Richard Dawkins' The Selfish Gene proposes a new way of looking at biology, one that reverses the relationship between genes and organisms. Whereas biologists have tended to look at the organism as central and genes as interesting inasmuch as they affect the lives of organisms, Dawkins proposes that we look at genes as central and at organisms inasmuch as they contribute to the perpetuation of genes. He initially proposes this shift in the form of a mere metaphor: what would a gene think and do if it could deliberate about ways in which it might perpetuate its form? Well, it would look at the organism as a vehicle that it, alongside with other genes with whom it is cooperating, could use to make it to the next generation. A survival vehicle. It would look at the organism as a "lumbering" robot that it could use to manipulate its environment so that opportunities and dangers to self-perpetuation could be dealt with. The book begins by employing this figure, which he calls a "subjective metaphor," promising to keep a "skeptical eye" on it: after all, metaphors tend to break down once one has over used them. And throughout the book he reminds the reader that his metaphor is just that. By the end of the book, however, Dawkins tells us that genes "come first in importance as well as in history." One who doesn't see how something lacking subjectivity could be of greater importance than its respective organism is left concerned that the author has perhaps traded his skepticism for something quite the contrary. But Dr. Dawkins would most likely reply to this concern by pointing out that the metaphor is just a mental shortcut and that the central conclusion of this book can be justified by a mathematical approach to genetics that sets the metaphor in question aside.
(The paragraphs that follow continue to give a basic exposition of Dawkins' book. By the end of July I hope to polish up this summary and to post some critical remarks as well.)
The initial thesis in this work is not that genes are more important, but that they are the natural unit of natural selection. In other words, we should think of the environment as selecting genes rather than selecting individual organisms or groups. Natural selection works over many, many generations, whereas individuals do not endure very long and hence are unfit to be the object of natural selection. Groups of animals last over many generations, but they do not have a fixed identity. They are, in Dawkins' words, too "wishy washy" to serve as the unit of natural selection, for what is selected must remain the same after selection as it was before. Groups, on the other hand, are always in flux: they do not, strictly speaking, keep their identity even one generation, let alone many. With the individual organism and group thus disqualified, Dawkins argues that the gene is the only candidate well-suited for being the object of natural selection. We cannot grasp why it alone qualifies, however, until we understand more precisely what Dawkins means by "gene."
To that end, two clarifications are needed, the first of which concerns the size of the gene. Before genes had even been imagined, Mendel proposed that a yet unidentified "atom of inheritance" played a key role in the handing down of traits from one generation to the next. Today, we call this atom of inheritance the "gene." As Dawkins notes, this term can be used to refer to a cistron (the smallest bit of information sufficient to guide the formation of proteins), but it can also be used to refer to something much larger. Instead of calibrating his definition to fit just one of these, Dawkins proposes a "fading" definition: whatever unit of information that tends to be transmitted from generation to generation counts as a gene, regardless of its size. A whole chromosome does not, according to this definition, qualify as a gene, for chromosomes last only one generation (at least in animals that rely on sexual reproduction). But units of information smaller than a chromosome tend to last more than one generation, and the smaller the unit, the longer it is likely to last. So the first clarification of the meaning of the word "gene" as used by Dawkins is that it is any sequence of DNA smaller than a chromosome but not smaller than a cistron.
The second clarification is that when he says that the gene is the basic unit of natural selection Dawkins has in mind not an individual gene but the population of genes of the same type. Consider how natural selection is the selection of something that lasts from generation to generation, but an individual DNA molecule lasts at most for a couple of months. The individual gene made of such molecules therefore cannot be said to act so as to preserve itself over many generations, nor can it serve as the object of natural selection. A population of genes of the same type, however, does last from generation to generation, thanks to the gene's copying fidelity. This population, therefore, has a longevity that far exceeds that of an individual gene or organism--in fact, Dawkins repeatedly likens its duration to immortality.
It is only by keeping this quasi-immortality in mind that one can rightly understand what Dawkins has in mind when employs the subjective metaphor of the gene acting selfishly. He does not mean that it hoards things for itself, but rather that it acts so as to preserve itself in existence indefinitely. Since the smaller the gene is, the longer it tends to endure, Dawkins jokingly remarks that his book should be called "The slightly selfish big bit of chromosome and even more selfish little bit of chromosome." While this alternative title is not very elegant, it does make it clear that the term "selfish" in the book's title refers to the tendency of a gene to find ways to perpetuate itself. He even states flat out that this potential for immortality is the "defining property" that makes it the natural unit of natural selection. And he notes, with gratitude that even the Oxford English Dictionary has adopted "tending to be perpetuated" as one of the meanings of "selfish," giving an example of a gene. And he closes the 30th anniversary edition (which has chapters added to the original) with a brief paen to the "immortal replicator."
It would be trivial to say that genes that tend to survive from one generation to the next can be imagined as striving to preserve their own existence. What is quite interesting in Dawkins' book is that he proposes that his subjective metaphor helps us to understand how both selfishness and altruism (in the more everyday sense of the terms) have arisen from natural selection. And that is precisely what he does with a plethora of examples in this book. I will not go over any of those examples in this summary. I will only point out one remarkable conclusion, i.e., that altruism in organisms "is explained by the fundamental laws of gene selfishness," is argued for by mathematical arguments. That is, he employs game theory to show that, just as certain strategies are more successful than others, so too genes promoting certain behaviors in organisms are more successful than others at replicating themselves from one generation to the next. Consider also how some strategies that seem to give an individual an advantage over others actually harm the individual when all other players have the same strategy. For example, if I am a cheater who accepts help given to me but never help others when in need, I will do well against others who are, as Dawkins puts it "suckers" who help others no matter what. But if everyone behaves in the same way as I do, then the population as a whole will do poorly. A population consisting solely of cheaters never prospers. If we look at this sort of behavior from a "selfish gene" perspective (i.e., with an eye to the strategy that would help a gene type to thrive), we can say that cheating is not an evolutionarily stable strategy (ESS). Thus Dawkins offers at least a partial explanation of why humans and other animals behave altruistically, at least on a good day.
Almost all of this book is focused on genetics, but in his perhaps most controversial chapter he turns to cultural forms and their neurological bases, the latter of which he calls memes. Memes are so named because of their similarities with genes. Both replicate, says Dawkins, and have a potential immortality in virtue of that power of replication. Unlike genes, as Dawkins notes, memes have no alleles, but they do compete with other ideas for space in someone's brain. Like genes, memes have no foresight, but we can use the subjective metaphor as a hueristic for understanding how they are likely to behave. Both genes and memes inhabit a host, but whereas genes construct their vehicles; memes do not. In this respect they are more like viruses, which Dawkins likens to a breakaway colony of genes that survive by moving from host to host. Like viruses, memes can sometimes act in a manner that benefits themselves while being harmful to others. Like viruses, memes can adapt by mutating rather quickly (in comparison with genes that have a native host); hence cultural diversity I believe that it is for that reason that Dawkins rejects application of kinship selection theory to memes. That is, kin selection theory--which is synonymous with gene selection theory--does not seem to be applicable to memetics. But that does not make memetics extra-topical. Rather, both selfish-gene theory and memetics are part of a bigger picture, which Dawkins calls "universal Darwinism." Both fall under this broader category inasmuch as they involve replication. Thus, when the author speaks of the "immortal replicator" in the last line of the anniversary edition, he is praising both the gene and the meme for their ability to find immortality.
(The paragraphs that follow continue to give a basic exposition of Dawkins' book. By the end of July I hope to polish up this summary and to post some critical remarks as well.)
The initial thesis in this work is not that genes are more important, but that they are the natural unit of natural selection. In other words, we should think of the environment as selecting genes rather than selecting individual organisms or groups. Natural selection works over many, many generations, whereas individuals do not endure very long and hence are unfit to be the object of natural selection. Groups of animals last over many generations, but they do not have a fixed identity. They are, in Dawkins' words, too "wishy washy" to serve as the unit of natural selection, for what is selected must remain the same after selection as it was before. Groups, on the other hand, are always in flux: they do not, strictly speaking, keep their identity even one generation, let alone many. With the individual organism and group thus disqualified, Dawkins argues that the gene is the only candidate well-suited for being the object of natural selection. We cannot grasp why it alone qualifies, however, until we understand more precisely what Dawkins means by "gene."
To that end, two clarifications are needed, the first of which concerns the size of the gene. Before genes had even been imagined, Mendel proposed that a yet unidentified "atom of inheritance" played a key role in the handing down of traits from one generation to the next. Today, we call this atom of inheritance the "gene." As Dawkins notes, this term can be used to refer to a cistron (the smallest bit of information sufficient to guide the formation of proteins), but it can also be used to refer to something much larger. Instead of calibrating his definition to fit just one of these, Dawkins proposes a "fading" definition: whatever unit of information that tends to be transmitted from generation to generation counts as a gene, regardless of its size. A whole chromosome does not, according to this definition, qualify as a gene, for chromosomes last only one generation (at least in animals that rely on sexual reproduction). But units of information smaller than a chromosome tend to last more than one generation, and the smaller the unit, the longer it is likely to last. So the first clarification of the meaning of the word "gene" as used by Dawkins is that it is any sequence of DNA smaller than a chromosome but not smaller than a cistron.
The second clarification is that when he says that the gene is the basic unit of natural selection Dawkins has in mind not an individual gene but the population of genes of the same type. Consider how natural selection is the selection of something that lasts from generation to generation, but an individual DNA molecule lasts at most for a couple of months. The individual gene made of such molecules therefore cannot be said to act so as to preserve itself over many generations, nor can it serve as the object of natural selection. A population of genes of the same type, however, does last from generation to generation, thanks to the gene's copying fidelity. This population, therefore, has a longevity that far exceeds that of an individual gene or organism--in fact, Dawkins repeatedly likens its duration to immortality.
It is only by keeping this quasi-immortality in mind that one can rightly understand what Dawkins has in mind when employs the subjective metaphor of the gene acting selfishly. He does not mean that it hoards things for itself, but rather that it acts so as to preserve itself in existence indefinitely. Since the smaller the gene is, the longer it tends to endure, Dawkins jokingly remarks that his book should be called "The slightly selfish big bit of chromosome and even more selfish little bit of chromosome." While this alternative title is not very elegant, it does make it clear that the term "selfish" in the book's title refers to the tendency of a gene to find ways to perpetuate itself. He even states flat out that this potential for immortality is the "defining property" that makes it the natural unit of natural selection. And he notes, with gratitude that even the Oxford English Dictionary has adopted "tending to be perpetuated" as one of the meanings of "selfish," giving an example of a gene. And he closes the 30th anniversary edition (which has chapters added to the original) with a brief paen to the "immortal replicator."
It would be trivial to say that genes that tend to survive from one generation to the next can be imagined as striving to preserve their own existence. What is quite interesting in Dawkins' book is that he proposes that his subjective metaphor helps us to understand how both selfishness and altruism (in the more everyday sense of the terms) have arisen from natural selection. And that is precisely what he does with a plethora of examples in this book. I will not go over any of those examples in this summary. I will only point out one remarkable conclusion, i.e., that altruism in organisms "is explained by the fundamental laws of gene selfishness," is argued for by mathematical arguments. That is, he employs game theory to show that, just as certain strategies are more successful than others, so too genes promoting certain behaviors in organisms are more successful than others at replicating themselves from one generation to the next. Consider also how some strategies that seem to give an individual an advantage over others actually harm the individual when all other players have the same strategy. For example, if I am a cheater who accepts help given to me but never help others when in need, I will do well against others who are, as Dawkins puts it "suckers" who help others no matter what. But if everyone behaves in the same way as I do, then the population as a whole will do poorly. A population consisting solely of cheaters never prospers. If we look at this sort of behavior from a "selfish gene" perspective (i.e., with an eye to the strategy that would help a gene type to thrive), we can say that cheating is not an evolutionarily stable strategy (ESS). Thus Dawkins offers at least a partial explanation of why humans and other animals behave altruistically, at least on a good day.
Almost all of this book is focused on genetics, but in his perhaps most controversial chapter he turns to cultural forms and their neurological bases, the latter of which he calls memes. Memes are so named because of their similarities with genes. Both replicate, says Dawkins, and have a potential immortality in virtue of that power of replication. Unlike genes, as Dawkins notes, memes have no alleles, but they do compete with other ideas for space in someone's brain. Like genes, memes have no foresight, but we can use the subjective metaphor as a hueristic for understanding how they are likely to behave. Both genes and memes inhabit a host, but whereas genes construct their vehicles; memes do not. In this respect they are more like viruses, which Dawkins likens to a breakaway colony of genes that survive by moving from host to host. Like viruses, memes can sometimes act in a manner that benefits themselves while being harmful to others. Like viruses, memes can adapt by mutating rather quickly (in comparison with genes that have a native host); hence cultural diversity I believe that it is for that reason that Dawkins rejects application of kinship selection theory to memes. That is, kin selection theory--which is synonymous with gene selection theory--does not seem to be applicable to memetics. But that does not make memetics extra-topical. Rather, both selfish-gene theory and memetics are part of a bigger picture, which Dawkins calls "universal Darwinism." Both fall under this broader category inasmuch as they involve replication. Thus, when the author speaks of the "immortal replicator" in the last line of the anniversary edition, he is praising both the gene and the meme for their ability to find immortality.
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