Thursday, June 04, 2015

Algorithms, Searches, Dualism and Declarative Computation. Part 3

Is evolution a declarative process?

In the last part of this series I described a recent paper from ID gurus Dembski, Ewert and Marks (DEM for short) as seen through the eyes of atheists Joe Felsenstein and Tom English. As I said in part 1 the debate here is not so much about DEM’s (correct) mathematical results but more about what they mean for evolution.

In their analysis of DEM’s paper FE make some cogent points. One point in particular struck me as not only significant but also as highly ironic:

Are “searches” search algorithms?
Mathematicians and computer scientists working on optimization are accustomed to investigating the properties of algorithms that try to maximize a function. Once an algorithm is given, its behavior on different functions can be studied mathematically or numerically. DEM do not make this separation between the algorithm and the function. Their definition of a “search” includes both the algorithm and the function it encounters. As an evolutionary algorithm may have different results on different fitness surfaces, in their argument the same evolutionary model can be two different “searches” if it encounters two different fitness surfaces. As we have noted, even “searches” that do not try to maximize the fitness are included in their space.

The point FE are making here is that the optimisation problem can be thought of as distinct from the search algorithm. In effect they have resolved the evolutionary question into two parts. That is, the problem statement and the underlying imperative algorithms which are used to search for a solution to the problem. This looks very much like a declarative computational paradigm where the problem statement defines a mathematical constraint, a constraint which then determines a search space. The search space is then traversed by very basic and routine imperative algorithms.

This is all very ironic. Declarative computation is teleological in as much as the problem statement effectively defines the sought for end result. In declarative computation the problem statement generates the basic imperative search algorithms needed to find a solution. But conceiving evolution in this teleological way is not going to sit very comfortably with an atheistic world view which is likely to see the laws of physics as goalless imperative processes that relentlessly march on regardless of end results. But the irony is that DEM have come to the rescue of the atheists! They have conceived a very general model that dissolves these potentially teleological considerations into an entirely imperative process! But this is no doubt inadvertent on DEMs part; in fact it is a side-effect of the North American Design community’s explanatory filter epistemic, an epistemic whereby imperative natural processes are very much seen as the anti-thesis of intelligent intervention. See for example my blog series on Dualism in the North American Intelligent Design Community; that series can be picked up here:

In that series of posts I consider a web article by ID guru V J Torely where it is clear that nothing like a declarative paradigm so much as enters his head. Torely, like DEM, sees “natural processes” as mindless imperative objects that don’t naturally generate anything very significant. Hence DEM have simply created a piece of otherwise valid mathematics that fulfils their expectations: Viz: They show that the big problem for imperative processes as conceived by DEM is that these processes have such tiny probabilities of returning “small target” results. Thus, the only apparent solution, seemingly, is to provision imperative systems in advance (i.e. front load them) with sufficient information to considerably enhance the chances of the search generating results in realistic times. This “front loading” does the job of what DEM call “active information” – whatever that means.

It is to the question of the provision of “active information” that FE turn. They consider how this “active information” could be present in “natural systems”.  FE’s strategy is to invent a very simple toy model of “evolution” and show that it has “active information” built into it. As they point out, their model isn’t meant to be realistic but rather simply shows how fairly elementary mathematical conditions are sufficient to introduce large to enormous amounts of “active information”. To this end they introduce the concept of the Greedy Uphill Climbing Bug (GUCB). This is a “greedy” algorithm which always moves in the direction of greatest fitness in configuration space. FE have even done a simulation where this “bug” moves around in a configuration space where the fitness surface is a white noise surface  – even this case has a lot more“active information” than DEM’s base line “random search”.  Moreover, as Joe Felsenstein has pointed out in his previous post on this subject (see here) the laws of physics very likely considerably smooth out the fitness surface thus adding even more “active information”.  To quote FE:

Dembski and Marks would consider these smooth fitness surfaces to have large amounts of “active information”, because they lead to much greater success at reaching any target which includes the genotypes of highest fitness. So these two effects do not require any intervention of a Designer, just the presence of genotypes that have fitnesses, and the action of ordinary laws of physics. Some, quite possibly all, of Dembski and Marks’s “active information” is present as soon as we have genotypes that have different fitnesses, and genotypes whose phenotypes are determined using the ordinary laws of physics.

OK, so physics very plausibly adds a lot of so-called “active information”. But this begs some big questions: Is that information enough?  And, of course, just where does this information come from? That latter question is in effect the same as asking the question “Where do the laws of physics come from?”. Joe Felsenstein, having demonstrated to his satisfaction that the laws of physics are evolution friendly passes this big question onto the physicists.  But before we even get to that question there are also some cutting questions I would like to raise in connection with the general ideas at the heart of the model FE use.  I hope to look at all these questions in the next part.

Before I finish this part I would like to note that FE have implicitly used the explanatory filter epistemic with its inbuilt dichotomy of God Intelligence vs. Natural Forces. That is, having provided a plausible case for an evolutionary friendly cosmos FE’s conclusion is that natural processes, rather than “intervention of a Designer”, are sufficient to produce life. This is the theological weakness that I have repeatedly  identified with the North American ID argument (as has Ken Miller); for if it can be plausibly shown that known so-called “natural processes” can generate life, the ID community’s explanatory filter with its inbuilt dualistic assumptions becomes a lethal weapon against theology; in short that epistemic cuts lethally both ways! It might be OK for archaeology or 2001 Space Odyssey but it's bad for theology!

FE’s plausible case for “active information” effectively residing in the laws of physics also shows up the right-wing* Christian community’s misunderstanding of the second law of thermodynamics. As we saw in this post right-wing Christians make no allowance for the kind of “active information” that FE have attempted to identify in “natural processes”. As we know life, using the “active information” of natural genetics, annexes and organises increasing amounts of matter without violating the 2nd law. If FE are right, then in evolution it is the laws of physics which impose this organising “active information” – and if isn’t the laws of physics that have the requisite “active information” then perhaps some other Divine provision does. However, once again we see that the Christian-right are barking up the wrong tree in a very embarrassing way.

FE’s thinking is plausible although it does in my opinion have some salient problems which I hope to pin point next time. Nevertheless they have at the very least succeeded in exposing the weaknesses of the kind of ID thinking with which they take issue.

* I use the term "right-wing Christian" here to identify a loose alliance of right wing evangelicals, fundamentalists and conspiracy theorists. Generally they have a strong tendency to fall on the right of the political spectrum and in particular they usually oppose the academics of the public sector.

Some relevant links:

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