An extended phenotype

| 37 Comments

Don Boudreaux on whether markets are an "extended phenotype."

Update:
More at Inclination to Criticize.

37 Comments

“They include things created by genes but that aren’t attached to bodies – for example, beaver dams and groundhog holes.”

Interesting.

Which “genes” have been found to govern instinctive behaviors?

What do you propose governs instinctive behaviour Dave? Jesus?

I don’t know what governs instinctive behavior and neither does Richard Dawkins.

That’s the whole point.

But Dawkins’ arguments are plausible and based on research.

Unless all of our instinctual behaviour was preprogrammed into us by our aemoba dubia overlords.

I’m a little skeptical of the idea of markets as extended phenotypes, at least if we assume that they are extensions of our genes. For most of human history, there were very few markets as we conceive them today. People lived in small hunter-gatherer tribes in which resources were mostly shared rather than distributed in market-like fashion. Certainly they bartered with other tribes, and to a certain extent within the tribe, but most of their economic activity would not have involved markets.

Markets seem to be one of those things that will arise spontaneously anytime you have limited resources and rational actors who cooperate to maximize their own well-being. To that extent, they aren’t an adaptation so much as simple fact of life. In theory, any organism could probably create a market given the proper circumstances.

Boudreaux: ”… as Dawkins puts it in his just-released The Ancestor’s Tale, “A ‘phenotype’ is that which is influenced by genes.”

Given the fameous maxim about butterflies in Brazil causing tornadoes in Texas, I’m looking forward to Dawkins claiming that weather is an extended phenotype.

Or, to put it another way: Everything “influences” something else. Using a vague a term as that is sure to generate some meaningless concepts. Problem is, the whole “genotype” vs. “phenotype” terminology is a relic of the view of genes as “master programmers” that Dawkins is still a proponent of.

I think I’m with Krauze. What difference does it make if they are or they aren’t? Does Boudreaux’s claim have any effect on our understanding of markets?

Does Dawkins have any other point in discussing extended phenotypes other than his desire to have genes be the sole answer to life, the universe, and everything?

My reading of Dawkins is that he is limiting his “extended phenotype” to reliable, immediate behavior of an organism. For example, is a bird’s call an example of its extended phenotype? The call is physically just moving air, not part of the bird. Yet birds are positively identified by their calls (and by their nests as well). Indeed, these things, not part of the bird’s body itself, are accurate identification right down to the level of regional variations. Any competent naturalist (or hunter) can identify many species by such indications. I don’t have any problem considering the bird’s call or nest to be an extended “part” of the bird, but I admit it’s necessary to draw the line fairly close. Otherwise, as Krauze notes, everything influences everything. I wouldn’t be comfortable regarding a crop as the “extended phenotype” of earthworms, however essential a role they may play in conditioning the soil.

Davescot -

I usually just lurk, but your comments floored me.

Even if you believe that the earth was created on Octber 25, 4004 BCE, instinctive behavior is still obviously genetic in origin. Or do you seriously suggest that God personally commands each of us to be aware when it’s time to urinate, and genetics has nothing to do with it? You’ll apparently literally say anything to argue with a scientist whose name is on your “bad guy” list, no matter how outrageous.

(Many instinctive behaviors are modified by learning in some species of course, especially humans.

I think my comments above came out a little harsh.

I’m not aware of specific genes that govern specific behaviors being isolated. It would be most unsurprising to me if that type of work is being done with Drosophila, but a quick check didn’t reveal a lot. One of the problems is that research into genetics and behavior invariably arouses a firestorm of controversy when ideas are extended to human social behavior.

However, a good practical example of the role of genetics in driving complex innate behaviors is dog breeds. Dogs descend from a common ancestor and are maintained as different breeds by human genetic manipulation (selective breeding); most breeds emerged in historical times - this is true even in a creationist model. Some breeds have strong special innate behaviors that don’t need to be taught - most retrievers “retrieve”, for example. They don’t have to be trained to do it (you can train them to make them even better at it, or modify it, but they do it “naturally”). Dogs have an extremely high capacity for learning, but the genetically determined innate behaviors, abilities and “personality” of the breed will nearly always be evident.

Hi Harold,

YECs aren’t the only ones saying that genes alone are insufficient for determining the organism. Here’s Brian Goodwin, a British developmental biologist:

“The proposition that “the collection of chromosomes in the fertilized egg constitutes the complete set of instructions for determinng the timing and details of the formation of the heart, the central nerveous system, the immune system, and every other organ and tissue required for life” (C. Delisi, 1988) is incorrect. These instructions, which define a genetic program, can determine the molecular composition of a developing organism at any moment in its development, but they are insufficient to explain the process that lead to a heart, a nerveous system, a limb, or any other organ of the body. … So the morphology of organisms cannot be explained by the action of their genes.” B. Goodwin, How the Leopard Changed Its Spots: The Evolution of Complexity (Princeton, 1994), pp. 34-5, my emphasis in bold.

Krauze:

These instructions, which define a genetic program, can determine the molecular composition of a developing organism at any moment in its development, but they are insufficient to explain the process that lead to a heart, a nerveous system, a limb, or any other organ of the body

I wasn’t aware that the state of the art had reached the point where such a statement could be made, but of course I’m not a biologist. Where does Goodwin think the information necessary to form a heart ultimately comes from? I’ve read of experimenters moving genes around somehow and causing eyes to grow on legs or on antennae. Does this not imply that eye formation is controlled in some manner by such genes? Perhaps these genes only tell the developing organism where to put an eye, but not how to make an eye (because the same gene causes eyes of the appropriate type for the organism). But this still begs the question of where eye-making instructions come from.

What IS the morphology of organisms explained by?

Hi Harold,

A response to your second post and an elaboration of my own. Just because some behavior is innate doesn’t mean that it’s wholly determined by genes. Organisms recieve more than DNA from their parents - in addition to that one-dimensional string of nucleotides, they also receive the three-dimensional structure that is the cytoplasm, and where protein synthesis takes place. There’s a lot of information in that structure.

Hi Flint,

“I’ve read of experimenters moving genes around somehow and causing eyes to grow on legs or on antennae.”

A minor nitpick: The work you talk about resulted in structures growin in each other’s place, not on each other. Besides, I think it was the other way around - legs or antennae growing in the place of eyes.

“Does this not imply that eye formation is controlled in some manner by such genes?”

Sure, eye formation is in some manner genetically controlled. However, this is a far cry from elevating genes to “master programmers” and trying to reduce all of evolution to them. As you yourself say, hox genes most likely act as markers only - traffic lights guiding the flow of traffic.

With the rise of developmental biology, morphogenesis has resurfaced as a problem in biology - check out Origination of Organismal Form: Beyond the Gene in Developmental and Evolutionary Biology (MIT Press, 2003), edited by Müller & Newman, for a recent discussion.

I think we need to look at that 99% of non-genetic material that’s passed on from parent to offspring. It’s long been known that DNA inserted into the egg from a different species won’t result in a viable organism (for an example, just watch “Jurassic Park”, on the importance of getting eggs from species that were similar to dinosaurs). Rather than being a passive “interpreter” of the genome, the view is shifting towards the egg being seen as an active participant in morphogenesis.

When most biologists say that genes alone don’t determine morphology or behavior or whatever, what they usually mean is that there is no simple mapping from one gene to one trait for each and every trait. Instead, there’s a complex interplay between genes and environment, and in many cases what the genes do is very indirect. So you can not determine the outcome based on genes alone, you need knowledge of other factors. But in no case do biologists (at least, not mainstream biologists) argue that genes are not of utmost importance.

By the way Krauze, can you share with us the part that was cut out via ellipsis in that Brian Goodwin quote? I suspect that there is some important elaboration in there.

Hi Krauze -

I thoroughly agree. I didn’t mean to imply that “only” genes were required for development, and that the cytoplasmic environment of the fertilized ovum had nothing to do with it. That position would seem seem to be easily dismissed. Obviously, golden retrievers come from golden retriever zygotes, not naked golden retriever DNA. We could get a bit circular and say, “but what determines the cytoplasm/organelle/membrane environment of the ovum a female golden retriever produces?”. But your point is well taken.

Nevertheless, genes - sequences of DNA - do have a vast amount to do with how an organism develops and what the final product will be. Changing of genes is well known to account for changes we see in drosophila, peas, insecticide-resistant insect pests, antibiotic-resistant bacteria, mice that are especially good “marathon” runners, mice/cattle/cats that develop hypertrophied skeletal muscle, “genetically modified” tomatoes, and humans who suffer from a whole range of developmental or metabolic disorders, just off the top of my head. Note that, despite the last item, I’ve included some ‘positive mutations’ in the list ;). The list is also mainly things related to single gene changes.

We’re at a different level of discussion here, though. The person I initially addressed seemed to be dismissing the idea that genes even contribute to innate behaviors. That’s just silly. The genome isn’t a crude “blueprint”, but it is, well, the genome - the major source of inherited information. Information that can’t be expressed except in the appropriate complex environment, admittedly.

I’m not a big fan of Richard Dawkins - he has a style (as have many great scientists over the years, admittedly) of trying to make his ideas sound extreme or shocking in order to draw attention to himself, and also of exaggerating trivial differences with other scientists. But I was just floored that someone - even a staunch creationist - would argue that innate behaviors have nothing to do with genes.

Dawkin’s notion of extended phenotypes can be debated, but Boudreaux’s application to markets is ignorant ideologically motivated claptrap and I’m surprised to see such garbage promoted here. Dams, hives, webs, anthills, nests, and so on have all evolved; they (through the organism’s capacity to produce them) are expressed by genes, their features are subject to natural selection, and their variation across species is observable. Nothing of the sort applies to markets. The view of free markets as a natural feature has even less evidentiary support than the design argument, but is similarly supported by self interest and sophistry.

Are markets an extended phenotype of humans? A case can be made that they are.

Then why isn’t one offered?

We are programmed to trade, to exchange, to seek bargains, all in order to make ourselves better off and, hence, to promote our survival. Markets certainly do promote our survival.

Aside from the dubiousmess of the claims, this is not an argument that markets are an extended phenotype. In fact, it displays a very poor grasp of the meaning of “survival” and its role in evolution – the sort of poor grasp common among Social Darwinists, which these free market dogmatists certainly are. “promote our survival” – whose survival? homo sapiens? What the heck does that have to do with allele frequency? This fellow says Dawkins is his favorite author, but I have to wonder about his ability to comprehend and absorb what Dawkins writes, beyond some conceptual cherry picking to shore up his dismal ideology.

YECs aren’t the only ones saying that genes alone are insufficient for determining the organism. Here’s Brian Goodwin, a British developmental biologist:

Hey, there’s one critic of the consensus view, and there are others, but arguments from authority aren’t valid. Perhaps you could explain why we should credit Goodwin’s view. His argument is against “Darwinism” because it doesn’t explain mophological development, but he might as well argue against Quantum Mechanics on the same basis.

These instructions, which define a genetic program, can determine the molecular composition of a developing organism at any moment in its development, but they are insufficient to explain the process that lead to a heart, a nerveous system, a limb, or any other organ of the body.

Note the switch from “determine” to “explain”. (Did you? If not, you should consider taking some courses in critical thinking and analysis.) This looks like argumentum ad ignorantiam coupled to a category mistake. Current genetic theory may provide insufficient explanation, but chromosomes aren’t in the business of providing explanations.

This seems to some degree as a case of marketing with scientific terminology. I am sure many of you can remember how a lot of concepts (some sensible some ssensationalist nonsense) have been labeled with ‘quantum’, ‘chaos’, ‘non-linear’ or ‘non-deterministic’ over the last decades whether the shoe fit or not. Similar has been the reflex to call everything from abiogenesis to strange political ideologies ‘evolution’ after Darwin’s success. So this might just be a strange way to either honour Dawkins, claim his authority for another idea or just capitalize on the name recognition.

This is both poor economics and poor biology. Tim has a habit of exapting Panda’s Thumb to promote his right wing causes. This leaves Panda’s Thumb unbalanced. There is nobody to counter what he does-save for me when I occasionally show up to debunk Tim.

Firstly, the author of this post misuses “extended phenotype”. Whatever else you can say about Dawkins, Dawkins never claimed that human reasoning and behavior was genetically programmed the way a beaver’s dam is genetically programmed. In fact, Dawkins has always been careful to confine Sociobiological explanations to reproduction, kin selection and adaptation. Though the concept “meme” is probably flawed (IMO) Dawkins use of it shows that Dawkins recognized a distinction between a gene and a meme. And of course Dawkins was careful to emphasize that “selfish genes” did not automatically create “selfish people”.

It has been characteristic of the opponents of Sociobiology to accuse Sociobiologists, including Dawkins, of arguing that we are slaves to our genes (genetic determinism) and of course Sociobiologists have always argued back that they have never said we are slaves to our genes. Now along comes someone to exapt Sociobiology and use it to claim that we are in fact, slaves to our genes.

Secondly, this is a poor use of Hayek. Hayek never made the claim that markets were “natural” or a consequence of biology. Hayek argued that through trial and error and the use of something between “reason” and “instinct” we had stumbled on to a successful cultural adaptation-the market. Hayek does make the claim that altruism is easier and more likely with close associates, but he never made the claim that genes made markets. He was much too subtle and advanced a thinker for that. Hayek viewed markets as an example of extra-genetic transmission of information.

So for starters, this is wrong on two counts. It is misuse of Dawkins and misuse of Hayek. It is not even a beneficial exaptation.

Yeah. I’m such an cracked ideological fanatic that I promote my right wing causes by…um, just linking to an interesting post. The horror!

http://www.sscnet.ucla.edu/anthro/faculty/boyd/

Anybody interested in seeing an example of serious scholarship that attempts to grapple with the difficult and extremely complex issues of the relationship between genes and human behavior could start at this link. It’s only one example and I wouldn’t even endorse it all-though I would endorse the scholarship behind it.

If you want to see an example of someone who has taken the time to seriously think through the relationship of Neo-Darwinism to economic theory, try doing an Amazon search on Geoff Hodgson.

Hi Steve,

“But in no case do biologists (at least, not mainstream biologists) argue that genes are not of utmost importance.”

No, and I would hope as much. Obviously, a cell without DNA isn’t going to produce anything worthwhile. And the same goes for DNA without a cell.

“By the way Krauze, can you share with us the part that was cut out via ellipsis in that Brian Goodwin quote? I suspect that there is some important elaboration in there.”

No problem. Here’s the entire paragraph:

The proposition that “the collection of chromosomes in the fertilized egg constitutes the complete set of instructions for determinng the timing and details of the formation of the heart, the central nerveous system, the immune system, and every other organ and tissue required for life” (C. Delisi, 1988) is incorrect. These instructions, which define a genetic program, can determine the molecular composition of a developing organism at any moment in its development, but they are insufficient to explain the process that lead to a heart, a nerveous system, a limb, or any other organ of the body. The reason is, as we saw in chapter 1, that knowing the molecular composition is not, in general, sufficient to determine its form. This follows from basic physics. We also need to know the principles of organization that are involved in the system to explain what forms it can take. Then we can understand how such factors such as molecular composition influence the development of a particular form. So the morphology of organisms cannot be explained by the action of their genes. One of the leopard’s distinctive spots fades away.

Tim writes:

“Yeah. I’m such an cracked ideological fanatic that I promote my right wing causes by…um, just linking to an interesting post. The horror!”

I thought the post was uninteresting. I thought it was an unwiting self caricature of socio-biology and of Austrian economics.

There is an immense amount of interesting work on the evolution of human sociality and cooperation. There is an incredible amount of fascinating work on the evolution of market economies. There is so much good, nay excellent scholarship being done. You could have linked to that.

It’s between you and the owners of Panda’s Thumb to determine what gets posted on here. I’m just the peanut gallery offering my comments.

My comment is this was uninteresting, crude, crass, vulgar genetic determinism that has been roundly rejected by every serious scholar working in sociobiology and Ev Psych and not at all in keeping with the Hayekian tradition.

I think it has the status of junk science.

So the morphology of organisms cannot be explained by the action of their genes.

For some reason, this statement continues to bother me. I wouldn’t mind someone saying “we haven’t yet established in detail all of the factors that determine morphology.” From what I have read, we remain a long way short of being able to do so. That is, we simply do not know the explanation. And not knowing, how can anyone say “It’s not the genes”? At best, Goodwin can make the point that IF the genes are responsible for the processes that lead to hearts etc., we don’t see how.

Goodwin himself is in the minority, but I may (I’m not sure) agree with Krauze that if the majority is assuming the genes contain all of the necessary instructions (even if encoded in ways we are far from ferreting out), they should make this assumption explicit.

Back to the original post, I doubt Dawkins would consider much if any side-effects of human behavior to be extended phenotypes. People are somewhat more flexible than Dawkins’ notion encompasses.

Hi Harold,

“We could get a bit circular and say, “but what determines the cytoplasm/organelle/membrane environment of the ovum a female golden retriever produces?”.”

Good question. I wish I knew the answer. One possibility: When you separate the stalk of the one-celled algae Acetabularia from the nucleus-containing base, it will generate a new cap (and sometimes a whorl), before dying from lack of nutrition. This would suggest that while the information for producing proteins and other building blocks resides in the DNA, the cytoplasm contains the information necessary for its own construction.

“The person I initially addressed seemed to be dismissing the idea that genes even contribute to innate behaviors.”

Then our interpretations differ. I read Dave as raising some sound skepticism over the claim that genes “create” beaver dams and groundhog holes. Sure, genes contribute to instinctive behavior - at the very least, to exhibit behavior, one needs a functioning brain (well, except for those stupid IDists, right? ;-) ). And to have a functioning brain, one needs electron transporters, and they certainly are coded for by genes. But to jump from that and claim that beaver dams are created by genes, seems to me to involve playing fast and loose with the term “create”.

Anyway, I’m not interested in fighting the battles of others. If Dave really meant that genes make no contribution to morphology what-so-ever, that’ll be his headache. My interest in entering this discussion was Dawkins’ “extended phenotype” meme and the genocentrism that underlies it. If organisms can only be understood as interactions between their genes and their cytoplasm, then why denote one as the active “genotype” and the other as the passive “phenotype”? What about the “cytotype”?

Hi TS,

“Hey, there’s one critic of the consensus view, and there are others, but arguments from authority aren’t valid.”

Hey, easy now. We’re all friends around here, right? Instead of assuming that because I spend ten minutes of my time to post a quote, I must be making an argument from authority, just ask me nicely if I’d like to elaborate, okay?

So, Goodwin is just “one critic of the consensus view”? Here’s a question for you, TS: What is the consensus view on the causes of morphogenesis, and what evidence supports it? And remember, no arguments from authority.

“His argument is against “Darwinism” because it doesn’t explain mophological development, but he might as well argue against Quantum Mechanics on the same basis.”

You must be knowing something I don’t. Could you please cite where Goodwin makes the argument you’re attributing to him?

Goodwin: “These instructions, which define a genetic program, can determine the molecular composition of a developing organism at any moment in its development, but they are insufficient to explain the process that lead to a heart, a nerveous system, a limb, or any other organ of the body.”

TS: “Note the switch from “determine” to “explain”. (Did you? If not, you should consider taking some courses in critical thinking and analysis.) This looks like argumentum ad ignorantiam coupled to a category mistake. Current genetic theory may provide insufficient explanation, but chromosomes aren’t in the business of providing explanations.”

Is this just a nitpick, or is a real argument lurking in there? Terminology to the effect that “genes explain” something is quite common among researchers.

Krauze, the Acetabularia example you mention speaks, not to some sort of ill-defined information inherent in the cytoplasm and independent of the nucleus, but rather of the use of stored mRNAs in growth and development in these organisms. That the stalk eventually stops “regenerating” reflects a diminution of “stuff” provided by the now-gone nucleus, not a cessation of nutrition.

This is an important mechanism by which the nucleus “speaks” to later generations.

Hi Art,

Thanks, I was unaware of this. You don’t happen to have a reference for that?

Krauze et al -

I think we can all agree that genes, sequences of DNA, are necessary but not sufficient for development, and thus for the expression of innate behaviors by the fully developed organism.

To stick with a sexually reproducing, mammalian example, the zygote we begin as gets a great deal more than just DNA from the maternal ovum, but only a very little bit more than DNA from the sperm. Yet our father’s genetic traits are crucial determinants of our final, with apologies to those who dislike the term, phenotypes.

Throughout development, DNA finds the “right” environment for itself, and also contributes to processes that create the next stage of development, which is in turn, part of the environment in which newly replicated genes find themselves, and so on.

Incidentally, bacterial behavior can be directly related to individual proteins, and thus to individual genes. This is coming back to me from courses taken many years ago, but…some motile bacteria will change direction if they encounter an obstacle. The mechanism is related to pressure sensing proteins, which either are or are linked to ion channels. “Bumping” into a “wall” thus causes changes ion concentration in a local area of the bacterial cell. This in turn affects other proteins, such as cytoskeleton proteins (yes, bacteria have a cytoskeleton), resulting in a change of direction.

Yeah. I?m such an cracked ideological fanatic that I promote my right wing causes by?um, just linking to an interesting post.

Exactly so. You seem to think people are stupid.

Krauze,

For now, the introduction of the article by Vogel et al. (Differential Messenger RNA Gradients in the Unicellular Alga Acetabularia acetabulum. Role of the Cytoskeleton, Plant Physiology 129, 1407-1416, 2002) has a pretty fair overview of this phenomenon, and the mechanisms I refer to. The more general field of stored mRNAs and their roles during development has a large and interesting literature.

“Hey, there’s one critic of the consensus view, and there are others, but arguments from authority aren’t valid.”

Hey, easy now. We’re all friends around here, right? Instead of assuming that because I spend ten minutes of my time to post a quote, I must be making an argument from authority, just ask me nicely if I’d like to elaborate, okay?

Eh? It is an argument from authority: “even this here developmental biologist thinks so” – I didn’t “assume” it to be one. I have no idea why an ad hominem consideration like the amount of time you spent would be relevant. And I’m not about to ask the authors of posts to elaborate on them before I comment on them. If you wish to elaborate after I comment, that’s up to you.

So, Goodwin is just “one critic of the consensus view”? Here’s a question for you, TS: What is the consensus view on the causes of morphogenesis, and what evidence supports it? And remember, no arguments from authority.

Your request is only relevant to an argument from ignorance, as I already noted. The causes of morphogenesis and the supporting evidence aren’t relevant to the question of whether “genes alone are insufficient for determining the organism”, any more than the evidence supporting flagellagenesis is relevant to the question of whether evolution is insufficient for producing flagella. You introduced Goodwin’s statement to support the claim that genes aren’t sufficient to explain morphogenesis – the burden is on you and him to show that, and the given quote doesn’t do so.

“His argument is against “Darwinism” because it doesn’t explain mophological development, but he might as well argue against Quantum Mechanics on the same basis.”

You must be knowing something I don’t. Could you please cite where Goodwin makes the argument you’re attributing to him?

Since you’re the one who quoted him, one might expect you to know something about him. See, for instance. http://home.wxs.nl/~gkorthof/kortho23.htm

Goodwin: “These instructions, which define a genetic program, can determine the molecular composition of a developing organism at any moment in its development, but they are insufficient to explain the process that lead to a heart, a nerveous system, a limb, or any other organ of the body.”

TS: “Note the switch from “determine” to “explain”. (Did you? If not, you should consider taking some courses in critical thinking and analysis.) This looks like argumentum ad ignorantiam coupled to a category mistake. Current genetic theory may provide insufficient explanation, but chromosomes aren’t in the business of providing explanations.”

Is this just a nitpick, or is a real argument lurking in there? Terminology to the effect that “genes explain” something is quite common among researchers.

The argument I made is plain as day.

Imagine an alien race studying our computer technology. One of them says “these instructions, which define a program for the computer, can determine the state of the computer at any point in time, but they are insufficient to explain the process by which the computer solves problems”. That’s nonsense – the instructions determine not just the state of the computer at any point in time, but the progression of its states through time. What the aliens, not the instructions, lack is an adequate algorithmic theory to explain that progression. That lack does not in any way imply that computer instructions “alone are insufficient for determining” computer processes – which is analogous to the position that you introduced Goodwin to support.

Goodwin himself is in the minority, but I may (I’m not sure) agree with Krauze that if the majority is assuming the genes contain all of the necessary instructions (even if encoded in ways we are far from ferreting out), they should make this assumption explicit.

But note that Goodwin himself,as quoted by Krauze, says “These instructions, which define a genetic program, can determine the molecular composition of a developing organism at any moment in its development”

So Goodwin is no support for Krauze if Krauze’s point is that not all the information is in the genes. Indeed, not all the information to develop an organism is in the genes – for instance, the range of ambient temperatures on Earth is not encoded in the genes, yet is essential for development, and there’s a huge amount of other necessary information in the environment, such as the molecular composition of the egg yolk. In fact, it’s because not all the information is in the genes that natural selection occurs.

Goodwin’s point is different – that the theory of evolution is not a theory of morphogenesis. All I can say to that is – duh. As I noted, physical theory is also not a theory of morphogenesis, but that’s no strike against physical theory.

If organisms can only be understood as interactions between their genes and their cytoplasm, then why denote one as the active “genotype” and the other as the passive “phenotype”? What about the “cytotype”?

For the same reason that we say that cookbooks, not flour and sugar, contain cake recipes.

The proposition that “the collection of chromosomes in the fertilized egg constitutes the complete set of instructions for determinng the timing and details of the formation of the heart, the central nerveous system, the immune system, and every other organ and tissue required for life” C. Delisi, 1988) is incorrect. These instructions, which define a genetic program, can determine the molecular composition of a developing organism at any moment in its development, but they are insufficient to explain the process that lead to a heart, a nerveous system, a limb, or any other organ of the body. The reason is, as we saw in chapter 1, that knowing the molecular composition is not, in general, sufficient to determine its form. This follows from basic physics. We also need to know the principles of organization that are involved in the system to explain what forms it can take. Then we can understand how such factors such as molecular composition influence the development of a particular form. So the morphology of organisms cannot be explained by the action of their genes. One of the leopard’s distinctive spots fades away.

Wow, it’s weird that you would have quoted Goodwin with his reasoning removed.

This full quote further illustrates the sort of conceptual confusion – a category mistake – that I noted. Goodwin confuses lack of knowledge – of “principles of organization” – and understanding – of “how such factors such as molecular composition influence the development of a particular form” – with what is potentially explainable by the actions of genes. Once we understand morphogenesis better, it might be clearer how the actions of the genes accounts for the observed results.

Goodwin’s claim is akin to saying that a recipe for bread determines the molecular composition of the bread but not the development of its shape over time. But the difference between a recipe that calls for yeast and one that doesn’t isn’t simply a difference between bread containing yeast and bread not containing yeast. The resulting rising of the bread is determined by the recipe, given the properties of yeast, ovens, and so on. Those properties are not part of the recipe, but are implicit in why we follow that recipe and not another. Likewise, the properties of organic molecules are not to be found in the genetic information, but are implicit in why those genes and not others were naturally selected. Genes, together with the physical properties of organic compounds, determine the forms that organisms take – or rather that is plausible, and Goodwin has offered no reason to think otherwise.

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This page contains a single entry by Timothy Sandefur published on February 14, 2005 9:08 AM.

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