Yet Another Gene for Intelligence

Obviously, I have to work this both into tonight’s talk in Grand Rapids, and blog about it:

Gene governs IQ boost from breastfeeding from PhysOrg.com
The known association between breast feeding and slightly higher IQ in children has been shown to relate to a particular gene in the babies, according to a report this week in the Proceedings of the National Academy of Sciences.

[]

But for now, I’ll just say this…

By way of cautionary notes. It is being said that this is evidence of intelligence being the result of “nature and nurture” interacting. This is because there is a gene that determines higher IQ, but only if the baby is breast fed.

Let me ask you a question. If a mouse or a monkey eats a piece of food and thusly obtains an important nutrient, is that nature or nurture? What if the same animal synthesizes the same nutrient … is that nature or nurture? What if an animal has a system of sometimes ingesting a particular nutrient, and other times, it ingests it? Is that nature or nurture?

Now, what about the individual in this theoretical species who has a gene that does a number of different things, including coding for an enzyme that is important in synthesizing this nutrient … BUT … it has a mutation in both copies of this gene such that it can’t synthesize the nutrient.

If you thought that eating the food to get the nutrient was “nurture” and synthesizing it was “nature” then you now have to believe that this mutant individual, and all it’s similar mutant con specifics, are more into “nurture” than “nature.” Indeed they are heading for being “unnatural” in a way, aren’t they?

Now think about breastfeeding in this context. Is this really a valid, interesting and properly formulated construct: That human babies who do not breast feed vs those that do are a testing ground for nature vs. nurture? In “nature” human babies that do not breastfeed starve to death. Think about it. It is an utterly silly question.

Now, go back to the synthesizing nutrient again for a moment. Imagine an animal that consumes and cannot synthesize all of the nutrients on a list of 10 items. It has an ancestor that synthesized one of these. And father back, an ancestor that synthesized 2 of them, and so on, going all the way back to a primordial form that synthesized all the nutrients.

This is an evolutionary scenario that may be a common pattern. Loss of ability to synthesize, compensated with the practice of ingestion, is more likely to happen that than rise of a novel way to synthesize something. Thus, there are in fact a lot of heterotorphs running around that synthesize a variety of nutrients. Non-heterotrophs tend to not end up with these novelties, they tend to synthesize nearly everything that they can and that their ancestors could.

So, we can think of this as a shift from “nature” to “nurture” if we stick with this nature-nurture logic. But then we have an interesting thing happening. Pretend for a moment that you believe in the nature-nurture dichotomy, and that you say to yourself, “Right, he’s got a point. There’s kind of a progression over historical and evolutionary time from nature to nurture. Humans are an extreme example of this, of course.”

Well, that would make you a ninny, for a number of reasons, but let me give you just one. The very first organism that constituted the ancestor of all the hypothetical organisms mentioned in the above paragraph was probably very close to a perfect heterotroph. The ability to synthesize nutrients probably evolved from that ancestral form, so over time, there were organisms that were more and more able to synthesize nutrients. This means that if you stick with the logic that I tricked you into believing (but no, I know you were not really fooled, were you?) then you now have to accept that life started out heavily involved with “nurture” … perhaps back in the days when cell membranes were the fanciest thing about a cell … and subsequently evolved to become more natural.

I will look into this latest IQ gene, of course. I’m predicting that, if the results are not spurious (and there is a reasonable chance of that) that this allelic difference relates to a number of effects and is essentially a “broken gene effect.”

The broken gene effect is like this, using an analogy for cars. You get a bunch of Fords and a bunch of Toyotas. Then you break some part … the same part in each case … of some of the Fords. Then you measure things about the cars, and determine that this thing you broke is the feature that makes Toyotas better than Fords. But all you really did is to look at something that is broken and draw a major conclusion about how life, the universe, and everything works. Maybe you should not have done that.

Another analogy, this time from sports: We can sometimes demonstrate that in a given year one football team does really badly because the players had too many injuries. So now, you get hired as the new coach for, say, the Vikings. The owners ask you what are you going to do to make the Vikings win at least one game a season. (A major improvement.) You say: “I’m going to unbreak any bones that are broken, and otherwise, uninjure everybody, because being uninjured is what makes you a great athlete.”

Clearly, injuries are an important determinant of how the season goes for the football teams. But if you want to understand what makes a team work, what makes the players good, and so on, you would really want to focus on other things. Like body size, strength, agility, etc. etc.

Otherwise you should not have this coaching job, I think.

Comments

  1. #1 Nathaniel
    November 6, 2007

    The whole nature vs. nurture thing is rather silly. Especially if “nurture” was developed “naturally”! Is not eating natural? but is being fed nurture? It’s just a bit confusing.

    What happens when formula developers find a way to engineer the proteins that trigger this IQ gene? That’s what I’m wondering. Super load it, see what happens.

  2. #2 greg laden
    November 7, 2007

    Nate: I hope you are on the way to the patent office right now!

Current ye@r *