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October 05, 2003

Science ~ evil?

The Loom has a post up titled Fear of a Eugencist Planet that reviews a review of a book called War Against the Weak. He comes to the conclusion that the book is much ado about nothing (ie; biotech companies are not pawns of the new eugenicists).

He also brings up the point that it might be difficult to genetically modify intelligence: "If you wanted to make your kid significantly smarter, you'd have to tinker with a huge number of them [genes], perhaps hundreds or thousands." Well, what little I know does indicate that the affect of any given gene on intelligence might be small (predicated on the individual being within the normal range), perhaps on the order of 1%, but that's far from "thousands." Additionally, some psychologists have done research which indicates that heritability of IQ (variation within a population caused by genotype) increases as you move up the socioeconomic ladder, in other words, given a minimum quality of life the difference due to genetic inheritance looms larger[1]. I point this out because the post focuses on the possibilities of the rich using GE to boost the intelligence of their children. Carl Zimmer, spinmeister of The Loom, sounds a lot like our old pal Charles Murtaugh, throwing cold water on the prophets of the future. But I think sometimes he is limited by conventional preconceptions. He notes that "For a new species to incubate, it needs barriers around it to keep genes from the old species from flowing in and its new genes from flowing out"-well, yes, but those barriers can be social, if some religious nutsos decided to create biphallic sons, there would be issues with these sons being able to get mates from the mono-phallic majority. Additionally, GE would by its very nature alter the ground rules for speciation as mutation in the context of genetic drift and natural selection plus physical barriers thrown up by geography, etc. might not be the only sources of reassortment & segregation of genes within a population....

Update: Carl Zimmer responds to my response. And Greg Cochran swoops down upon the helpless message board....

fn1. See Behavorial Genetics in the Postgenomic Era.

Posted by razib at 03:20 PM

"you'd have to tinker with a huge number of them [genes], perhaps hundreds or thousands."


Gregory Cochran

Posted by: gcochran at October 5, 2003 05:45 PM

Thanks very much for your comments on my post. As a novice with trackback, I'm posting my thoughts on my own site. I'll get the hang of this back and forth soon, I hope.--Carl

Posted by: Carl Zimmer at October 5, 2003 05:56 PM

"You'd have to get tens of thousands of people to have sex only with one another for centuries. Good luck."

It's been done. Is everybody a straight man?

Posted by: gcochran at October 5, 2003 08:58 PM

Just because a multitude of genes affect intelligence, why would it follow that I need to modify more than one to achieve a significant effect? I mean, if that's some sort of official party line to soothe public fears of genetically engineered genius children, great. I'm sure it will go over well - 'intelligence, very complicated matter. No need to worry about drastic changes...'. But the evolutionary record strongly suggest that our intelligence has been checked until very recently by relatively banal constraints on nutrition, available calories, and length of infant development. This would imply that increasing intelligence may not be that difficult.

Posted by: bbartlog at October 6, 2003 07:21 AM

to bbartlog: Right. If the constraints ease, if you get some elbow room in the trade space, there's often nothing blocking major improvement in a quantitative trait.
And in some cases there will be strong single-gene effects. Teosinte -> maizze seems to have been caused, in the main, by changes in just a few genes of strong effect.

Posted by: gcochran at October 6, 2003 09:30 AM