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  Topic: Missing Shade of Blue Thread< Next Oldest | Next Newest >  

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Joined: Feb. 2008

(Permalink) Posted: Dec. 20 2008,19:33   

Quote (Missing Shade of Blue @ Dec. 20 2008,13:02)

2) Our inductive biases are not particularly successful, and in so far as they are, it's just a lucky accident. Think of all the other species that went extinct due to bad inductive biases (the dodo, for instance). I don't find this satisfactory either. While evolution has no doubt sampled a large number of different sorts of inductive biases, and many have proved unsuccessful, it is also true that the number of biases sampled is an infinitesimally small proportion of the total number of possible biases. And yet it managed to hit on ones that have allowed a number of species to survive for millions of years after the respective biases evolved. This seems too improbable to be explicable as a lucky accident. So we should expect that the sampling wasn't random. There was some kind of search mechanism that looked for biases that more or less match the natural structure of the world. What I have been arguing is that this search mechanism could not have been natural selection, because when you lack information beyond a certain point in time, it radically underdetermines your judgments about which predicates are natural.

This seems to boil down to an argument from personal incredulity. You find it unsatisfying or extremely unlikely, but can you back that dissatisfaction up with a specific, real world example of where evolution is insufficient ? The grue/bleen example definitely fails the real world criteria, at multiple levels.

We appear to live in a universe that is consistent enough for induction to be useful. If you accept that, then evolution producing creatures which successfully use induction should be completely unsurprising. Successfully approximating the future can help you reproduce, and biochemical processes can produce such approximations. If the inductive biases of our early hominid ancestors gave them an advantage, it was because those biases in some way reflected the real world. In a relatively consistent universe, it follows that their successful descendants would tend to inherent biases that reflected the real world they lived in.

Your argument that evolution needs to predict certain things (picking the "right" biases millions of years in advance) looks like it can be rephrased as a statement that the pace of change of our environment has been sufficiently low to avoid complete extinction. Looking at the actual characteristics of our planet and biology, this does not seem especially remarkable. If you are going to claim that it is beyond the reach of observed mechanism, you'd better come up with some specific data.

  131 replies since Dec. 20 2008,09:40 < Next Oldest | Next Newest >  

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