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As a biology and economics major this is an interesting analysis however, I believe that Axelrod is mistaken in using a game theoretical approach to this biological process. In order for this to be appropriately considered a prisoners’ dilemma the players should be rational actors (or at least conscious players), which in this instance the chromosomes are not. The homologous pairs of chromosomes in oogenesis have neither the capacity to deviate nor are they "aware" of the incentive to do so. These occurrences in egg formation are the result of the failure of the microtubules, responsible for separating the tetrads or homologous pairs during meiosis, to properly connect to the chromosomes’ kinetochores and have nothing to do with the "desires" of the chromosomes themselves. Furthermore, the equilibrium of the prisoners' dilemma is that both players should defect, so if somehow these macromolecules were playing this game, chromosomes in every division would be inclined to defect, or fail to split properly in order to stay in the egg forming cell. If this were the case, we would expect that every egg, and every child arising from those cells, would have excessive genetic material and would suffer from the physiological consequence of that. This is clearly not the case as most children born have the typical diploid distribution of genes. Also, the body has mechanisms that destroy gametes with excessive or insufficient genetic material, which I think might mitigate the prospective "advantage" a chromosome might "feel" in attempting to gain admittance to the ovum; if a chromosome, or set of chromosomes, were able to cheat their way into the egg cell, it would either be destroyed, or give rise to an organism that was less fit, or at the population level, unable to produce the most offspring, which is the evolutionary goal of organisms. Biology and game theory have many areas of overlap, but Axelrod's anthropomorphic view of the genetic material has caused him to attempt this unwarranted association.

Claire,

I think there may be more to the idea than you are allowing. It first came out, I think, in a 1981 Science article Axelrod co-authored with W.D. Hamilton. That's *the* Hamilton of "inclusive fitness." The context here is repeated games, not one-shot games. Indeed, it is because genes are interacting in a repeated game that cooperation can evolve and I think that was their main point. And, speaking of evolution, it's evolutionary game theory at work here, not rational choice theory. As you know, there is a kind of overlap because the ESS will mimic the probabilities of the Nash equilibrium in mixed strategies.

The notion might be all wrong. I wouldn't know. But it should be treated as a serious one given 1) the source and 2) the variety of equilibria in repeated games.

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