Capitalist biology?

Almost exactly a year ago I speculated about how ethnocentrism, racism and various other kinds of local identifications in human society might partly be explained evolutionarily. Here is what I wrote then, which I mostly still agree with. In the context of reading The Selfish Gene I would like to add one other point. The mathematical determination of degree of genetic relatedness between individuals in a group, as described by Dawkins and presumably as enumerated by W.D. Hamilton, shows by implication the minimum number of relatives necessary to sacrifice oneself for in a genetically sustainable way. For example, since siblings and children share half their genes with a given individual, in order for altruism towards them to be good for the continued survival of one’s genes the altruistic act has to have a benefit for at least two of them that equals or exceeds the loss incurred by the individual.

Even evolutionary biologists acknowledge that these ratios are somewhat misleading in the sense that in reality one’s genes are not 50% identical to one’s children or siblings but something like 99.5% identical, since roughly 99% of one’s genes are the same in all humans in the world. Just the additional 1% is the whole from which the kinship ratios are derived. Now, I do not dispute that humans and other animals show marked preferences for their kin over other members of the species and even pretty fine gradations between individuals of different levels of relatedness to them. But it seems intuitively wrong when scientists like Dawkins insist that this sort of discrimantion and favoritism only pertains among closely related individuals, in other words that the 1% of genes not shared by all humans (or other members of a given species) actively shape altruistic or cooperative behavior to perpetuate copies of themselves, but the other 99% are essentially passive in this regard. Nor do I believe that they are claiming this, but it seems to me to be one implication of the somewhat disingenuously precise ratios. Whereas, if we apply the same reasoning to the entirety of the genome, one would expect to generally see a preference for members of one’s own ethnic group or geographical area, preference for members of one’s own species over members of other species, and even a preference for more closely related animal groups like mammals over more distant groups like insects. And, at the risk of both generalizing and stating the obvious, it seems to me that is exactly what we do see. It all depends on context. For instance, generally it seems better for humans to cooperate to some degree, both because of the costs of competition for any given individual and because of the relatedness between them. But if a conflict arises between groups, it is evolutionary sensible to support the group to whom one is more closely related. Hence perhaps the frequent exemption of soldiers from the general prohibitions on killing and violence. This might seem to be begging the question, as one might ask why group conflicts would develop if cooperation was better on the whole. But conditions are always changing, and if a group were suddenly to find itself for example in possession of a valuable natural resource ownership of that resource, both for themselves and other groups, might override more communal considerations.

In any case, I have already talked about all this before, and I suppose what I am trying to get at is that the limiting factor for altruism seems to me to be probably less the proportion of total genes shared, which between members of any one species is overwhelming, than the efficacy of any particular altruistic acts. Dawkins himself acknowledges this by mentioning the “law of diminishing returns” and provides an example which I quoted in my earlier entry:

“Kin selection is emphatically not a special case of group selection…If an altruistic animal has a cake to give to relatives, there is no reason at all for it to give every relative a slice, the size of the slices being determined by the closeness of relatedness. Indeed this would lead to absurdity since all members of the species, not to mention other species, are at least distant relatives who could each therefore claim a carefully measured crumb! To the contrary, if there is a close relative in the vicinity, there is no reason to give a distant relative any cake at all. Subject to other complications like laws of diminishing returns, the whole cake should be given to the closest relative available.?

So the main issue here is not that the individual has no genetic incentive to help out more distantly related individuals but that dividing one’s own resources among everyone who has some claim to it will divide it up so finely that it will wind up not doing anyone much good.

2 Responses to “Capitalist biology?”

  1. Dave Says:

    These altruistic tendencies are just mechanisms that, on average tend to perpetuate ones genes. I don’t know if they work so rationally. For instance I would rather eat a cow than a cockroach despite my closer genetic similarity to cow. Also these preferences certainly can be seemingly non-productive in cases where humans adopt other people’s children. The drives that promote a genes survival take on a life of their own. In some species, such as birds this is taken advantage of to the extent that it must be resisted. For example cow birds and cuckoos. Do these species exist in human form? One dares not ask.

  2. Curt Says:

    I don’t necessarily disagree with you, but I don’t think “altruistic” genes have anything to do with preferring to eat a cow to a cockroach. Cows are presumably a better nutrition source than cockroaches, or are more easily digested, or at least taste better, which probably indicates that they are a more natural food source. Since we’re not talking about an individual human sacrificing himself here, his best strategy would be to eat whatever is best for him nutritionally. It might be better for cows to predominate than cockroaches from the standpoint of human genes, but it is best of all if they themselves predominate, which they can do by giving themselves the best nutrition possible. Incidentally, I don’t know if this is a perfect example, since in some parts of the world I believe people do eat cockroaches, but it is at least more in the nature of the behavioral decision that needs to be made, I believe. In any case, we can at least say that most people are more likely to feel bad about killing or eating a cow than a cockroach, which I think should count for something. It is at all events necessary to bear in mind that evolutionary altruistic tendencies, if they in fact exist, should logically be fairly easily overriden by considerations of one’s own personal good, unless the comparatively greater benefit from altruism is extremely stark and clear-cut.

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