Comment by uplifter
4 hours ago
> What is the algorithm implementation when it comes to the physical world?
It is the physical world, nature is the implementation of the natural selection algorithm. Yes, the strong force is part of the implementation, because the strong force can play a role in selection events, cf nuclear bombs and radiation. The gravitational pull of remote galaxies can also influence selection events by changing planetary orbits minutely.
I don’t see these as problems for my argument because I am not the one claiming they encode an objective, I just see them as natural forces which can influence selection without any overarching purpose or goal. It is those claiming natural selection is an optimization process who must show how it could work. The onus is on them to show where their supposed objective of natural selection is encoded in its implementation.
> If you create selection pressure, and have a reproductive system that allows for mutations, then you may end up an "implementation" that encodes the goal implicit in the selection pressure.
What goal are you referring to?
> But anyone who messed around with genetic algorithms or artificial life in the 90s knows that you can trivially start out with no resemblance to "the goal" at all. Where life on earth in aggregate or any specific example of it in particular might be along that pathway is similarly impossible to say.
I am one of these people, but I don’t know what goal you are saying these systems came to demonstrate. Are you saying these artificial evolution systems had objectives they pursued? What caused them to follow these objectives? What is this “pathway”?
>Consider the well-documented case of moth evolution in industrial (and later, post-industrial) northern England. Their camouflaging wing tones changed to respond to the typical color on vertical surfaces, twice within a human generation or three. Was "the goal" flexible coloration across generations, or was it "light, then "dark" and then "light" again?
There was no goal at any point in the process. Moths with colors that matched their contemporaneous environment were less likely to be eaten by predators than those which stood out. Calling it a goal is a confusion, its trying to add a conceptual framing that isn’t necessary and adds nothing to the understanding of the system. Neither the soot levels in the air nor the birds hunting for moths have a goal of adjusting the balance of moth coloration phenotypes. They are just the context, along with everything else in their environment, in which evolution of moth coloration may occur.
In what sense is there any goal in the example? And if it is a goal, why is it not optimization? I claim there is no goal, no optimization objective to natural selection. Its not just a philosophical side question, it is the question.
edit: typo
> It is the physical world, nature is the implementation of the natural selection algorithm.
But you don't know (and to some degree, cannot know) which parts of it. So you cannot really know if the implementation encodes a goal or not.
> What goal are you referring to?
Whatever goal was being used in the case of genetic algorithms or artificial life systems. Those systems have goals, but the early stages do not embody the goal in any way you could recognize.
> There was no goal at any point in the process.
So in the case of natural evolution, we happen to agree. However, I don't agree with your claim that "the implementation must embody the goal" is a useful way to think about this, and I also have some sympathy for the idea that there could be huge-time-scale teleology associated with evolution that we cannot discern.
Its conceivable that the universe could encode a goal somehow, after all its so vast, but that conceivability alone is not evidence for the existence of an encoded goal any more than the conceivability of extra-terrestrial intelligence, or of a higher design to reality, is proof of their existence. What science tells us is that the only goal nature seems to embody is following the physical laws we've been able to determine, and nothing more. I'd apply the same interesting hypothesis status to huge-time-scale teleology that we cannot discern, and perhaps it is both real and we will never be able to discern it. Personally I find the notions very interesting, but I don't see reason to believe in them. If there were good evidence for them, they'd be the subject of scientific study already.
But we seem to agree that natural selection doesn't have a goal. In my observation, any purported overarching goal that is ascribed to natural selection, including the measure of inclusive fitness[0], can be reduced to some function of the context in which it is being observed, like moth coloration was influenced by soot levels.
As to my main claim, I do believe it is necessary that an encoding of a goal is necessary for choice among actions in pursuit of a goal, because some kind of reference to a goal is necessary to compare options in a decision algorithm. In the case of a-life systems which have goals, that encoding is somewhere in the algorithm of evolution rules combined with the initial state of the simulation. In the case of nature, I don't see a place where that encoding could exist, except the trivial "goal" that all elements will follow the laws of physics.
Please note though that I never put it that "the implementation must embody the goal," I was more careful with my language by saying that it must have an accessible or working encoding of the goal, one its decision process or evolution rule would need to reference in order to make decisions that favored it. The encoding need not be internal (so embody is definitely not necessary), and none of these things are necessarily explicit or well partitioned (e.g. an evolution rule can implicitly encode a goal).
edit: addendum: [0] On inclusive fitness being reducible to situational factors, I'm just following the direction of M.A. Nowak, C.E. Tarnita and E.O. Wilson on this: https://www.nature.com/articles/nature09205