Sunday, February 8, 2009

Teaching evolution

It being Darwin’s 200th birthday this week, I wonder – do people cover the evolution ‘controversy’ when teaching undergrad phil sci? I have found that students tend to be pretty interested. So far I have never experienced any heated religion-based bother, and pro-evolution students are usually glad to gain ammunition. (I make sure that I stay ostentatiously neutral regarding religious and political issues more generally.) Perhaps my positive experience is not typical, I don’t know. My class is largely non-philosophy majors in St Louis.

The topic’s also an excellent illustration of how philosophy of science can add something over and above science itself – something that’s not always obvious to science majors.

Maybe much depends on exactly how it is taught. I’ve never just shown a video, such as the (decent) PBS one about the recent Dover trial. Rather, I teach it as a natural follow-on from earlier stuff in the course about testing and auxiliary assumptions. Briefly – I roughly follow the presentation in Elliott Sober’s phil bio textbook, emphasizing that intelligent design arguments require auxiliary assumptions about the nature of any designer in order to be testable. Of course, such assumptions about a designer are themselves hard to test, as Hume noted long ago. And a default assumption of an optimal designer runs afoul of actual organisms’ many imperfections. I.e. intelligent design is either untestable or falsified. Obviously, this contrasts with the situation with science.

I also like to add a straight science class on the wide range of evidence for evolution because I’ve found that usually only a few students, even biology majors, are aware of more than a small portion of it.

No doubt there are other ways of proceeding, and I’d certainly be interested to hear about those that seem to work well. But my point is more that I’ve found the experience surprisingly satisfying rather than depressing, and far from a creationist Trojan-horse ‘teach the controversy’ exercise. Accordingly, given the state of public debate in parts of the US at least, perhaps we all ought to be teaching this?

11 comments:

  1. At Pittsburgh, ID is discussed in an intro to philosophy of science course for HPS majors. We use it in the discussion of the demarcation problem (i.e., how to distinguish science from non-science), from the logical positivists onward. After reading the usual demarcation literature, my students were asked to read several sections from the ruling of Judge Jones, and write a short paper evaluating Jones' arguments. The students found this very interesting and produced good work; it was an overwhelmingly positive experience.

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  2. There is a series of articles by Michael Ruse and Larry Laudan in Science, Technology and Human Values from the 80s. Ruse argues that creation science is not science, and Laudan argues that it might be science, but it is bad science. I certainly agreed with Laudan that it is worth taking the time to subject the arguments to scrutiny rather than just ignore the issue.

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  3. Fortunately, in Europe (I cross my fingers) negationist of darwinism are a so small and discredited minority that there is really no need of presenting the discussion. This has been at least my experience.

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  4. The papers Anonymous mentions are collected in a volume by Michael Ruse called But is it Science?. These include writings by creationists, as well as Ruse's testimony from the 1980 - 81 Arkansas trial and the judge's decision. It is a good volume, but a bit dated now.

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  5. What sources do you use in the class where you present the wide range of evidence for evolution? I've looked before and not found the kind of single volume reference that I would like and that I could point my students to.

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  6. I teach evolution and creationism in several courses including an introduction to reasoning and in a history and philosophy of evolutionary biology.

    As for the intro to reasoning course (175 students) I teach Paley as an example of "inference to the best explanation" and then offer Darwin's response. The trick here is I'm allowing us to regard creationism (at least Paley's version) as "science" and see how it fares in certain questions. Like Robert, I follow Sober's treatment to some extent (naturally--he was my prof!).

    I like to teach evolution and creationism as a foil for more general philosophical issues. The course on reasoning is one example. Another example is to use the debate as a foil for talking about epistemology from Descartes to Hume. A natural conclusion for this line of thought is that creationists end up looking like skeptics--e.g. denying that fossils are any more than God's deception.

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  7. Like André Ariew above, I use the dispute in as an illustrative example in a variety of courses. If anyone is interested in teaching the matter in a creative way, check out Reacting to the past's 'Darwin Game'.
    Reacting games require students to reenact moments in history in the characters of the people who participated. The Darwin game focuses on the Royal society between 1861 and 1864, when Darwin was awarded the Copley medal. Students are required to argue in the characters of Richard Owen, Thomas Henry Huxley, Joseph Dalton Hooker, General Sabine and others. The game structure forces students to really understand the views, rather than just be able to repeat them when asked. In fact, when I played this game with my first year students last year, a couple confessed that playing the game had shown them that everything they had been taught about Darwin was wrong! If I had told them the same information in a lecture, there is little doubt that they would have just believed I was some liberal indoctrinating them with my evolutionary propaganda.

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  8. In reply to Anonymous, regarding sources for evidence for evolution:
    That’s a good question as I too have never found a fully satisfactory single source – i.e. one that is brief and clear and yet also reasonably thorough. There must be one though? I just teach from my notes.

    As for books to which students can be directed, others have recommended to me for this purpose Philip Kitcher’s ‘Abusing Science’ (1982). Recently, I’ve seen good reviews of ‘Why Evolution is True’ by Jerry Coyne, but I’ve not read it myself.

    For what it’s worth, in my class I mention the following. In accordance with the theme of testing and auxiliary assumptions, I also find it useful to spell out how all have ample independent evidence for their own auxiliary assumptions. Given time constraints, there’s not scope for much depth; really, it’s more of a whistlestop tour. Any further suggestions welcome. Anyway:

    -- Imperfect adaptations. Especially that there’s often a clear evolutionary explanation for them. E.g. inefficiency/redundancy of DNA coding for amino acids; human propensity for backache.
    -- Fossils. Especially their pattern of distribution over time and place. Creates a coherent picture of tree of life. No pre-Cambrian rabbits or fossil kangaroos in Canada. Well understood formation process.
    -- Anatomy. Obvious similarities of form (and other traits) between species, and especially that the pattern of relatedness coheres with the history implied by fossils.
    -- Genetics. A great independent test from later 20C – would degrees of genetic relatedness match up with the history earlier implied by fossils and anatomy? Happily, indeed humans are genetically similar to chimps, etc.
    -- Viruses. HIV’s a great example for this – its changing patterns of virulence depending on environment, and its own tree of evolution unfolding in historical time. One source for the HIV story I found usefully chatty (as well as scientifically sound), e.g. including the risqué names of San Francisco bathhouses etc: chapter 1 of Steve Jones’s 2000 book ‘Darwin’s Ghost’.
    Bugs’ development of resistance to drugs is another standby here.
    -- Laboratory. E.g. ability to produce speciation in fruit flies in the lab, as predicted, simply by dividing a single source population then isolating the daughter populations. Only takes 35 generations or so, apparently.
    -- A priori reasoning. Once you have all 3 parts of heritable variation in fitness, for each of which in actual populations there’s overwhelming evidence obviously, the logic is inescapable that natural selection will occur. (Of course, doesn’t mean that’s the only thing that will occur.)

    One nice thing is that it’s not just historical inferences to the best explanation here, but also plenty of manipulations, interventions and predictions.
    I found it also helps to have a passing knowledge of common creationist talking points, e.g. bacterial flagellum, complex eyes, fossil ‘gaps’, how did life first begin, etc.

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  9. Whoops, technical hitch - that last post should have been under my name (i.e. Robert Northcott), not Anna Alexandrova's.

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  10. RE: Anonymous's request for sources on the evidence for evolution.

    The journal Nature has just published a list of "15 Evolutionary Gems" that is freely available at:

    http://www.nature.com/nature/newspdf/evolutiongems.pdf

    It gives 5 examples from fossil records, 5 from habitats, and 5 from molecular processes that show that the principle of natural selection is an empirically validated principle.

    Cheers,
    Colin

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  11. It is interesting that you point out the PBS show. One of the unfortunate things that stood out during the recreated versions of the trial was how poorly argued, from a Phil of Science viewpoint, the case was on the part of the party supporting evolution. Offering simple definitions based on falsification, the lawyer was left merely shaking his head when an ID proponent (Behe?) gave what to many probably sounded as a convicing method for falsifying ID. If at all the video is to serve as an educational tool, it should be offered (it seems to me) as an example of weakly argued Philosophy of Science and also of the shallow understanding of it on the part of scientists.

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