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Contingency Readings

In Class matters on April 21, 2010 by Joshua Smart

Gentle Fellow PhilSciers,

The readings folder for next week contains three required readings. The primary one is John Beatty’s formulation of the evolutionary contingency thesis (ECT) which states that there are no distinctive laws of biology. For Sober’s response you can ignore the parts about Rosenberg. We’ll just be concerned with the first five page, where he is directly interacting with Beatty. Finally, Brandon provides a third view of the relationship between laws and biology, arguing on a rather different tack than Beatty or Sober.

There is one reading in the recommended folder–a recent piece by Morgan supposedly providing a counterexample to Beatty. It’s worth skimming to think about the ways in which we might learn that Beatty is wrong.

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Niche Construction and Miles Davis

In Discussion on April 13, 2010 by Joshua Smart

[Looking at Wenwen’s post, I’m not entirely sure mine is sufficiently different to warrant a new thread. If not, sorry.]

I think that several little questions that I had about this weeks readings can be summed up one bigger one: So What? Lewontin and Odling-Smee seem to think that niche construction is a revolutionary idea that will drastically alter the way we understand evolution. But I don’t see it. It shows us that evolution can be more complicated than how we often think about it–which is certainly good and important–but it does seem to entail any large scale upheaval. After all, wouldn’t we expect these constructive behaviors to have some genetic basis if they’re going to spread throughout the species and last for generations?

I see the change as something like the following crude example. Resources are on a high table, out of reach of most or all members of a species. Normally we would expect tallness to be advantageous and lead the population to evolve to be taller. Now, we should realize that evolution will favor members of the species that can build stairs as well. Useful, but not earth shattering.

Am I missing something?

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Non-causal counterfactuals

In Discussion on March 22, 2010 by Joshua Smart

[For the record, I’m rather angry at WordPress that I lost this post the first time around.]

I have no doubt that Lewis has considered the following objection, but either I missed it or he does so elsewhere. Any suggestions on what response he makes/might make?

Suppose that c (alone) causes both e and f and that c []–> ec []–> f~c []–> ~e, and ~c []–> ~f. It would appear that f []–> e and ~f []–> ~e follow. But if that’s the case, then doesn’t Lewis have to say that that f also caused e?

An example in English. Suppose that my genetic makeup is such that in each possible world in which I exist my heart beats irregularly. Suppose further that there is only one medication that can fix this, however it is a side effect that my ears swell up to a size they never would have otherwise. On Lewis’ theory, it seems as though we have to say that my heart beating rhythmically caused my ears to swell since, had my heart not beat rhythmically, my ears would not have swollen.

A few possible responses that don’t seem right:

  1. Lewis seems at pains to reject backtracking through counterfactual dependence. So we can’t say something like, “if my heart hadn’t beat rhythmically then I wouldn’t have taken the medicine and then the medicine wouldn’t have caused my ears to swell.
  2. He might try to appeal to a causal chain, but one can imagine a case in which e and f are both immediate effects of c (e.g. are two adjacent neurons simultaneously stimulated by a third neuron).
  3. He always could bite the bullet, but I doubt he does here given how much he avoids it throughout “Postscripts”.

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Testing Adaptationism Without (O)

In Discussion on March 3, 2010 by Joshua Smart

I had a brief thought while reading the critique of Orzack and Sober. It seems to me that even if Brandon and Rauscher’s critiques of (O) and its test are right on, O&S might still stand their ground about testing adaptationism. Suppose 45 of 50 studies clearly showed that the trait under investigation was locally optimal. Knowing that natural selection is the optimizing feature of evolution, wouldn’t be reasonable to say that we have some pretty strong evidence for adaptationism? (That is, some reasonable notion of adaptationism, not necessarily (A)).

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Questions About Robustness Analysis

In Uncategorized on February 22, 2010 by Joshua Smart

I have a couple of questions about W’s RA paper of the “I’m pretty sure I’m missing something” sort. So if anyone has ideas of what I’m missing I greatly appreciate the help.

1. The key to W’s response to O&S seems to be the nature of step 3.

[T]he third step of robustness analysis involves interpreting the mathematical structures as descriptions of empirical phenomena. In the predation case, theorists have to decide how two coupled differential equations will explicitly map on to the properties of real or imagined predator-prey systems. (738)

But I’m not sure what this involves. The most natural way for me to read it is to say that the investigators are now deciding what the link is between the model descriptions and the models (and on to targets). But surely this has been done already when the initial model descriptions were generated.

When W explains how this answers O&S he says,

Standard issues in confirmation theory concern whether a particular kind of model, such as the logistic growth model, is confirmed by the available data. However there is a prior confirmation-theoretic question that is often asked only implicitly: If the population is growing logistically, can the mathematics of the logistic growth model adequately represent this growth. (740)

The way I naturally read this, such a confirmation is trivial. What is it for a population to grow logistically except that its growth can be described by a logistic function?

W goes onto say that confidence in a positive answer to the question above is bought by “demonstrating that the relevant mathematics could be deployed to make correct predictions” (740). What this means beyond “theories are constructed using the maths and predictions are compared to real-world events” I don’t know. All the above only seems to indicate that the models that go into the hopper for robust analysis were developed in normal scientific (empirical) ways (and therefore RA is not non-empirical confirmation). But this is exactly what I take Levins’ response to be at the beginning of the paper (on 733) (though W has tidied up to what Levins’ response may apply, i.e. his more complex formulation of robust theorems).

2. My other confusion concerns the “two key questions” on page 739. W takes answering these as the key to ensuring that the antecedent of the conditional holds, and that all the ceteri are paribi. They are:

1. How frequently is the common structure instantiated in the relevant kind of system?

2. How equal do things have to be in order for the core structure to give rise to the robust property?

Answering the second is essentially the fourth step of analysis, so I’m not quite sure what it’s doing here. But that is a minor complaint.

W’s discussion of the first question seems to indicate that the greater the variety of models that are put into the hopper is, the more likely it is that the robust property will be true of target systems, since it is more likely that the common causal structure will actually be present. But then he also says that “This would allow us to infer that when we observe the robust property in a real system, then it is likely that the core structure is present and that it is giving rise to the property” (739). Wouldn’t the conditional representation of robust theorems have to be a bi-conditional for this to be the case? He says that the question is best addressed empirically, so the “relevant kind of system” is indeed talking about target systems. So in applying this to the Volterra example, would it be that various pred-prey systems were examined, the various models were developed that fit those systems, and then the models were all thrown in to the hopper and Volterra came out as the robust property with the given antecedent as the core structure? And if we studied a lot of systems in generating many models, then we can be more confident that we’ve really pared the core down to the important parts for the robust property. Is that what he’s saying?

In sum: I am confused. Thoughts?

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Alternative Categories

In Uncategorized on February 15, 2010 by Joshua Smart

Collin and I have been working on a paper to respond to Witt with the following structure: 1. What are Witt’s categories? 2. What is wrong with Witt’s categories? 3. Alternative categories. 4. Examples of alternative categories.

Below are brief rundowns of our proposed categories and Collin will post our analysis of Witt’s categories. We greatly appreciate any feedback you can give. Are they sensical? Do we miss any major ways in which evolution is applied to economics? (Especially appreciated from economist friends).

—–

  • Universal Darwinism

Universal Darwinism is a term first coined by Richard Dawkins in 1983, but the locus classicus for the concept is Daniel Dennett’s 1995 book Darwin’s Dangerous Idea. This approach sees Darwinian evolution as an algorithm involving variation, selection, and retention that is substrate neutral. Darwin described how this algorithm applies to biological systems. Economists who employ UD attempt to describe how it applies to economic systems. This is not meant to imply anything concerning the interaction or relationship of biological and economic systems, but merely uses Darwinian principles as a heuristic to understand economic systems.

  • Evolutionary Metaphor/Analogy

This approach is not committed to Darwinian evolution actually occurring in economic systems (as UD is). Instead, it attempts to use metaphor or analogy to biological evolution to aid in the description of economic systems. Those who employ this strategy attempt to abstract away from the particulars of biological evolution to generic concepts that are present in economic systems as well. They may attempt to draw specific analogies between the systems (e.g. find economic analogues for genotypes and phenotypes), or they may attempt to abstract away to the most generic principles of evolution (e.g. Witt’s “novelty emergence and dissemination”).

  • Evolutionary Modeling

This approach applies mathematical models that were originally developed to describe the evolution of biological systems, and employs them to describe the evolution of economic systems. Using these models does not commit one to any claims about the connection between the underlying entities and principles governing economic and biological systems. That is to say, the motivation for employing evolutionary models is pragmatic, not metaphysical.

  • Evolutionary History Acknowledgement (working on a pithier name for this one)

This approach to economic research incorporates information about the evolutionary origins of the preferences and behavioral tendencies of economic agents. This approach does not borrow biological evolutionary explanations or analytic tools to describe economic systems. Rather, it incorporates information provided by evolutionary biology into attempts to understand economic agents.

  • Summary

Our distinction between these potential meanings of “evolutionary economics” arises from what is being borrowed from biology. In EHA, it is information concerning the nature of economic agents. In evolutionary modeling it is mathematical machinery. In evolutionary metaphors and analogies it is general features. And in UD, it is nothing (rather, shared principles are employed).

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Boiling and disjunctive laws

In Uncategorized on February 15, 2010 by Joshua Smart

This is a minor point, but I note that Sober is wrong in his description of the law concerning boiling water. The law in this case is that water boils at 100C. Having the ambient temperature be over 100C is one way to raise the temperature of the water to 100C, but the relevant fact is that the water itself reaches the boiling point. Also, the temperature of the water will not exceed 100C until it has completely transitioned to gas phase.

Can anyone think of a law that actually has the sort of disjunction Sober is looking for?