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Carl_Shulman comments on The Baby-Eating Aliens (1/8) - Less Wrong

42 Post author: Eliezer_Yudkowsky 30 January 2009 12:07PM

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Comment author: Carl_Shulman 31 January 2009 10:47:57AM 0 points [-]

"I fear that you have not managed to convince me of this. If the general idiom of children in pens is stable, then the adults contributing lots and lots of children (as many as possible) is also evolutionarily stable."

I have a tribe of Babyeaters that each put 90% of their effort into reproducing, and 10% into contributing to the common food supply of the pen. This winds up producing 5000 offspring, 30 of which are not eaten, and are just adequately fed by the 10% of total resources allocated to the food supply. Now consider an allele, X, that disposes carriers to engage in altruistic punishment, and punishment of non-punishers, in support of a norm that adults spend most of their effort on contributing to the food supply (redirecting energy previously spent on offspring to be devoured with thermodynamic losses to the production and maintenance of offspring that will grow into adults). Every individual in the tribe will tend to have more surviving offspring, and the group will tend to be victorious in intertribal extermination warfare. Group selection will thus favor the spread of X, probably quite a bit more strongly than it would favor the spread of an allele for support of the babyeating norm (X achieves the benefits of babyeating while reallocating metabolic waste on devoured babies). The more closely X aligns offspring production and food contribution, the more it will be spread by group selection and the more it will reduce babyeating.

In a world with many groups, all engaging in winnowing-level babyeating, allele X can enter, spread, and vastly reduce babyeating. What is unconvincing about that argument?

"Suppose that all Babyeaters make equal contributions to the food pen; their leftover (variance in) food resources could be used to grow their own bodies, bribe desirable mates (those of good genetic material as witnessed by their large food contributions), or create larger numbers of offspring."

Different alleles might drive altruistic punishment (including of non-punishers) in support of many different levels of demand on tribe members. Group selection would support alleles supporting norms such that the mean contribution to the pen food supply was well-matched with the mean number of offspring contributed to the pen. Variance doesn't invalidate that conclusion.