In my earlier blog commentary on Richard Dawkins, I described the function of the gene - replicating and transcribing. I abstained from giving any attribute to this self perpetuating gene other than describing as it is, replicating and transcribing, a rule set by Nature and a function that the simple agent, the gene, has to perform.
I was engaged in a healthy discussion with a fellow blogger, and lots of terms were thrown out about "selfish individuals", "game theory", etc. Since I approached the topic of genes from the eyes of a complexity theorist, I would like to take it further in that direction.
I would like to add that if an organism faces extinction, the genes that constitute it will face extinction and elimination. I would like to take the arguement one step further. However, I need an apt illustration. Consider the prey-predator simulation in a Java applet. The attributes of a prey, i.e. eyesight, speed, reproductive capacity, metabolic rates, etc can be set. The same goes for a predator. Intuitively, these attributes of the prey and predator can be decided by their genetic make-up, and they can pass down their attributes to their offspring. The attributes for the environment that provides the setting for the game between the prey and predator can also be set. Seasonal availability of food can be set at various time points and locations when the applet its running. The game will allow different species of preys and predators with different sets of attributes to compete. More advanced applets will be able to incooperate evolution of cooperative, selfish and altruistic behaviour amongst preys and predators along time points.
Users familiar with the applet will inevitably come into conclusion that the net survival of the prey or predator will depend on the interaction between the two and the environment. Preys with high metabolic rates will be able to move quickly, allowing it to evade capture, but it requires more food, and will least likely survive a drought. The same for a predator. Preys with lower metabolic rates will move less quickly and prone to capture, but they require less food and can survive the period of drought during the game. Population of preys and predators is also an important parameter. Depending on the set of attributes prior to the game, certain species of preys and predators face extinction at certain time points when the game is running.
The perpetuation of a species, and essentially their genes, thus lie in the outcome of their interaction within their own species and with other species and the environment. More advanced algorithms can allow decision-making for intra-species and inter-species behaviour. This is why from the standpoint of a complexity theorist, the ability for the organism to survive and for its genes to be passed on is the consequence of complex interactions, an interplay between the organism itself, other organisms and the environment. That is why I choose not to ascribe any attribute to the gene, other than describing it as it is in terms of its function. Whether it can perpetuate, is subjected to the outcome of interaction of the organism with others players and the environment, hence it's really a matter of COMPLEXITY. Rather than to simplify everything to the level of genes, I choose to adopt a macroscopic view.
Citation:
1) Rajesh R Parwani. Prey and predator system. http://staff.science.nus.edu.sg/~parwani/c1/node67.html
2) Java applet http://www.tu-dresden.de/fghhihb/petzoldt/models.html (Used to work in the past but not sure what happened. However, it's worth a try emailing the author at the University of Dresden.
3) Critical and oscillatory behaviour of a system of smart preys and predators, by A. Rozenfeld and E. Albano, Phys. Rev.
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7 comments:
Sorry, Socrates, but I still think you're completely misinterpreting Dawkins.
No sane biologist will deny that whether a gene can perpetuate depends on its interaction with its environment (which includes other individuals, other genes, chemical conditions, etc.). Dawkins would certainly not deny that. Natural selection necessarily involves interactions between the units of selection (genes) and the environment. It cannot operate otherwise.
The metaphor of the selfish gene was meant as a contrast with other theories where the individual was the unit of selection or where the group was the unit of selection (group selection).
Finally, the Royal Institute of Philosophy article I linked to in the comments of your other post makes clear that
1) Dawkins does not believe genes are selfish in any behavioural sense. Genes are not organisms, so they can not behave any more than furniture can behave.
2) The metaphorical selfishness of genes does not imply the selfishness of individuals. On the contrary, it implies, amongst others, kin selection, reciprocal altruism, and other mechanisms that favour altruistic behaviour. There is no link between selfish individuals and selfish genes. The selfish gene is a metaphor meant to make especially salient the point that selection occurs on genes and not on individuals or groups.
In other words, Dawkins has no quibble with your assertion that a gene is just doing its job. It sure is. It's doing its job as a unit of selection.
First and foremost, nowhere have I denied that the gene is the unit of evolutionary selection.
This was what Dawkins has clarified in the Royal Institute of Philosophy webpage:
"I shall return to this misunderstanding of me, but for the moment let me concentrate on her more serious misunderstanding of the definitional conventions of the whole science of ‘sociobiology’, a science of which she aspires to be a serious scholar.[2] When biologists talk about ‘selfishness or ‘altruism’ we are emphatically not talking about emotional nature, whether of human beings, other animals, or genes. We do not even mean the words in a metaphorical sense. We define altruism and selfishness in purely behaviouristic ways: ‘An entity… is said to be altruistic if it behaves in such a way as to increase another such entity’s welfare at the expense of its own."
"If I spoke of a ‘selfish elephant’ I would have to be very careful to state, over and over again, whether I meant the word in its subjective or its behaviouristic sense. This is because a good case might be made that elephants subjectively experience emotions akin to our own selfishness. No sensible case can be made that genes do, and I therefore might have thought myself safe from misunderstanding. To make doubly sure, I still went to the trouble of emphasizing that my definition was behaviouristic. The many laymen who have read my book seem to have had little trouble in grasping this simple matter of definition"
Dawkin's mentioned that his definition was behaviouristic.
Secondly, when I speak of genes as "selfish", I was talking of their persistence in passing down to subsequent generation. In the debates so far, I described the gene as doing its job, whilst not giving any attribute to the gene's persistence in passing down to subsequent generations.
I interpreted The Selfish Gene as what is described in the Wikipedia page. http://en.wikipedia.org/wiki/The_Selfish_Gene
"Describing genes with the term "selfish" is not meant to imply that they have actual motives or will – only that their effects can be accurately described as if they do. The contention is that the genes that get passed on are the ones whose consequences serve their own implicit interests, not necessarily those of the organism, much less any larger level."
Lastly, Dawkin has a view of organisms as mere vehicles for the persistence of the gene.
http://en.wikipedia.org/wiki/The_Selfish_Gene
"In a similar inversion, Dawkins describes biological organisms as "vehicles" or survival machines, with genes as the "replicators" that create these organisms as a means of acquiring resources and copying themselves. At the level of organisms, we can see genes as being for some feature that might benefit the organism, but at the level of genes, the sole implicit purpose is to benefit themselves."
I have also raised comments on Dawkin's view of organisms as a mere vehicle for the propagation of the gene.
There was also a rhetorical call to arms in the rebel against the design of the Selfish Gene.
http://www.simonyi.ox.ac.uk/dawkins/WorldOfDawkins-archive/Dawkins/Work/Books/selfish.shtml
I wrote in my most recent post that this battle has been raging since the beginning of evolutionary time.
I also came out with an illustration to show that genes can become extinct, deleted, under a few circumstances - 1) The organism makes a migration to an environment, which doesn't require the gene. With the encroachment of mutations, it will be deleted from the genepool. 2) A large number of genes performing the same function, more than what the organism actually require. Some will end up being deleted, and the organism will end up with what he needs.
I never did you think you denied that the gene is the unit of selection. I just don't think Dawkins would disagree with anything you've said so far. All his so-called 'behaviouristic' concept of selfishness is meant to demonstrate is that the gene is the ultimate unit of selection. It is not meant to demonstrate independence of environmental conditions, or genetic determinism, or whatever. All you seem to have said is that whether a gene is propagated depends on many interactions with the environment and whatnot. Dawkins would not disagree with any of that. As I said, natural selection necessarily involves interactions with the environment. You cannot be an evolutionary biologist without believing that.
I fail to see how competition amongst genes, leading to genes being eliminated, contradicts anything of what Dawkins says. The genes that do survive are the one who have succeeded in the game of 'selfishness'. Those that don't failed. Where is the contradiction? Obviously not every gene that has ever occurred can survive.
As to whether organisms are 'mere vehicles' for the propagation of genes, you'd have to say more what you mean by 'mere vehicles', and what you think Dawkins means by that. I don't have the book at hand, so I have no idea what his exact phrasing was.
And again, 'doing its job' is vague enough that I don't see how Dawkins would disagree with it. Who assigns the gene its job? Do you mean that each gene has a fixed, predetermined function it must fulfill? Or do you just mean it in the trivial sense that it contributes to the phenotypic adaptation that was selected for (and that was the reason why the gene was selected for)?
Perhaps this was not made clear enough. Dawkins has no teleological concept of the purpose of life as the perpetuation of the gene. He is not Aristotelian. The whole point of evolutionary biology is that it does not deal in terms of final causes.
The genes also do not have a 'purpose' of existence. They are just there. However, given that they exist, the ones who 'behave' 'selfishly' (with respect to their various environments) will tend to be propagated faster than the ones who do not.
Take this paragraph of yours:
Imagine one day if the gene wants to be less "selfish" and stops replicating. Our immune system will start to fail if our immune cells fail to divide. The genes that encode the precious protective antibodies will not be passed on to daughter cells, and DEATH will be the final verdict.
This is exactly Dawkins' point. If a gene is not 'selfish' enough, then it will fail to propagate. Therefore, all the genes that are 'successful' today are those who succeeded in the game of 'selfishness'. The process of natural selection demands that 'selfish' genes are selected for. In no way does Dawkins deny the existence of 'unselfish' genes (obviously bad mutations exist!). And, certainly, all genes follow the laws of physics in their chemical interactions --- they all 'do their job' in your sense. It just happens that those who have properties (relative to their environments) that favour their own propagation tend to propagate more successfully.
Also, Dawkins clarifies his views on complexity in the RIP article.
But of course it is abstract, simplified and distorted. This is what models are, and that is what gives them their usefulness. It is the very property which made my model useful to Mackie and which stimulated his useful contribution. Models do not aspire to mimic reality faithfully. If they did, they would not be models, they would be reality. In physics, for instance, it is sometimes convenient to imagine a body - it may even be described as a train - travelling at nearly the speed of light past an observer, who sees the passengers hideously foreshortened. Only a pedant would point out that trains can’t go that fast, and that in any case the observer wouldn’t have time to see the passengers. If a philosopher made such an objection against the writings of a particular physicist, we could justly conclude that he or she did not understand the first thing about physics, since all physicists make use of such simplified models.
He has no quibble that gene-level models are not reality. They are not meant to be reality. They are just meant to demonstrate certain salient aspects of reality. Of course there is complexity. But there is also, at a basic level, selection for 'selfish' genes, and this is what the models of population genetics (which, by the way, always include some crude forms of envirnomental interactions anyway --- selection cannot operate without environmental interactions) are meant to demonstrate.
First and foremost, my disagreement with Dawkins' lie in the perspective of an organism. He saw the organism as a vehicle for the perpetuation of 'selfish genes', I saw it as an emergence of genes, biomolecule and our environment.
Secondly, there was an rhetorical call for a "rebellion" against the "selfish gene" so to speak. I have taken my arguement further and painted a scenario. The organism, say Man for example, makes a conscious decision to migrate to an environment whereby the gene is not required. In a sense, I wish to point out that organisms are NOT just mere vehicles for the "selfish gene", BUT they DO HAVE SOME SAY over whether the gene can be perpetuated so to speak. Take for an example, a particular "selfish gene" that has propagated itself and encodes a product that allows Man to survive on Earth over the stretch of evolutionary time. One day, Man makes a decision to migrate to Socrates Planet. In the face of encroachment by mutagens, this gene would be deleted from the gene pool of the new Socrates Planaters in no time since it is no longer needed for survival by Socrates Planeters.
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