview with Io9, Gary Karpen, a UC Berkeley biologist, has said flat-out that, given all possible genetic information about a child, it is in no way possible to predict intelligence. There are too many traits bound together, too many ways that genes might be expressed. The leader of the Human Genome Process, Francis Collins, said the same in his own book, claiming that no amount of genetic tinkering could give people designer babies with intelligence to order.

Well, what about other things? Strength? Fertility? Resilience? The problem is there is no one smart gene, or fertile gene, or strong gene. Mix the DNA of two geniuses and, even assuming somewhere in the soup of their DNA intelligence is passed down, it drags a net of other traits along with it. Those who manage animal breeding notice the same. When one can breed in a trait like swiftness in horses, or health and fertility in chickens, it generally comes with any number of other characteristics. Thoroughbreds and “hot-blooded” horses are notoriously temperamental. One study in poultry husbandry showed that even moderate increases in hen fertility and health came with increase in aggression, hysterical behavior, weird imprinting responses in the young, and odd sexual behavior. Good luck with that mixed in to the human population. Eugenics can’t be a scalpel. It’s a club. Even assuming we could get an extraordinary trait in one area, it would come with a whole host of other traits that wouldn’t be so desirable.

Written by Randy McDonald

July 23, 2012 at 7:37 pm

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