- Examine the merits of evolutionary psychology. Clearly, some of its proponents go too far; does it ever provide us with genuine illumination about certain features of our society or psychology?
- Are Buller and Haufe's criticisms completely fair or is there some way for evolutionary psychologists to respond?
- Does Neander succeed at making room for teleology (proper functions) in a mechanistic world? Evaluate her case.
- Paul Davies argues that the systemic capacity theory of functions actually subsumes selected effects functions — does he succeed?
- Are “malfunctions” impossible? Davies claims so in his paper “Malfunctions” [PDF] (the argument is also sketched in his “The Nature of Natural Norms”). Evaluate this claim.
- Dupré and Kitcher suggest that we ought to be pluralists about natural kinds. Evaluate their arguments.
- What are the prospects for natural kinds essentialism? Does Devitt make a compelling case for recognize at least partly intrinsic essences?
Thursday, February 26, 2009
More Suggested Essay Topics
Here are some further topic ideas you might think about for your first essays. Note that you should not simply think of yourself as answering these questions: you should develop a specific thesis and argue for it carefully, in depth. I am also happy to direct you to further readings on your chosen topic (the Sober collection is generally a good place to start, as is the Sterelny and Griffiths book).
Assingment 7 (due 3/4)
One initially plausible objection to my SPC account of natural kinds concerns the specific notion of stability: doesn't this account imply that there can be no natural kinds of unstable elements? For instance, am I committed to the thesis that Uranium-238 is not a natural kind? Surely this would be a good reason for rejecting my account. Do me a favor and construct a response on my behalf.
If you cannot see that this objection has a good response, try to develop it in the most forceful way you can and explain why you do not believe that a response is possible.
If you cannot see that this objection has a good response, try to develop it in the most forceful way you can and explain why you do not believe that a response is possible.
Meeting 8: A Different Kind of Natural Kind (3/4)
Readings:
The thesis that natural kinds must possess essences, though natural and popular, does not seem to be part of the concept of a natural kind. Their inferential and explanatory role is, to my mind, more central. We’ll focus on a strand of anti-essentialism committed to this stance. Richard Boyd (a philosopher at Cornell) is perhaps the best known defender of anti-essentialism about natural kinds — though I should immediately point out that it is somewhat controversial whether his view should be reckoned as "anti-essentialist" (this is something I'll want to talk about). He defends what he calls a “homeostatic property cluster” (HPC) account of natural kinds on which rather than an essence maintaining the correlation among a bunch of properties we associate with a given kind, the properties, in a way, correlate themselves. No one property among this “cluster” of properties need be regarded as the essence of that kind — they all are. Nor must we view all of the properties as necessarily possessed by members of the HPC kind. The relevant homeostasis may be imperfect, after all.
I find this picture very appealing. But I’m not certain what counts as a homeostatic mechanism and what is meant by certain phrases Boyd uses to cash out this notion: “the causal structure of the world” and so on. This quibble can be answered, I suppose. One answer I can imagine is: “Oh, come on! You know well enough what I mean by ‘the causal structure of the world’! It’s the whole causal economy: the way things work, how everything fits together, what science studies.” But even supposing something like this helped (and I don’t see that it does), a bigger problem for the HPC view is that the kind of homeostasis that Boyd assumes is present is often apparently lacking: say, for higher taxa, species undergoing disruptive selection, or taxa (at the species rank and otherwise) whose coherence is maintained by “phylogenetic inertia”. It seems to me that all we are really committed to with the reality of species is their broad explanatory utility and this can be secured simply by the stability that the relevant cluster of properties features. I defend this thesis in more detail in my “Why the Long Face?” using examples other than species. The paper is a bit on the long side (sorry — this is actually the SHORT version, believe it or not), so you can skim section 2 if pressed for time (you've already heard my views on many of these issues).
Study Questions
- Boyd, “Homeostasis, Species, and Higher Taxa” [PDF]
- Slater, “Why the Long Face? The Stable Property Cluster Account of Natural Kinds” [PDF]
The thesis that natural kinds must possess essences, though natural and popular, does not seem to be part of the concept of a natural kind. Their inferential and explanatory role is, to my mind, more central. We’ll focus on a strand of anti-essentialism committed to this stance. Richard Boyd (a philosopher at Cornell) is perhaps the best known defender of anti-essentialism about natural kinds — though I should immediately point out that it is somewhat controversial whether his view should be reckoned as "anti-essentialist" (this is something I'll want to talk about). He defends what he calls a “homeostatic property cluster” (HPC) account of natural kinds on which rather than an essence maintaining the correlation among a bunch of properties we associate with a given kind, the properties, in a way, correlate themselves. No one property among this “cluster” of properties need be regarded as the essence of that kind — they all are. Nor must we view all of the properties as necessarily possessed by members of the HPC kind. The relevant homeostasis may be imperfect, after all.
I find this picture very appealing. But I’m not certain what counts as a homeostatic mechanism and what is meant by certain phrases Boyd uses to cash out this notion: “the causal structure of the world” and so on. This quibble can be answered, I suppose. One answer I can imagine is: “Oh, come on! You know well enough what I mean by ‘the causal structure of the world’! It’s the whole causal economy: the way things work, how everything fits together, what science studies.” But even supposing something like this helped (and I don’t see that it does), a bigger problem for the HPC view is that the kind of homeostasis that Boyd assumes is present is often apparently lacking: say, for higher taxa, species undergoing disruptive selection, or taxa (at the species rank and otherwise) whose coherence is maintained by “phylogenetic inertia”. It seems to me that all we are really committed to with the reality of species is their broad explanatory utility and this can be secured simply by the stability that the relevant cluster of properties features. I defend this thesis in more detail in my “Why the Long Face?” using examples other than species. The paper is a bit on the long side (sorry — this is actually the SHORT version, believe it or not), so you can skim section 2 if pressed for time (you've already heard my views on many of these issues).
Study Questions
- Briefly describe what an HPC natural kind is. How does it help address the problems facing typological thinking?
- What is Boyd’s accommodation thesis?
- How does the essentialism espoused by Boyd differ from a more “traditional” essentialism about natural kinds?
- What is Boyd’s stance on species pluralism?
- How do explanatory and programmatic definitions differ?
- Does Boyd think that there is an important distinction between species and higher taxa (such as genera)?
- Peacocke draws a distinction between narrow- and wide-scope explanations. Describe it and explain how it is relevant to the discussion of the HPC account.
- Describe a criticism of mine of the HPC view. Do you think Boyd could offer a compelling response?
- What specific problem is posed by disruptive selection?
- What is metastability and how might it be relevant to the discussion of HPC kinds?
- Why is stability important for a potential understanding of natural kinds? What role might it play in such understandings?
- How does the SPC account differ from the HPC account?
Sunday, February 22, 2009
First Half Essay
Remember: I will be recording your first essay score for your best essay I receive by March 11th (in about two and a half weeks!). Remember: you can write as many as you like (and up to two versions of the same essay) and I will only count your best. I strongly recommend you take advantage of this golden opportunity, as I'll be holding you to the high standard expected of a 400/500-level course (according to your specific affiliation).
Specifically, I will be using this rubric to mark your essays. Worry about the tiles of the columns, not the numbers (which will not correspond in the usual way to grades): to get an 'A', you should expect to have most marks in the 'excellent' / 'very good' columns. A 'B' paper will be more centered around the 'very good' column; with 'C', 'D', 'F', as you'd expect. . . . I'll curve numerical scores to reflect this. Bear in mind, however, that as time approaches (if I'm getting lots of submissions at the same time, my ability to turn around the paper quickly for you to revise or rewrite completely will decrease; the sooner you get me something, the more likely it is that you'll be able to revise it into something better)
I highly recommend going through multiple drafts before submitting something. Take account of the writing advice on my website along with the associated links. I can't recommend the "Bennett Rules" — see Bennett and Gorovitz’s essay on “Teaching Academic Writing” — highly enough. Ask yourself honestly whether the paper is as clear and precise as it can be. Write not only so that you can be understood, but so you cannot be misunderstood.
Specifically, I will be using this rubric to mark your essays. Worry about the tiles of the columns, not the numbers (which will not correspond in the usual way to grades): to get an 'A', you should expect to have most marks in the 'excellent' / 'very good' columns. A 'B' paper will be more centered around the 'very good' column; with 'C', 'D', 'F', as you'd expect. . . . I'll curve numerical scores to reflect this. Bear in mind, however, that as time approaches (if I'm getting lots of submissions at the same time, my ability to turn around the paper quickly for you to revise or rewrite completely will decrease; the sooner you get me something, the more likely it is that you'll be able to revise it into something better)
I highly recommend going through multiple drafts before submitting something. Take account of the writing advice on my website along with the associated links. I can't recommend the "Bennett Rules" — see Bennett and Gorovitz’s essay on “Teaching Academic Writing” — highly enough. Ask yourself honestly whether the paper is as clear and precise as it can be. Write not only so that you can be understood, but so you cannot be misunderstood.
Wednesday, February 18, 2009
Assignment 6 (due 2/25)
Pick two of the study questions for Meeting 7 to answer in no more than one sheet total (it may be double-sided).
Meeting 7: Resurrecting Essentialism? (2/25)
Readings:
Michael Devitt has very recently critiqued this consensus as unargued for dogma and presents a new argument in favor of the thesis that biological taxa do in fact possess "at least partly intrinsic" essences. Along the way, he makes a number of important and interesting points worth discussing. Continuing in my critical vein --- you'll have something positive from me at last next week! ---, I argue that Devitt's case for essentialism falls flat. This is not, notice, to argue that essentialism is false --- that's something I want to talk about in more detail with you --- just that we do not yet have good enough reason for being very confident about essentialism.
To foreshadow a later topic a bit, you might give some thought to the role that biological laws play in Devitt's argument. Many philosophers, as you'll see, are deeply skeptical of the idea that there are any distinctively biological laws (let alone laws about particular species). On the other hand, some (like Sandra Mitchell and maybe Marc Lange) hold a view that seems to regard laws as coming in degrees. I'm going to try to write a further section of my paper on how that sort of view might affect the essentialist thesis.
Study Questions
- Okasha, “Darwinian Metaphysics” [PDF] *
- Devitt, “Resurrecting Biological Essentialism” [PDF]
- Slater, “Biological Laws and Essences” [PDF]
Michael Devitt has very recently critiqued this consensus as unargued for dogma and presents a new argument in favor of the thesis that biological taxa do in fact possess "at least partly intrinsic" essences. Along the way, he makes a number of important and interesting points worth discussing. Continuing in my critical vein --- you'll have something positive from me at last next week! ---, I argue that Devitt's case for essentialism falls flat. This is not, notice, to argue that essentialism is false --- that's something I want to talk about in more detail with you --- just that we do not yet have good enough reason for being very confident about essentialism.
To foreshadow a later topic a bit, you might give some thought to the role that biological laws play in Devitt's argument. Many philosophers, as you'll see, are deeply skeptical of the idea that there are any distinctively biological laws (let alone laws about particular species). On the other hand, some (like Sandra Mitchell and maybe Marc Lange) hold a view that seems to regard laws as coming in degrees. I'm going to try to write a further section of my paper on how that sort of view might affect the essentialist thesis.
Study Questions
- What, specifically, do you take Devitt's thesis to be? Try to explain it in detailed, neutral terms.
- Devitt mentions an important distinction between a "taxon problem" and a "category problem": what is this distinction?
- How might the taxon and category problems relate to each other?
- How is the above distinction important to Devitt's argument?
- How does Devitt propose to avoid the anti-essentialism purportedly implied by relational species concepts?
- What are Devitt's two arguments for Essentialism?
- Does Slater miss anything in interpreting these arguments? (No really: do I?)
- Describe (and critically evaluate) Slater's criticism of Devitt's first argument.
- Describe (and critically evaluate) Slater's criticism of Devitt's first argument.
- What is the "Monsters Problem" and how does Devitt respond to it?
Thursday, February 12, 2009
Meeting 6: The Species Problem & the Metaphysics of Species (2/18)
Readings:
In an oft-quoted letter to Joseph Hooker (24 December 1856), Darwin took the difficulty of reaching agreement about a correct conception of species as well-nigh insuperable:
The question What are species? has a different sense. Rather than asking after the conditions under which some organisms belong to a species taxon, we might be interested to know into what ontological category these taxa belong. What is an "ontological category"? This in itself is a somewhat fraught question, but the basic idea is that it is a fundamental category of being: for example, objects, processes, events, properties, sets, numbers, propositions, and so forth might all be considered as such categories. If I ask you What are tables? You might respond by trying to tell me the specific conditions under which some pieces of wood compose a table. Or you might start much more generally by telling me that tables are a certain sort of object, thus distinguishing them from properties or events. Tables and wars are in different ontological categories: the former are objects, the latter are events.
Now then: What sort of thing are species? To what ontological category do they belong? We've already seen some concern about treating species as natural kinds (to some, as certain kinds of sets or classes). Perhaps we should consider an alternative. In this spirit, Michael Ghiselin proposed a "radical solution to the species problem":
The case was taken up by David Hull, an influential philosopher of biology (now emeritus at Northwestern), who offered many reason for treating species as individuals (though it is not always clear what precisely he means by this term). You might think as you’re reading whether his reasons for defending the thesis shed more light on the details of his thesis. What are his reasons? Are the good?
This is where Kitcher’s paper on “Species” picks up: he suggests that Hull fails to offer us good reason for accepting the species-as-individuals (SAI) thesis. Kitcher defends the view that species are certain kinds of sets, arguing that this thesis becomes a straw-man in Hull’s essay. But Kitcher takes the species problem seriously. Perhaps we go wrong to assume that there is just one privileged species concept. But does a plurality of species concepts imply that species are not real? He thinks not. We can be pluralistic realists about species. I suspect that we may want to put this case off for another week or so.
Despite Kitcher's criticisms of Ghiselin and Hull, SAI is more popular than ever. My paper "On the Contentious Metaphysics of Species" critiques some recent arguments for SAI in the context of the early arguments. Of course, even if our criticisms hit their mark, SAI might still be true (don't confuse the truth of a thesis with its pedigree). This is roughly the sense I’ve gotten from many philosophers of biology over the years: "yes, Hull makes an inconclusive case for SAI — but it’s still the best metaphysics of species." Even Kitcher later contended that the issue doesn't bear on anything: one can equally well construe species as individuals or sets. I disagree. My paper "Against the Individuality of Species" makes the case that SAI incurs certain expenses that biologists should not front! As this case is primarily metaphysical (trading in particular on particular theses about ontological vagueness), those non-philosophers of you might find things a bit opaque (hence its being optional). But if you’re interested in getting some further background on vagueness, I can recommend Roy Sorensen’s SEP entry and Achille Varzi’s (2001) article “Vagueness, Logic, and Ontology” (particularly the section on ontological versus semantic vagueness).
Study Questions
- S&D Chapter 9: “Species” **
- Hull, “A Matter of Individuality” [CIEB §18] **
- Kitcher, “Species” [PDF]
- Crane, “On the Metaphysics of Species” [PDF] *
- Slater, “On the Contentious Metaphysics of Species” [PDF]
- Slater, “Against the Individuality of Species” [PDF] **
In an oft-quoted letter to Joseph Hooker (24 December 1856), Darwin took the difficulty of reaching agreement about a correct conception of species as well-nigh insuperable:
It is really laughable to see what different ideas are prominent in various naturalists’ minds when they speak of species; in some, resemblance is everything and descent of little weight — in some, resemblance seems to go for nothing, and Creation the reigning idea — In some, descent is the key, — in some, sterility an unfailing test, with others it is not worth a farthing. It all comes, I believe, from trying to define the indefinable.I think he was too quick to give up, but it’s notable that the same sort of disagreements persist: on one recent count, there were over twenty different species concepts being actively pursued. Is just one of these the correct one? Or perhaps we haven't yet come up with the correct species concept. . . . The issue of whether there is just one privileged conception of species (or biological taxa generally) is often referred to as the debate between "monism" and "pluralism" about species. Kitcher contends that we should be pluralists about species — there is no uniquely correct way of dividing up biological reality. Yet, this doesn't mean that species are not real or that there are objective divisions between different biological groups. So he claims. We'll want to talk about this.
The question What are species? has a different sense. Rather than asking after the conditions under which some organisms belong to a species taxon, we might be interested to know into what ontological category these taxa belong. What is an "ontological category"? This in itself is a somewhat fraught question, but the basic idea is that it is a fundamental category of being: for example, objects, processes, events, properties, sets, numbers, propositions, and so forth might all be considered as such categories. If I ask you What are tables? You might respond by trying to tell me the specific conditions under which some pieces of wood compose a table. Or you might start much more generally by telling me that tables are a certain sort of object, thus distinguishing them from properties or events. Tables and wars are in different ontological categories: the former are objects, the latter are events.
Now then: What sort of thing are species? To what ontological category do they belong? We've already seen some concern about treating species as natural kinds (to some, as certain kinds of sets or classes). Perhaps we should consider an alternative. In this spirit, Michael Ghiselin proposed a "radical solution to the species problem":
It would appear that the philosophy of taxonomy is about to undergo a major upheaval. Symptomatic is its Gordian knot, the species problem. Some years ago (Ghiselin, 1966a) I attempted to cut it with the sword, casually remarking that, in the logical sense, species are individuals, not classes. (1976, 536)The idea seems to be that if we treat species as classes (that is, sets or collections of organisms), we force ourselves into Mayr’s dreaded typological thinking. For the reality of the class would only be secured by some defining essence shared by all (and only) its members. But typology in this sense appears implausible. Perhaps some things have essences (gold, water, electrons, &c.), but the essentialism appears ill-suited to the “blooming, buzzing confusion” of the biological world.
The case was taken up by David Hull, an influential philosopher of biology (now emeritus at Northwestern), who offered many reason for treating species as individuals (though it is not always clear what precisely he means by this term). You might think as you’re reading whether his reasons for defending the thesis shed more light on the details of his thesis. What are his reasons? Are the good?
This is where Kitcher’s paper on “Species” picks up: he suggests that Hull fails to offer us good reason for accepting the species-as-individuals (SAI) thesis. Kitcher defends the view that species are certain kinds of sets, arguing that this thesis becomes a straw-man in Hull’s essay. But Kitcher takes the species problem seriously. Perhaps we go wrong to assume that there is just one privileged species concept. But does a plurality of species concepts imply that species are not real? He thinks not. We can be pluralistic realists about species. I suspect that we may want to put this case off for another week or so.
Despite Kitcher's criticisms of Ghiselin and Hull, SAI is more popular than ever. My paper "On the Contentious Metaphysics of Species" critiques some recent arguments for SAI in the context of the early arguments. Of course, even if our criticisms hit their mark, SAI might still be true (don't confuse the truth of a thesis with its pedigree). This is roughly the sense I’ve gotten from many philosophers of biology over the years: "yes, Hull makes an inconclusive case for SAI — but it’s still the best metaphysics of species." Even Kitcher later contended that the issue doesn't bear on anything: one can equally well construe species as individuals or sets. I disagree. My paper "Against the Individuality of Species" makes the case that SAI incurs certain expenses that biologists should not front! As this case is primarily metaphysical (trading in particular on particular theses about ontological vagueness), those non-philosophers of you might find things a bit opaque (hence its being optional). But if you’re interested in getting some further background on vagueness, I can recommend Roy Sorensen’s SEP entry and Achille Varzi’s (2001) article “Vagueness, Logic, and Ontology” (particularly the section on ontological versus semantic vagueness).
Study Questions
- Explain how the SAI thesis might fit into the debate about typology versus population thinking.
- How does Kitcher’s assertion that “there is no inconsistency in claiming that species are sets and denying that the members of these sets share a common property” (310) answer one of Hull’s arguments for SAI?
- Describe and evaluate Kitcher's arguments for pluralism.
- Explain some objections to the biological species concept.
- Do you think that pluralism is compatible with realism about species?
- Describe Kitcher's lizard example and what it is intended to show.
- What is the difference between historical and structural explanations? How does this distinction bear on the case for pluralism?
- Does pluralism involve the claim that any species concept is acceptable? Why or why not?
- Why is problematic for SAI-ists to adduce the necessary spatiotemporal connectedness of species as evidence for SAI?
- What is Crane's argument for SAI and what difficulties does it face?
Assignment 5 (due 2/18)
Summarize Kitcher's basic argument for species pluralism as carefully and precisely as you can. If space allows, comment on any potential weak points or premises that appear to need further discussion or support.
Thursday, February 5, 2009
Assignment 4 (due 2/11)
(a) Carefully describe the difference between "typological" and "population" thinking.
(b) From what you gather in the Dupré reading, in which camps would you expect Dupré and Putnam to place their allegiances?
(b) From what you gather in the Dupré reading, in which camps would you expect Dupré and Putnam to place their allegiances?
Wednesday, February 4, 2009
Meeting 5: Biological Kinds (2/11)
Required Readings:
The traditional way is by construing some categories (which we call "natural kinds") to be characterized by essential properties — qualities which make things of a particular kind the things of that kind. The late, great biologist (one of the chief architects of the so-called “modern synthesis” of evolutionary biology) Ernst Mayr takes Plato to task for attempting to apply an eidos (something like an abstract type; see CIEB, p. 326) to species. While he’s correct that the notion probably originated with Plato and his theory of forms, it received a much more sophisticated and unmysterious expression with Aristotle. He believed that there was some property (or group of properties) that qualified an organism as the kind of thing it is. Ditto for other examples. Water is a favorite example of modern essentialists like Kripke and Putnam. According to them, the essence of water is having that molecular structure (the one denoted by ‘H2O’); something is water just in case it is composed of H2O and even if that something still looked like and behaved like water. (So goes the thought. My own feeling is that this is much less clear than might at first appear.) However that may be, it was widely thought that species have essences and that this is what makes them real.
But essentialism underpins what Mayr calls "typological thinking". And essentialism may be at the root of many of typology’s supposed ills. Against Aristotle and Plato, I agree with Mayr that we should construe variation as the norm in the biological realm. But there are difficult interpretive questions about what population thinking means for Mayr and how it ought to influence how we conduct and conceive of biology. John Dupré takes on essentialism via Kripke and Putnam's more sophisticated version. He is much exercised by the mismatch between scientific taxonomies and ordinary language classifications.
Study Questions
- Ridley, “Species Concepts and Intraspecific Variation” [Chapter 13 of Evolution; PDF] **
- Slater, "Natural Kinds" [PDF] --- forthcoming! **
- Mayr, “Typological versus Population Thinking” [CIEB §16]
- Sober, “Evolution, Population Thinking, and Essentialism” [CIEB §17] *
- Dupré, "Natural Kinds and Biological Taxa" [PDF]
The traditional way is by construing some categories (which we call "natural kinds") to be characterized by essential properties — qualities which make things of a particular kind the things of that kind. The late, great biologist (one of the chief architects of the so-called “modern synthesis” of evolutionary biology) Ernst Mayr takes Plato to task for attempting to apply an eidos (something like an abstract type; see CIEB, p. 326) to species. While he’s correct that the notion probably originated with Plato and his theory of forms, it received a much more sophisticated and unmysterious expression with Aristotle. He believed that there was some property (or group of properties) that qualified an organism as the kind of thing it is. Ditto for other examples. Water is a favorite example of modern essentialists like Kripke and Putnam. According to them, the essence of water is having that molecular structure (the one denoted by ‘H2O’); something is water just in case it is composed of H2O and even if that something still looked like and behaved like water. (So goes the thought. My own feeling is that this is much less clear than might at first appear.) However that may be, it was widely thought that species have essences and that this is what makes them real.
But essentialism underpins what Mayr calls "typological thinking". And essentialism may be at the root of many of typology’s supposed ills. Against Aristotle and Plato, I agree with Mayr that we should construe variation as the norm in the biological realm. But there are difficult interpretive questions about what population thinking means for Mayr and how it ought to influence how we conduct and conceive of biology. John Dupré takes on essentialism via Kripke and Putnam's more sophisticated version. He is much exercised by the mismatch between scientific taxonomies and ordinary language classifications.
Study Questions
- What is the basic difference between typological and population thinking?
- Mayr argues against the thought that evolutionary gradualism and typological thinking are compatible. Explicate and evaluate this argument.
- What role does Putnam's "Twin Earth" thought experiment play?
- How does Dupré respond to the Twin Earth thought experiment? Are you sympathetic or has Dupré exaggerated the problems?
- What exactly is the worry about the lilies? Is it serious?
- Do you think that taxonomic realism is more or less plausible at higher levels of classification than species? What is Dupré's view on this question? What about Mayr?
- What reasons are there to be pessimistic that the "privileged sameness relations" Putnam seems to need for his theory exist at the level of species?
Wednesday, January 28, 2009
Meeting 4: Functions (2/4)
Required Readings:
The difficulty in biology should now be apparent. If evolutionary theory excises any need for purposes (Aristotelian Final Causes) or intentional design, how can we then attribute function in any normative sense to biological objects? Two answers (or styles of answers) have dominated the literature: etiological (or selected effect) accounts and systemic capacity accounts. The first is represented by Neander’s paper (but was first proposed by Larry Wright) and takes questions about functions as questions about the explanation of a thing’s existence. To ask what the function of the human heart is, on this account, is to ask in virtue of doing what is the heart possessed by humans. It’s in virtue of the pumping action of hearts (and not, say, the pumping noises they make) that their possessors have prospered. So natural selection, on this view, gives us the sense of normativity which we pretheoretically attribute to (proper) functions.
Not everyone is convinced by this general account. Lots of questions arise here. Is the etiological theory a general account of function (Wright’s version appears to be) or is it only applicable in the biological world? Is it meant as a conceptual analysis of the notion of function? Does it suppose that traits evolved carrying out the function that they now have — can the etiologist make sense of Gould and Vrba’s exaptations? Partly in response to difficulties like these, many philosophers have turned to a more liberal causal role (or systemic capacity) account of function which abjures reference to history (selective or otherwise) in favor of what Cummins called functional analysis. On this systemic capacity view, a trait’s function(s) are just whatever causal capacities that trait contributes to a system. On this view, the “normativity” of function wanes, as the number of distinct functions skyrockets. We may still be able to make sense of the function of the heart to pump blood and not make pumping sounds, in virtue of the fact that the former (but not the latter) activity contributes to the performance of the system in which hearts are embedded.
Davies defends this systemic capacity approach, arguing that it actually subsumes the etiological approach. For an excellent (obviously opinionated) background on the different theories and how they compare, you might consider reading his essay first and then circling back to Neander’s.
Study Questions
- Godfrey-Smith, "Functions: Consensus without Unity" [PDF]
- Neander, "Functions as Selected Effects: The Conceptual Analyst's Defense" [PDF]
- Davies, "The Nature of Natural Norms: Why Selected Functions are Systemic Capacity Functions" [PDF]
The difficulty in biology should now be apparent. If evolutionary theory excises any need for purposes (Aristotelian Final Causes) or intentional design, how can we then attribute function in any normative sense to biological objects? Two answers (or styles of answers) have dominated the literature: etiological (or selected effect) accounts and systemic capacity accounts. The first is represented by Neander’s paper (but was first proposed by Larry Wright) and takes questions about functions as questions about the explanation of a thing’s existence. To ask what the function of the human heart is, on this account, is to ask in virtue of doing what is the heart possessed by humans. It’s in virtue of the pumping action of hearts (and not, say, the pumping noises they make) that their possessors have prospered. So natural selection, on this view, gives us the sense of normativity which we pretheoretically attribute to (proper) functions.
Not everyone is convinced by this general account. Lots of questions arise here. Is the etiological theory a general account of function (Wright’s version appears to be) or is it only applicable in the biological world? Is it meant as a conceptual analysis of the notion of function? Does it suppose that traits evolved carrying out the function that they now have — can the etiologist make sense of Gould and Vrba’s exaptations? Partly in response to difficulties like these, many philosophers have turned to a more liberal causal role (or systemic capacity) account of function which abjures reference to history (selective or otherwise) in favor of what Cummins called functional analysis. On this systemic capacity view, a trait’s function(s) are just whatever causal capacities that trait contributes to a system. On this view, the “normativity” of function wanes, as the number of distinct functions skyrockets. We may still be able to make sense of the function of the heart to pump blood and not make pumping sounds, in virtue of the fact that the former (but not the latter) activity contributes to the performance of the system in which hearts are embedded.
Davies defends this systemic capacity approach, arguing that it actually subsumes the etiological approach. For an excellent (obviously opinionated) background on the different theories and how they compare, you might consider reading his essay first and then circling back to Neander’s.
Study Questions
- Godfrey-Smith proposes that we should understand functions as effects that have led to a trait's being preserved or proliferated through recent episodes of natural selection. Does this effectively deal with the difficulties facing the etiological approach?
- Describe some prima facie differences in the explanatory aims between the systemic capacity account of functions and the selected effect account.
- Neander mentions three objections to the etiological theory of proper functions. Briefly describe them.
- Neander writes that it is “indeed the vague, unifying, everyday notion of a ‘proper function’ from which the biological notion is derived. Nonetheless, the peculiarities of natural selection impose certain constraints upon a more detailed and precise analysis of the biological notion, . . . constraints which do not apply to the everyday notion employed by artifacts” (175). How does this fit in with her take on the role of conceptual analysis in contrast to theoretical definition.
- What do you think of Neander’s response to the “intellectual arrogance” objection?
- How does Neander propose to deal with the “instant winged lions”? Do you find this a satisfactory response to the problem?
- Briefly describe Neander’s cancer objection to the causal role theory. Does Davies have a credible response?
- What is Davies’ argument that systemic capacity functions have a broader range of application than do selected functions? Does it seem sound?
- Does Davies believe that there are selected functions?
- Why does Davies object to natural norms?
- Why does Godfrey-Smith think that Kitcher is wrong to seek unity in different accounts of function?
Assignment 3 (due 2/4)
Neander discusses three objections to the selected effects view of functions. Choose one to discuss. Carefully explain what the objection is and critically discuss how Neander purports to solve it.
Wednesday, January 21, 2009
Assignment 2 (due on 1/28)
Pick three of the study questions for Meeting 3 to answer in no more than one sheet total (it may be double-sided).
Meeting 3: Sociobiology & Evolutionary Psychology (1/28)
Required Readings:
Evolutionary psychology billed itself as the grown-up, fixed-up, and focused version of essentially the same program: integrating evolutionary biology with human psychology. One of the central battlegrounds of this debate concerns our cognitive architecture: is the mind a sort of all-purpose, plastic computer or is it (as many influential evolutionary psychologists suppose) a conglomeration of domain-specific modules? If the latter, presumably, our evolutionary history as foraging primates ought to shed some light on certain features of our psychology now. After all, recorded history represents a rather small portion of hominid history.
I am extremely skeptical about much of evolutionary psychology. So are Buller and Haufe. As you probably know, skepticism is ambiguous: it can mean either disbelief or suspension of belief. Both seem appropriate. Some of the empirical claims of evolutionary psychologists seem to be false; other claims simply lack adequate support. And yet, there is something undeniably attractive about evolutionary psychology as a general strategy, as perhaps, there is with certain forms of adaptationism. The challenge, then, would seem to be how to separate the wheat from the chaff. What if anything can our evolutionary history tell us about ourselves?
Study Questions
- Tooby and Cosmides, "Toward Mapping the Evolved Functional Organization of Mind and Brain" [CIEB §9]
- Buller, "Evolutionary Psychology: A Critique" [CIEB §10]
- Haufe, "Perverse Engineering" [PDF]
- S&D, Chapters 13-14 **
Evolutionary psychology billed itself as the grown-up, fixed-up, and focused version of essentially the same program: integrating evolutionary biology with human psychology. One of the central battlegrounds of this debate concerns our cognitive architecture: is the mind a sort of all-purpose, plastic computer or is it (as many influential evolutionary psychologists suppose) a conglomeration of domain-specific modules? If the latter, presumably, our evolutionary history as foraging primates ought to shed some light on certain features of our psychology now. After all, recorded history represents a rather small portion of hominid history.
I am extremely skeptical about much of evolutionary psychology. So are Buller and Haufe. As you probably know, skepticism is ambiguous: it can mean either disbelief or suspension of belief. Both seem appropriate. Some of the empirical claims of evolutionary psychologists seem to be false; other claims simply lack adequate support. And yet, there is something undeniably attractive about evolutionary psychology as a general strategy, as perhaps, there is with certain forms of adaptationism. The challenge, then, would seem to be how to separate the wheat from the chaff. What if anything can our evolutionary history tell us about ourselves?
Study Questions
- What concerns about sociobiology (as described in the *optional* S&D reading) seem to you most pressing? What about for evolutionary psychology?
- What do you think of Tooby and Cosmides’ claim that the human brain is adapted to the hunting-gathering lifestyle of our Pleistocene forebears?
- Tooby and Cosmides claim that understanding human neural architecture is “a problem in reverse engineering” (184). What, specifically, does this entail?
- Haufe claims that the method of reverse engineering (RE) in evolutionary biology faces some deep conceptual difficulties. What are these difficulties? What empirical difficulties does RE face?
- What are the experiments with the Watson selection task supposed to show about the "modularity" of the mind? Why does Buller believe that they fail to show this?
- Evolutionary psychologists have argued that domain-general cognitive mechanisms, insofar as they are (or would have been) maladaptive, are impossible. Why is this claim false?
- It has been alleged that evolutionary psychology (like sociobiology) involves a heavy does of adaptationism. What kind(s) of adaptationism would you suppose this to be and why?
- What significance does the possibility of genetic drift have in discussions of evolutionary psychology?
Tuesday, January 20, 2009
Toxic Newts!
I came across this video (from a PBS program) a while ago that presents a lovely example of how "evolutionary arms races" can produce dramatic adaptations. Fun stuff!
Thursday, January 15, 2009
Course Requirements & Policies
Now you can recycle your paper syllabi. This post will be your reference for how I will assess your learning in this course.
Attendance & Participation (10%). This should be obvious: you should come to every class meeting (especially for a one-a-week class). After one missed class, each further unexcused absence will reduce your final grade by three percentage points; more than four unexcused absences will mean an automatic failure (you can’t miss a whole quarter of the course and expect to pass — this is not a “skills course”). If you must miss a class (and I’ll be the judge of ‘must’), you should contact me before the class in question (unless circumstances make this impossible for some strange reason — I’ll be the judge of ‘impossible’ as well); missed presentations will be scored a zero and will not be dropped (see below). Earning an ‘A’ for this section of the course will require being an involved and helpful participant (raising questions and engaging in the discussion without dominating it) in the vast majority of our meetings. Simply attending and at looking attentive will get you at most a ‘C’ for participation.
Weekly Assignments (15%). Each week, you will write one sheet in response to a question (or a series of questions) concerning the reading. These will be due at the beginning of class and be evaluated on a 0–4 scale (0=“not done”/“wildly insufficient”, 1=“needs improvement”, 2=“acceptable”, 3=“good”, 4=“excellent!”). While no extensions will be granted for any reason (“legitimate” or otherwise), I will drop your lowest three marks. At the end of the course, I will sum your remaining scores and curve the result so that an average of ‘3’ comes out to a B+.
Impromptu Presentations (20%). Unless you are giving a formal presentation in a certain class (see below), you will be on call to give a short, “impromptu” presentation on a topic of my choosing (generally selected from the study questions I make available on the website or from the weekly reaction paper topic). These will be random. I have a 20-sided die, you’ll each get a number. If your number gets rolled, you’ll speak to us for five or so minutes. I’ll let you punt twice (i.e., you can say, “um, I’d rather not do one of these now” without penalty — but only if you’re there to say it!). These will be scored on that 0–4 scale; I’ll drop the worst non-zero score, and average together the rest and curve the result around a B+.
Short Essay (15%). A short essay (1,500–2,000 words for undergraduates, 2,000–3,000 words for graduates) is due by March 11th at 3:30PM. I will not assign paper topics (though I can give you some suggestions if you’re stuck). Instead, I invite you to write on (subject to my approval) whatever you’re finding most interesting in the course and turn it in whenever you have the opportunity. What’s more, you may submit multiple essays (up to one per week, including at most one rewrite of the same essay) and only your best will count toward this grade category. Since you have all the time in the world to adjust your schedules, late essays will be dealt with rather harshly: late essays will be docked five percentage points per partial day late — e.g., you get a 82% on an essay submitted one hour late; it receives a 77%).
Formal Presentation (10%) & Response (5%). Toward the second half of the term, we will start doing formal in-class presentations of the sort that one would see in a professional academic conference. You will be presenting an original research paper on a topic in the neighborhood of the topic scheduled for class that day. These presentations will run from 10–15 minutes and will be based on a 1,500–2,000 word essay. Each presentation will be assigned a commentator who will offer a five minute commentary after which the speaker will be permitted a brief reply. At this point, we will open up the discussion to the group. You should start thinking early about when you’d like to present and when you’d be willing to comment. Commentators and I should receive the paper by the weekend before the presentation is scheduled.
Final Essay (25%). Your final essay (2,000–3,000 words for undergraduates, 3,000–5,000 words for graduates) will be based on your presentation and should incorporate the feedback you receive on that occasion. These will be due by May 11th at 3:30PM.
I have high expectations of you: that you read everything carefully, that you actively engage with the discussion, that you stringently observe a no-bullshit-policy, and that you complete work on time. But you should have high expectations of me as well. I am very often available outside of class to help you understand course material. I’m happy to read drafts, discuss questions/issues, and help you sort out your thoughts as best I can. If I’m in my office and distractable (as I often am), I’ll try to set my IM status to “Available” (my IM handle is ‘mslater@uidaho.edu’)
Texts:
Sober (Ed.), Conceptual Issues in Evolutionary Biology, 3rd Ed. (MIT, 2006)
Lewontin, The Triple Helix (Harvard, 2000)
Other articles provided in PDF format on the Blackboard website.
The interests of trees and our learning sometimes conflict. Please do what you can to minimize paper waste (use recycled paper, reclaimed paper, &c.; printing the articles two-up, double-sided in Acrobat is usually possible), but please bring copies of the relevant articles to our meetings (on a laptop is fine), as we will often need to read them closely together.
Optional Text: Griffiths and Sterelny, Sex and Death (UChicago, 1999)
This book (referred to as ‘S&D’ in the schedule) is a fairly comprehensive introduction to the philosophy of biology. Several of its chapters provide useful background to the issues we’ll be dealing with; many chapters take on different topics that we won’t get to. If you’re interested in reading more in the philosophy of biology, it’s a great book to have on your shelf.
Attendance & Participation (10%). This should be obvious: you should come to every class meeting (especially for a one-a-week class). After one missed class, each further unexcused absence will reduce your final grade by three percentage points; more than four unexcused absences will mean an automatic failure (you can’t miss a whole quarter of the course and expect to pass — this is not a “skills course”). If you must miss a class (and I’ll be the judge of ‘must’), you should contact me before the class in question (unless circumstances make this impossible for some strange reason — I’ll be the judge of ‘impossible’ as well); missed presentations will be scored a zero and will not be dropped (see below). Earning an ‘A’ for this section of the course will require being an involved and helpful participant (raising questions and engaging in the discussion without dominating it) in the vast majority of our meetings. Simply attending and at looking attentive will get you at most a ‘C’ for participation.
Weekly Assignments (15%). Each week, you will write one sheet in response to a question (or a series of questions) concerning the reading. These will be due at the beginning of class and be evaluated on a 0–4 scale (0=“not done”/“wildly insufficient”, 1=“needs improvement”, 2=“acceptable”, 3=“good”, 4=“excellent!”). While no extensions will be granted for any reason (“legitimate” or otherwise), I will drop your lowest three marks. At the end of the course, I will sum your remaining scores and curve the result so that an average of ‘3’ comes out to a B+.
Impromptu Presentations (20%). Unless you are giving a formal presentation in a certain class (see below), you will be on call to give a short, “impromptu” presentation on a topic of my choosing (generally selected from the study questions I make available on the website or from the weekly reaction paper topic). These will be random. I have a 20-sided die, you’ll each get a number. If your number gets rolled, you’ll speak to us for five or so minutes. I’ll let you punt twice (i.e., you can say, “um, I’d rather not do one of these now” without penalty — but only if you’re there to say it!). These will be scored on that 0–4 scale; I’ll drop the worst non-zero score, and average together the rest and curve the result around a B+.
Short Essay (15%). A short essay (1,500–2,000 words for undergraduates, 2,000–3,000 words for graduates) is due by March 11th at 3:30PM. I will not assign paper topics (though I can give you some suggestions if you’re stuck). Instead, I invite you to write on (subject to my approval) whatever you’re finding most interesting in the course and turn it in whenever you have the opportunity. What’s more, you may submit multiple essays (up to one per week, including at most one rewrite of the same essay) and only your best will count toward this grade category. Since you have all the time in the world to adjust your schedules, late essays will be dealt with rather harshly: late essays will be docked five percentage points per partial day late — e.g., you get a 82% on an essay submitted one hour late; it receives a 77%).
Formal Presentation (10%) & Response (5%). Toward the second half of the term, we will start doing formal in-class presentations of the sort that one would see in a professional academic conference. You will be presenting an original research paper on a topic in the neighborhood of the topic scheduled for class that day. These presentations will run from 10–15 minutes and will be based on a 1,500–2,000 word essay. Each presentation will be assigned a commentator who will offer a five minute commentary after which the speaker will be permitted a brief reply. At this point, we will open up the discussion to the group. You should start thinking early about when you’d like to present and when you’d be willing to comment. Commentators and I should receive the paper by the weekend before the presentation is scheduled.
Final Essay (25%). Your final essay (2,000–3,000 words for undergraduates, 3,000–5,000 words for graduates) will be based on your presentation and should incorporate the feedback you receive on that occasion. These will be due by May 11th at 3:30PM.
I have high expectations of you: that you read everything carefully, that you actively engage with the discussion, that you stringently observe a no-bullshit-policy, and that you complete work on time. But you should have high expectations of me as well. I am very often available outside of class to help you understand course material. I’m happy to read drafts, discuss questions/issues, and help you sort out your thoughts as best I can. If I’m in my office and distractable (as I often am), I’ll try to set my IM status to “Available” (my IM handle is ‘mslater@uidaho.edu’)
Texts:
Sober (Ed.), Conceptual Issues in Evolutionary Biology, 3rd Ed. (MIT, 2006)
Lewontin, The Triple Helix (Harvard, 2000)
Other articles provided in PDF format on the Blackboard website.
The interests of trees and our learning sometimes conflict. Please do what you can to minimize paper waste (use recycled paper, reclaimed paper, &c.; printing the articles two-up, double-sided in Acrobat is usually possible), but please bring copies of the relevant articles to our meetings (on a laptop is fine), as we will often need to read them closely together.
Optional Text: Griffiths and Sterelny, Sex and Death (UChicago, 1999)
This book (referred to as ‘S&D’ in the schedule) is a fairly comprehensive introduction to the philosophy of biology. Several of its chapters provide useful background to the issues we’ll be dealing with; many chapters take on different topics that we won’t get to. If you’re interested in reading more in the philosophy of biology, it’s a great book to have on your shelf.
Wednesday, January 14, 2009
Meeting 2: Fitness and Adaptation (1/21)
Required Readings: (I recommend going in this order). Remember that starred items are required for grad students, but optional for undergrads; and double-starred items are optional for everyone and that 'CIEB' denotes the Sober collection Conceptual Issues in Evolutionary Biology.
We'll address two important issues for the interpretation of evolutionary biology this week: the status of Darwinian claims about fitness (captured in such well-known slogans as "the survival of the fittest") and the concept of adaptation and adaptationist thinking.
As I mentioned today, Karl Popper was deeply influential in the philosophy of science through much of the 20th century. His criterion of science — "falsifiability" — stipulated that in order for a theory to be judged as "scientific", a theory must be subjected to "severe tests". There must be experiments you could run or observations you could make that would show the theory to be false. That's a bad criterion of science for several reasons. Suffice it to say, that many perfectly legitimate theories have not been cast away on the basis of a surprising observation. As Kuhn put it, it's a bad carpenter who blames his tools. I might say more about this next time.
Nevertheless, the idea that science should be falsifiable continues to exert a great deal of influence. Perhaps there's some good reason for this. Unfalsifiability may bespeak other theoretical vices, like circularity. This is roughly the charge Mills and Beatty are concerned to rebut in their article on fitness. As we know, differential fitness is required for natural selection to drive evolution. But what is fitness? How is it defined? Not by "burliness" or "speed" or even being adapted to some environment. What matters is reproduction. It's tempting to understand fitness as a measure of how many descendants an individual leaves behind. But then it's no surprise that the fittest survive to reproduce: for fitness is defined as survival to reproduce! Thus, Darwin's theory is circular and not truly scientific. The basic idea behind Mills and Beatty's approach is that 'fitness' in evolutionary theory can be understood in at least two different ways: fitness of an organism and fitness of a type, and that we should construe each of these claims as claims about propensities to reproduce, rather than actual reproductive performance. (Don't worry about trying to understand the example on p. 16 of CIEB in detail — I'll run through it.)
Another source of concern about Darwin's theory is that it is merely a series of promissory notes — that it doesn't actually explain anything, but merely suggests that some evolutionary story or other is tellable. Kitcher effectively responds to this general charge in connection to the falsifiability concern in his "Darwin's Achievement" (which is certainly worth a look if you have the time). But there remains an influential strand of evolutionary thinking which Stephen Jay Gould and Richard Lewontin famously dubbed "The Adaptationist Program" and lampooned in the spirit of Voltaire: that any trait can be explained by being adaptive (by contributing to the fitness of the organisms which possess it). The ability to tell some unfalsifiable "just-so" story doesn't really explain anything! One of the interesting issues here is whether Gould and Lewontin go too far in their rejection of adaptationist thinking: whether there isn't something to adaptationist thinking.
Dennett thinks so. He offers a refreshingly frank admission of his longing to believe evolutionary stories involving avian honey guides and aquatic apes. . . . Is he just offering an optimistic counterpoint to Gould and Lewontin? Perhaps since, as Dobzhansky put it "nothing in biology makes sense except in the light of evolution", some evolutionary story or other has to be behind various adaptations we shouldn't be too worried about indulging in adaptationist reasoning. The Dennett vs. Gould/Lewontin debate is something we should talk a bit about.
Gould and Elisabeth Vrba, a few years after Gould and Lewontin wrote their influential critique of adaptationism, offered an important concept that illustrates a worry with Dennett's optimistic approach. Because some trait is adaptive does not necessarily mean that its prevalence owes to its having been adaptive in that way (this distinction will loom large in our discussion of biological function in a few weeks). Feathers may be a good example: did they arise and proliferate because they were good for flying or because they were good for other things and then get co-opted for flight? Gould and Vrba want to call this an "exaptation".
Study Questions
- Mills & Beatty, “The Propensity Interpretation of Fitness” [CIEB §1]
- Sober, “The Two Faces of Fitness” [CIEB §2] **
- Gould & Lewontin, “The Spandrels of San Marco and the Panglossian Paradigm” [CIEB §5]
- Gould & Vrba, “Exaptation: a Missing Term in the Science of Form” [PDF]
- Dennett, “The Leibnizian Paradigm” [PDF] *
- S&D: Chapter 10: “Adaptation, Perfection, Function” **
We'll address two important issues for the interpretation of evolutionary biology this week: the status of Darwinian claims about fitness (captured in such well-known slogans as "the survival of the fittest") and the concept of adaptation and adaptationist thinking.
As I mentioned today, Karl Popper was deeply influential in the philosophy of science through much of the 20th century. His criterion of science — "falsifiability" — stipulated that in order for a theory to be judged as "scientific", a theory must be subjected to "severe tests". There must be experiments you could run or observations you could make that would show the theory to be false. That's a bad criterion of science for several reasons. Suffice it to say, that many perfectly legitimate theories have not been cast away on the basis of a surprising observation. As Kuhn put it, it's a bad carpenter who blames his tools. I might say more about this next time.
Nevertheless, the idea that science should be falsifiable continues to exert a great deal of influence. Perhaps there's some good reason for this. Unfalsifiability may bespeak other theoretical vices, like circularity. This is roughly the charge Mills and Beatty are concerned to rebut in their article on fitness. As we know, differential fitness is required for natural selection to drive evolution. But what is fitness? How is it defined? Not by "burliness" or "speed" or even being adapted to some environment. What matters is reproduction. It's tempting to understand fitness as a measure of how many descendants an individual leaves behind. But then it's no surprise that the fittest survive to reproduce: for fitness is defined as survival to reproduce! Thus, Darwin's theory is circular and not truly scientific. The basic idea behind Mills and Beatty's approach is that 'fitness' in evolutionary theory can be understood in at least two different ways: fitness of an organism and fitness of a type, and that we should construe each of these claims as claims about propensities to reproduce, rather than actual reproductive performance. (Don't worry about trying to understand the example on p. 16 of CIEB in detail — I'll run through it.)
Another source of concern about Darwin's theory is that it is merely a series of promissory notes — that it doesn't actually explain anything, but merely suggests that some evolutionary story or other is tellable. Kitcher effectively responds to this general charge in connection to the falsifiability concern in his "Darwin's Achievement" (which is certainly worth a look if you have the time). But there remains an influential strand of evolutionary thinking which Stephen Jay Gould and Richard Lewontin famously dubbed "The Adaptationist Program" and lampooned in the spirit of Voltaire: that any trait can be explained by being adaptive (by contributing to the fitness of the organisms which possess it). The ability to tell some unfalsifiable "just-so" story doesn't really explain anything! One of the interesting issues here is whether Gould and Lewontin go too far in their rejection of adaptationist thinking: whether there isn't something to adaptationist thinking.
Dennett thinks so. He offers a refreshingly frank admission of his longing to believe evolutionary stories involving avian honey guides and aquatic apes. . . . Is he just offering an optimistic counterpoint to Gould and Lewontin? Perhaps since, as Dobzhansky put it "nothing in biology makes sense except in the light of evolution", some evolutionary story or other has to be behind various adaptations we shouldn't be too worried about indulging in adaptationist reasoning. The Dennett vs. Gould/Lewontin debate is something we should talk a bit about.
Gould and Elisabeth Vrba, a few years after Gould and Lewontin wrote their influential critique of adaptationism, offered an important concept that illustrates a worry with Dennett's optimistic approach. Because some trait is adaptive does not necessarily mean that its prevalence owes to its having been adaptive in that way (this distinction will loom large in our discussion of biological function in a few weeks). Feathers may be a good example: did they arise and proliferate because they were good for flying or because they were good for other things and then get co-opted for flight? Gould and Vrba want to call this an "exaptation".
Study Questions
- You might think about these questions as plausible targets for your impromptu presentations.
- What is a propensity?
- What is the difference between fitness as actual reproductive success and fitness as a “propensity”?
- Explain how understanding fitness as a propensity relieves the circularity problem discussed in Mills and Beatty.
- Mills and Beatty distinguish between the fitness of individual organisms and the fitness of types. What is the difference? Why do they write that fitness of types cannot be a propensity?
- What is an adaptation?
- What is the adaptationist program according to Gould and Lewontin? What’s wrong with it (according to them)?
- What challenges do the adaptationists face in dividing organisms up into traits (according to Gould and Lewontin)?
- Why think that the adaptationist program is unfalsifiable?
- What is “exaptation”?
- What is a “Bauplan”? How does it fit into the debate about adaptationism?
Assignment 1 (due 2/21)
Please write no more than one sheet (two-sides if you must) in response to the following questions. Be succinct but complete. Strive for clarity and detail, keeping your prose as simple as possible.
1) What, precisely, is the circularity worry that many believe Darwin's theory faces? Summarize it and how Mills and Beatty purport to solve it.
2) Describe the difference between 'adaptation' and 'exaptation'.
1) What, precisely, is the circularity worry that many believe Darwin's theory faces? Summarize it and how Mills and Beatty purport to solve it.
2) Describe the difference between 'adaptation' and 'exaptation'.
Thursday, January 8, 2009
Meeting 1: Introduction
First meetings of courses are often short, trivial occasions. I see no reason why ours must be. We'll begin by discussing the structure of Darwin's theory, its origin and subsequent elaboration in the context of improved genetic knowledge, and how it has been confirmed to such a dramatic extent. This will put us in a position to begin to address the conceptual questions about evolutionary biology which will detain us for the bulk of the course.
I hope you'll have a chance to read some of the following as background to our discussion. To access these, you will need to log in to Blackboard (if you're registered in the course, you should have access to the blackboard page now --- or you will shortly). If you have not yet registered or are a WSU student, please send me an email and I'll send you a link from which you can download them.
Optional/Recommended Reading:
I hope you'll have a chance to read some of the following as background to our discussion. To access these, you will need to log in to Blackboard (if you're registered in the course, you should have access to the blackboard page now --- or you will shortly). If you have not yet registered or are a WSU student, please send me an email and I'll send you a link from which you can download them.
Optional/Recommended Reading:
- Mayr, chapter 2 and chapter 6 of One Long Argument
- Kitcher, "Darwin's Achievement"
- Ridley, chapter 4 of Evolution: this chapter on variation and natural selection may be useful reading for those who feel a bit shaky about their biological background.
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