Somethings you might enjoy

I read a blog managed by Massimo Pigliucci called Scientia Salon. He posts himself and carries interesting stuff on the current evo biology that I find informative.  At any rate he has recently posted two things that you might enjoy.

First, there is this piece on the Formal Darwinism Project. The aim seems to be to provide a rational basis for the kind of teleological/functional/good design thinking that evo theorists find so compelling (and, it appears given the paper, they find it so for some good reasons). Of course, such thinking is hardly foolproof and there are lots of times when it fails. The idea seems to be to ground it and see where it works and where not. Interestingly, part of the effort is to find those circumstances in which not knowing much about the genetics won't make much of a difference.  This is where the "phenotypic gambit" works. Here's the author:

In 1984, I coined the term ‘Phenotypic Gambit’ for the research strategy of studying organisms in ignorance of the actual genetic architecture of the trait in question … The Phenotypic Gambit articulates the assumption that is usually made implicitly in this work, and the formal darwinism project aims to understand better why and how the gambit works when it does, and also to identify and understand those cases in which the gambit fails.

Interestingly, it seems that much (indeed, it seems, most) work in evolutionary is done in complete and utter ignorance of the relevant genetics, on the assumption that in many cases "the genetic details, which aren't known, are unlikely to matter" (quote from paper post links to. It's behind a paywall, but many can get it through their university libraries). Here's another quote from Jarrold Hadfield (170):

If you exclude simple Mendelian traits…then we know very little about the genetic basis of most traits.

Why do I mention this? Well, there is a huge amount of skepticism regarding Darwin's Problem. Some of this stems from the fact that we know little about the genetics underlying language so that thinking about it is just so much hand waving. This was a theme at the Athens conference (in fact, I might have been the one person there who did not buy into this) and it was also a theme discussed on this blog here. However, if this article is right, then it seems that it is a problem way beyond anything having to do with DP as applied to FL. It is very very common in evo investigations. And if it is ok for people studying stuff in animals to make the Phenotypic Gambit (as a useful idealization and always ready to retreat when it proves wrong) then why not in the study of FL/UG as well.

In our case, the gambit amounts to assuming that a "simple" phenotypic description will translate into a simple genetic one. This may be wrong, but it seems to be widely adopted despite the obvious problems. In short, it seems that perhaps (see the hedging here) those interested in DP are doing exactly what the state of the evo art recommends: do the best you can given that we know little about the genetics of anything bigger than bacteria. At the very least, the phenotypic gambit, the assumption that the genetics, once understood, will not greatly distort the conclusions drawn from phenotypic reasoning, is both widespread in biology and useful. Of course, maybe these people aren't doing real biology either. Maybe.

Second, there is this provocative post by Pigliucci in funding for science research. He points out that the question of why society should fund pure science is one that needs to be seriously addressed. Moreover, the standard arguments seem to lack much serious empirical grounding once one gets beyond anecdote.  Linguists should think this question through given that more and more of our work is being supported by gvmt grants or foundations. Why should they fund it?  The argument that one day it will help us cure cancer is not that compelling. What is more compelling is that I actually no of virtually no interesting applied (aka translational) work that does not rely on huge amounts of work funded for less instrumental ends.  In other words, from the little I know, most translational research presupposes results gained from publicly funded efforts. The results are easy enough to spot all around us today. The  last breakthroughs are almost always based on gvmt sponsored work (think internet, iPhone, computer, most of current molecular biology etc.). As I noted sometime ago, the computer would not exist but for the work of logicians interested in the foundation of mathematics. The fact is that most of the wonders around us hail from curiosity driven research. And what is also clear is that the fruits of this work would have been virtually impossible to anticipate ex ante.

Pigliucci touches on one other theme that is noteworthy: the bullshittification of grant applications when the one needs to defend ones work in purely instrumental terms. His observations quoted here fit well with my own:

When I was submitting grant proposals to NSF, I was required to also fill out a section about the “broader impact” of my research (which was on genotype-environment interactions in a species of weedy plants). It was always an afterthought, a boilerplate that got copied from proposal to proposal. And so were those of most of my colleagues. The reason is that — even though I was actually studying something for which practical applications were not at all far fetched (e.g., weed control, invasive biology), that’s not why I was doing it. I was doing it because I had a genuine basic curiosity about the science involved. Indeed, had NSF really only funded basic research that had a direct link to applications I could have done pretty much the same thing on a different model system, say a weed or an invasive species with well demonstrated commercial effects. And mine was by far not even close to being the most narrowly focused and idiosyncratic piece of science carried out within my own department, let alone in the US at large.

At any rate, the piece raises important issues: why should anyone fund our work? Why should they care? Here we need to be able to elaborate what we do for a wider audience in terms that they can understand. I've discussed this before (here). Pigliucci's discussion pushes the question further. It is not unreasonable for people to ask why we should keep paying. One answer is that the problems we try to investigate are intrinsically interesting. I believe that this is right. And I have a spiel. Do you? If not, get one!

Turing and Chomsky

There are two observations that motivate the Minimalist Project. 

The first is that the emergence of FL is a rather recent phenomenon biologically, say roughly 50-100kya. The argument based on this observation is that ifbiological complexity is a function of natural selection (NS) and NS is gradual then given the observation that language biologically arose “merely” 50-100kya implies whatever arose could not have been particularly complex. Why? Because complexity would require shaping by slow selection pressures and 50-100,000 years is not enough time to shape anything very complex. That’s the argument. And it relies, ahem, on many assumptions, not all of them at all obvious.

First, why think that 50-100,000 years is not enough time to develop a complex cognitive organ? Maybe that’s a lot of time. Second, how do we measure complexity? Biology selects genes, but MP measures complexity wrt the simplicity of the principles of FL/UG. Why assume that the phenotypic simplicity of linguistic descriptions of FL/UG line up well with the simplicity of the genetic foundations that express these phenotypic traits?[1]

This second problem is, in fact, not unique to EvoLang. It is part and parcel of the “phenotypic gambit” that I discussed elsewhere (here). Nonetheless, the fact that this is a generalissue in Evo accounts does not mean it is not also a problem for MP arguments. Third, every time one picks up the papers nowadays one reads that someone is arguing that language emerged further and further back. Apparently, many believe that Neanderthals jabbered as much as we did and if this is the case we push back the emergence of language many 100,000s of years. Of course, we have no idea what such language consisted in even if it existed (did it have an FL like ours?), but there is no question that were this fact established (and it is currently considered admissible I am told) then the simple minded argument noted above becomes less persuasive.

All in all then, the first kind of Evo motivation for a simpler FL/UG, though not nothing, is not particularly dispositive (some might even think it downright weak (and we might not be able to strongly rebut this churlish skepticism)). 

But there is a second argument, and I would like to spotlight it here. The second argument is that wheneverit arose it has remained stable since its inception. In other words, FL/UG has been conserved in the species since it arose. How do we know this? Well, largely because any human kid can learn any human language in effectively the same way if prompted by the relevant linguistic input. We should be very surprised that this is so if indeed FL/UG is a very complex system that slowly arose via NS. Why? Because if it did so slowly arise, why did it suddenly STOP evolving. Why don’t we have various FL/UGs with different human groups enjoying bespoke FL/UGs specially tailored to optimally fit the peccadillos of their respective languages or dialects? Why don’t we have ethnically demarcated FL/UGs, some of which are ultra sensitive to rich morphology and some more sensitive to linear properties of strings? In other words, if FL/UG is complex why is it basically the sameacross the species, even in groups that have been relatively isolated from other human groups over longish periods of time. Note, the problem of stability is the flip side of the problem of recency. If large swaths of time make for easier gradual selection stories, they also exacerbate the problem of stability. Stasis in the face of environmental diversity (and linguistic environments sure have the appearanceof boundless diversity, as my typologically inclined colleagues never tire of reminding me) is a problem when gradual NS is taken to shape genetic material to optimally fit environmental demands. 

Curiously, the fact of stability over large periods of Evo time has become a focus of interest in the Evo world (think of Hox genes). The term of art for this sort of stability is “strong conservation” and the phenomenon of interest has been the strong conservation of certain basic genetic mechanisms over extremely long periods of Evo time. I just read about another one of these strongly conserved mechanisms in Quanta (here). The relevant conserved mechanism is one that explains biological patterns like those that regulate “[t]he development of mammalian hair, the feathers of birds and even those ridges on the roof of your mouth” (2). It is a mechanism that Turing first mooted before anyone knew much about genes or development or much else of our contemporary bio wisdom (boy was this guy smart!). There are two interesting features of these Turing Mechanisms (TMs). First, they are very strongly conserved (as we shall see) and second, they are very simple. In what follows I would like to moot a claim that is implicit in the Quanta discussion: that simplicity enables strong conservation. You can see why I like this idea. It provides a biological motivation for “simple” mechanisms that seems relevant to the language case. Let me discuss the article a bit.

It makes several observations. 

First, the relevant TM, what is called a “reaction-diffusion” mechanism is “beautifully simple.” Here is the description (2):

It requires only two interacting agents, an activator and an inhibitor, that diffuse through tissue like ink dropped in water. The activator initiates some process, like the formation of a spot, and promotes the production of itself. The inhibitor halts both actions. 

Despite this simplicity, the process can regulate widely disparate kinds of patterns: “spaced dots, stripes, and other patterns” including the pattern of feathers on birds, hair, and, of relevance in the article, denticles (the skin patterning) on sharks (2). 

Second, this mechanism is very strongly conserved. As the same TM regulates bird feathers and denticles then we are talking about a mechanism conserved over hundreds of millions of years (4). As the article puts it quoting the author of the study (2):

According to Gareth Fraser, the researcher who led the study, the work suggests that the developing embryos of diverse backboned species set down patterns of features in their outer layers of tissue in the same way — a patterning mechanism “that likely evolved with the first vertebrates and has changed very little since.”

Third, the simplicity of the basic pattern forming mechanism does not preclude variation of patterns. Quite the contrary in fact. The simplicity of the mechanism lends itself to accommodating variation. Here is a longish quote (6):

To test whether a Turing-like mechanism could create the wide range of denticle patterns seen in other sharks and their kin, the researchers tweaked the production, degradation and diffusion rates of the activator and inhibitor in their model. They found that relatively simple changes could produce patterns that matched much of the diversity seen in this lineage. The skates, for example, tend to have more sparsely patterned denticles; by either increasing the diffusion rate or decreasing the degradation rate of the inhibitor, the researchers could make more sparse patterns emerge.

Once the initial pattern is set, other, non-Turing mechanisms complete the transformation of these rows into fully formed denticles, feathers or other epithelial appendages. “You have these deeply conserved master regulator mechanisms that act early on in the development of these appendages,” Boisvert explained, “but downstream, species-specific mechanisms kick in to refine that structure.” Still, Boisvert stressed how remarkable it is that the mechanism underlying so many different biological patterns was theorized “by a mathematician with no biological training, at a time when little about molecular biology was understood.”

So, the simple mechanisms can be tweaked to generate pattern diversity and can be easily combined with other downstream non-TM “species-specific” mechanisms to “refine the structure” the basic TM lays down.

Fourth, the similarity of mechanism exists despite a wide variety of functions supported. Feathers are not hairs, and hairs and feathers are not denticles. They served different functions, yet formally they are generated by the same mechanism. In other words, the similarity is formal not functional and it is at this abstract formal (think “syntactic”) level that the common biological basis of these traits is revealed.

Fifth, the discovery of TMs like this one (and Hox, I assume) “bolsters a growing theme in developmental biology that “nature tends to invent something once, and plays variations on that theme”” (quote is from Alexander Schier of Harvard bio). 

Sixth, the article moots the main point relevant to this wandering disquisition; that the reason TMs are conserved is because they are so very simple (6):

Turing mechanisms are theoretically not the only ways to build patterns, but nature seems to favor them. According to Fraser, the reliance on this mechanism by so many far-flung groups of organisms suggests that some kind of constraint may be at work. “There simply may not be many ways in which you can pattern something,” he said. Once a system emerges, especially one as simple and powerful as a Turing mechanism (my emphasis, NH), nature runs with it and doesn’t look back.

What makes the mechanism simple? Well, one that is relevant for linguists of the MP stripe is that you really cannot take part of the reaction-diffusion function and get it to work at all. You need both parts to generate a pattern and you need nothing but these two parts to generate the wide range of patterns attested.[2]In other words, half a generation diffusion pattern does you no good and once you have one you need nothing more (see first quoted passage above). I hope that this sounds familiar (don’t worry, I will return to this in a moment).

I think that each point made is very linguistically suggestive, and we could do worse than absorb these suggestions as regulative ideals for theoretical work in linguistics moving forward. Let me elaborate.

First, simplicity of mechanism can account for stability of that mechanism in that simple mechanisms are easily conservable. Why? Because they are the minimum required to generate the relevant patterns (the reaction-diffusion pattern is as simple a system as one needs to generated a wide variety of patterns). Being minimal means that so long as such patterns eventuate in functionally useful structure at leastthis much will be needed. And given that simple generative procedures combine nicely with other more specific “rules” they will be able to accommodate both variation and species-specific bespoke adjustments. Simple rules then are both stable (because simple) and play well with others (because they can be added onto) and that is what makes them very biologically useful.[3]  

IMO, this carries over to operations like Merge perfectly. Merge based dependencies come in a wide variety of flavors. Indeed, IMO, phrase structure, movement, binding, control, c-selection, constituency, structure dependence, case, theta assignment all supervene on merge based structures (again, IMO!). This is a wide variety of different linguistic functions all built on the same basic Merge generated pattern. Moreover, it is compatible with a large amount of language specific variation, variation that will be typically coded into lexical specifications. In effect, Merge creates an envelope of possibilities that lexical features will choose among. The analogy to the above Turing Mechanisms and the specificity of hair vs skin vs feathers should be obvious.

Second, Merge, like TMs, is a very simple recursive function. What does it do? All it does is combine two expressions and nothing more! It doesn’t change the expressions in combining them I any way. It doesn’t do anything butcombine them (e.g. adds no linear information). So if you want a combination operation then Merge will be as simple an operation as you could ask for. This very simplicity and the fact that it can generate a wide range of functionally useful dependencies is what makes it stable, on a par with TMs.

Third, we should steal a page from the biologists and assume that “nature tends to invent something once.” In the linguistic context this means we should be very wary of generative redundancy in FL/UG, of having different generative operations serving the same kinds of structural ends. So, we should be very suspicious of theories that multiply ways of establishing non-local dependencies (e.g. bothI-merge andAgree under Probing) or two ways of forming relative clauses (e.g. both matching (Agree) and raising (i.e. I-merge)).[4]In other words, if Merge is required to generate phrase structure and it also suffices to generate non-local dependencies then we should not immediately assume that we have otherways of generating these non-local dependencies. It seems that nature is Okhamist, and so venerating Okham is both methodologically andmetaphysically (i.e. biologically, linguistically) condign.

Fourth, it is hard to read this article and not recognize that the theoretical temperament behind Turing’s conjectures about mechanism is very similar to those that motivate Chomsky. Here is a nice version that theoretical sentiment (6):

“Biological diversity, across the board, is based on a fairly restricted set of principles that seem to work and are reused over and over again in evolution,” said Fraser. Nature, in all its exuberant inventiveness, may be more conservative than we thought.

And all that linguistic diversity we regularly survey might also be the output of a very restricted set of very simple Generative Procedures. That is the MP hope (and as I have noted, IMO it has been reasonably well vindicated (as I have argued in various papers recently released or forthcoming)), and it is nice to see that it is finding a home in mainstream biology.[5]

Enough. The problem of stability of FL/UG smells a lot like the problem of deep conservation in biology. It also sseems like simplicity might have something to say about why this might be the case. If so, the second motivation for MP simplicity might just have some non-trivial biological motivation.[6]

[1]It is likely worse than this. As Jerry Fodor often noted, we are doubly removed from the basic mechanisms in that genes grow brains and brains secrete minds. The inference from behavior to genes thus must transit through tacit assumptions about how brains subvene minds. We know very little about this in general and especially little about how brains support linguistic cognition. Hence, all inferences from phenotypic simplicity to genetic simplicity are necessarily tenuous. Of course, if this is the best that one can do, one does it realizing the pitfalls. Hence this is not a critique, just an observation, and one, apparently, that extends to virtually every attempt to ground “behavior” in genes (as Lewontin long ago noted). 

[2]Here’s another thought to chew on: it is the generative procedure that is the same (a reaction-diffusion mechanism) not the outputs. So it is the functions in intentionthat are conserved notthe extensions thereof, which are very different.

[3]I cannot currently spell this out but I suspect that simplicity ties in with modularity. You get a simple mechanism and it easily combines with others to create complexity. If modularity is related to evolvability (which sure smells right) then simplicity will be the kind of property that evolving systems prize.

[4]This is one reason I am a fan of Sportiche’s recent efforts to reanalyze all relativization in terms of raising (aka, I-merge). More specifically, we should resist the temptation to assume that when we see different constructions evincing different patterns that the generative procedures underlying these patterns are fundamentally different.

[5]And we got there first. It is interesting to see that Chomsky’s reasoning is being recapitulated inside biology. Indeed, contrary to the often voiced complaint that linguistics is out of step with the leading ideas in biology, it seems to have been very much ahead of the curve. 

[6]Of course, it does not need this to be an important ideal. Methodological virtue also prizes simplicity. But this is different, and if tenable, important.

Inchoate minimalism

Chomsky often claims that the conceptual underpinnings of the Minimalist Program (MP) are little more than the injunction to do good science. On this view the eponymous 1995 book did not break new ground, or announce a new “program” or suggest foregrounding new questions. In fact, on this view, calling a paper A Minimalist Program for Linguistic Theory was not really a call to novelty but a gentle reminder that we have all been minimalists all along and that we should continue doing exactly what we had been doing so well to that point. This way of putting things is (somewhat) exaggerated. However, versions thereof are currently a standard trope, and though I don’t buy it, I recently found a great quote in Language and Mind (L&M) that sort of supports this vision.[1] Sorta, kinda but not quite.  Here’s the quote (L&M:182):

I would, naturally, assume that there is some more general basis in human mental structure for the fact (if it is a fact) that languages have transformational grammars; one of the primary scientific reasons for studying language is that this study may provide some insight into general properties of mind. Given those specific properties, we may then be able to show that transformational grammars are “natural.” This would constitute real progress, since it would now enable us to raise the problem of innate conditions on acquisition of knowledge and belief in a more general framework….

This quote is pedagogical in several ways. First, it does indicate that at least in Chomsky’s mind, GG from the get-go had what we could now identify as minimalist ambitions. The goal as stated in L&M is not only to describe the underlying capacities that make humans linguistically facile, but to also understand how these capacities reflect the “general properties of mind.” Furthermore, L&M moots the idea that understanding how language competence fits in with our mental architecture more generally might allow us to demonstrate that “transformational grammar is “natural”.” How so? Well in the obviously intended sense that a mind with the cognitive powers we have would have a faculty of language in which the particular Gs we have would embody a transformational component. As L&M rightly points out, being able to show this would “constitute real progress.” Yes it would.

It is worth noting that the contemporary conception of Merge as combining both structure building and movement in the “simplest” recursive rule is an attempt to make good on this somewhat foggy suggestion. If by ‘transformations’ we intend movement, then showing how a simple conception of recursion comes with a built in operation of displacement goes some distance in redeeming the idea that transformational Gs are “natural.”[2]

Note several other points: The L&M quote urges a specific research strategy: if you are interested in general principles of cognition then it is best to start the investigation from the bottom up. So even if one’s interest is in cognition in general (and this is clearly the L&M program) then right direction of investigation is not from, e.g. some a priori conception of learning to language but from a detailed investigation of language to the implications of these details for human mental structure more generally. This, of course, echoes Chomsky’s excellent critiques of Empiricism and its clearly incorrect and/or vacuous conceptions of reinforcement learning. 

However, the point is more general I believe. Even if one is not Empiricistically inclined (as no right thinking person should be) the idea that a body of local doctrine concerning a specific mental capacity is an excellent first step into probing possibly more general capacities seems like excellent method. After all, it worked well in the “real” sciences (e.g. Galileo’s, Copernicus’ and Kepler’s laws were useful stepping stones to Newton’s synthesis) so why not adopt a similar strategy in investigating the mind/brain? One of GGs lasting contributions to intellectual life was to demonstrate how little we reflexively know about the structure of our mental capacities. Being gifted linguistically does not imply that we know anything about how our mind/brain operates. As Chomsky likes to say, being puzzled about the obvious is where thinking really begins and perhaps GG’s greatest contribution has been to make clear how complex our linguistic capacities are and how little we understand about its operating principles.

So is the Minimalist Program just more of the same, with nothing really novel here? Again, I think that the quote above shows that it is not. L&M clearly envisioned a future where it would be useful to ask how linguistic competence fits into cognition more broadly. However, it also recognized that asking such “how” questions was extremely premature. There is a tide in the affairs of inquiry and some questions at some times are not worth asking. To use a Chomsky distinction, some questions raise problems and some point to mysteries. The latter are premature and one aim of research is to move questions from the second obscure mystical column to the first tractable one. This is what happened in syntax around 1995; the more or less rhetorical question Chomsky broached in L&M in the late 60s became a plausible topic for serious research in the mid 1990s! Thus, though there is a sense in which minimalism was old hat, there is a more important sense in which it was entirely new, not as regards general methodological concerns (one always values simplicity, conciseness, naturalness etc) but in being able to ask the question that L&M first posed fancifully in a non-trivial way: how does/might FL fit together with cognition more generally?

So what happened between 1968 and 1995? Well, we learned a lot about the properties of human Gs and had plausible candidate principles of UG (see here for some discussion). In other words, again to use Chomsky’s framing (following the chemist Davy), syntax developed a “body of doctrine” and with this it became possible to use this body of doctrine to probe the more general question. And that’s what the Minimalist Program is about. That’s what’s new. Given some understanding of what’s in FL we can ask how it relates to cognition (and computation) more generally. That’s why asking minimalist questions now is valuable while asking them in 1967 would have been idle.

As you all know, there is a way of framing the minimalist questions in a particularly provocative way, one that fires the imagination in useful ways: How could this kind of FL with these kinds of principles have evolved? On the standard assumption (though not uncontroversial, see here on the “phenotypic gambit”) that complexity and evolvability are adversarial, the injunction to simplify FL by reducing its linguistically proprietary features becomes the prime minimalist project. Of course, all this is potentially fecund to the degree that there is something to simplify (i.e. some substantive proposals concerning what the operative FL/UG principles are) and targets for simplification became worthwhile targets in the early 1990s.[3] Hence the timing of the emergence of MP.

Let me end by ridding off on an old hobbyhorse: Minimalism does not aim to be a successor to earlier GB accounts (and its cousins LFG, HPSG etc). Rather MP’s goal is  to be a theory of possible FL/UGs. It starts from the assumption that the principles of UG articulated from 1955-1990s are roughly correct, albeit not fundamental. They must be derived from more general mental principles/operations (to fulfill the L&M hope). MP is possible because there is reason to think that GB got things roughly right. I actually do think that this is correct. Others might not. But it is only once there is such a body of FL/UG doctrine that MP projects will not be hopelessly premature. As the L&M quote indicates, MP like ambitions have been with us for a long time, but only recently has it been rational to hope that they would not be idle.

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[1] Btw, L&M is a great read and those of you who have never dipped in (and I am looking at anyone under 40 here) should go out and read it.

[2] And if we go further and assume that all non-local dependencies are mediated by ((c)overt) movement then all variety of transformations are the product of the same basic “natural” process. Shameless plug: this is what this suggests we do.

[3] Why then? Because by then we had good reasons for thinking that something like GB conception of UG was empirically and theoretically well-grounded. See here (and four following entries) for discussion.

How to make an EVOLANG argument

Bob Berwick recently sent me something that aims to survey, albeit sketchily, the state of play in the evolution of language (evolang) and a nice little paper surveying the current state of Gould and Lewontin’s spandrels paper (here) (hint: their warning is still relevant). There have also been more than a few comments in FOL threads remarking on the important progress that has been made on evolang. I believe that I have invited at least one evolang enthusiast to blog about this (I offered as much space as desired, in fact) so as to enlighten the rest of us about the progress that has been made. I admit that I did this in part because I thought that the offer would not be taken up (a put up or shut-up gambit) and also (should the challenge be accepted) because I would really be interested in knowing what has been found given my profound skepticism that at this moment in time there is anything much to find.  In other words, for better or for worse, right now I doubt that there is much substantive detail to be had about how language actually evolved in the species.[1] In this regard, we are not unlike the Paris Academy over a century ago when it called for a moratorium on such speculation.

That said, who can resist speculating? I can’t. And therefore, this post was intended to be an attempt to examine the logic of an evolution of language account that would satisfy someone like me. I wanted to do this, because, though close to vacuous most of the discussion I’ve seen is (like the fancy inversion here?), I think that Minimalism has moved the discussion one small conceptual step forward. So my intention had been to outline what I think this small step is as well as point to the considerable distance left to travel.  

As you can tell from the modal tenses above, I was going to do this, but am not going to do it. Why not? Because someone has done this for me and instead of my laying out the argument I will simply review what I have received. The text for the following sermon is here, a recent paper by Chomsky on these matters.[2] It is short, readable and (surprise, surprise) lays out the relevant logic very well. Let’s go through the main bits.

Any discussion of evolang should start with a characterization of what features of language are being discussed. We all know that “language” is a very complex “thing.” Any linguist can tell you that there are many different kinds of language properties. Syntax is not phonology is not semantics. Thus in providing an evolutionary account of language it behooves a proposal to identify the properties under consideration.

Note that this is not an idiosyncratic request. Evolution is the study of how biological entities and capacities change over time. Thus, to study this logically requires a specification of the entity/capacity of interest. This is no less true for the faculty of language (FL) than it is for hearts, kidneys or dead reckoning. So, to even rationally begin a discussion in evolang requires specifying the properties of the linguistic capacity of interest.

So, how do we specify this in the domain of language? Well, here we are in luck. We actually have been studying these linguistic capacities for quite a while and we have a rich, developed, and articulate body of doctrine (BOD) that we can pull from in identifying a target of evolutionary interest. Chomsky identifies one feature that he is interested in. He terms this the “Basic Property” (BP) and describes it as follows:

[E]ach language yields a digitally infinite array of hierarchically structured expressions with systematic interpretations at interfaces with two other internal systems, the sensorymotor system for externalization and the conceptual system, for interpretation, planning, organization of action, and other elements of what are informally called “thought.” (1)

So one evolang project is to ask how the capacity that delivers languages with these properties (viz. I-languages) arose in the species. We call the theory of I-languages “Universal Grammar” or UG as it “determines the class of generative procedures that satisfy the Basic Property” (1). We can take UG as “the theory of the genetic component of the faculty of language.” If we do, there is a corresponding evolang question: how did UG arise in the species?[3]

Note, that the above distinguishes FL and UG. FL is the mental system/”organ” that undergirds the human linguistic competence (ie. The capacity to develop (viz. “grow”) and deploy (viz. “use”) I-languages). UG is the linguistically specific component of FL. FL is likely complex, incorporating many capacities only some of which are linguistically proprietary. Thus, UG is a subpart of FL. One critical evolang question then is how much of FL is UG. How much of FL consists of linguistically proprietary properties, capacities/primitives that are exclusively linguistic?

Why is the distinction important? Well, because it sure looks like humans are the only animals with BP (i.e. nothing does language like humans do language!) and it sure looks like this capacity is relatively independent of (viz. dissociates with) other cognitive capacities we have (see here). Thus, it sure looks like the capacity to generate BP-I-languages (BPIs) is a property of humans exclusively. And now we come to the interesting evolang problem: as a point of evolutionary logic (we might dub this the Logical Problem of Language Evolution (LPLE)) the bigger the UG part of FL, the more demanding the problem of explaining the emergence of FL in the species. Or as Chomsky puts it (3): “UG must meet the condition of evolvability, and the more complex its assumed character, the greater the burden on some future account of how it might have evolved.”

We can further sharpen the evolvability problem by noting one more set of boundary conditions on any acceptable account. There are two relevant facts of interest, the first “quite firm” and the second “plausible” and that we refer to with “less confidence.”  These are:

1.     There has been no evolution of FL in the species in the last 50k years or more.

2.     FL emerged in the way it exists today about 75k years ago.

As Chomsky puts it (3): “It is, for now, a reasonable surmise that language –more accurately UG- emerged at some point in the very narrow window of evolutionary time, perhaps in the general neighborhood of 75 thousand years ago, and has not evolved since.”[4]

Why is (1) firm? Because there are no known group differences in the capacity humans have in acquiring and using a natural language. As the common wisdom is that our ancestors left Africa and their paths diverged about 50kya then this would be unexpected were there evolution of FL or UG after this point.

Why is (2) less firm? Because we infer it to be true based on material cultural artifacts that are only indirect indicators of linguistic capacity. This evidence has been reviewed by Ian Tattersal (here) and it looks like the conclusion he draws on these issues is a plausible one. Chomsky is here relying on this archeological “consensus” view for his “plausible” second assumption.

If these assumptions are correct then, as Chomsky notes (3)  “UG must be quite simple at its core” and it must have emerged more or less at once. These are really flip sides of the same claim. The evolutionary window is very narrow and so whatever happened must have happened quickly in evo-time and for something to happen quickly it is very likely that what happened was a small simple change. Complexity takes a long time. Simplicity not so much.[5] So, what we are looking for in an evolang account of our kinds of natural langauges is some small change that has BPI-effects. Enter Minimalism.

Chomsky has a useful discussion of the role of evolvability in early Generative Grammar (GG). He notes that the evolvability of FL/UG was always recognized to be an important question and that people repeatedly speculated about it. He mentions Lenneberg and Luria in this regard, and I think I recall that there was also some scattered discussion of this in the Royaumont conference. I also know that Chomsky discussed these issues with Francois Jacob as well. However, despite the interest of the problem and the fact that it was on everyone’s radar the speculation never got very far. Why not? Because of the state of the theory of UG.  Until recently, there was little reason for thinking that UG was anything but a very complicated object with complex internal structure, many different kinds of primitives, processes and conditions (e.g. just take a look at GB theory). Given the LPLE, this made any fruitful speculation idle, or, in Dwight Whitney’s words quoted by Chomsky: “The greater part of what is said and written about it is mere windy talk” (4) (I love this Ecclesiastical description: Wind, wind, all is wind!).

As Chomsky notes, minimalism changed this. How? By suggesting that the apparent complexity of UG as seen from the GB angle (and all of GB’s close relatives) is eliminable. How so? By showing that the core features of BPIs as described by GB can be derived from very a simple rules (Merge) applied in very simple ways (computationally “efficient”). Let me say this more circumspectly: if to the degree that MP succeeds to that degree the apparent complexity of FL/UG can be reduced. In the best case, the apparent complexity of BPIs reduces to one novel language specific addition to the human genome and out falls our FL.  This one UG addition together with our earlier cognitive apparatus and whatever non-cognitive laws of nature are relevant suffice to allow the mergence of the FL we all know and love. If MP can cash this promissory note, then we have taken a significant step towards solving the evolang problem.

Chomsky, of course, rehearses his favorite MP account (7-9): the simplest Merge operation yielding unordered merges, the simplest application of the rule to two inputs yielding PS rules and Movement, natural computational principles (not specific to language but natural for computation as such) resulting in conditions like Inclusiveness and Extension and something like phases, the simple merge rule yielding a version of the copy theory of movement with obvious interpretive virtues etc.  This story is well known, and Chomsky rightly sees that if something like this is empirically tenable then it can shed light on how language might have evolved, or, at the very least, might move us from windy discussions to substantive ones.

Let me say this one more way: what minimalism brings to the table is a vision of how a simple addition might suffice to precipitate an FL like the one we think we have empirical evidence for. And, if correct, this is, IMO, a pretty big deal. If correct, it moves evolang discussion of these linguistic properties from BS to (almost) science, albeit, still of a speculative variety.

Chomsky notes that this does not exhaust the kinds of evolang questions of interest. It only addresses the questions about generative procedure. There are others. One important one regards the emergence of our basic lexical atoms (“words”). These have no real counterpart in other animal communication systems and their properties are still very hard to describe.[6] A second might address how the generative procedure hooked up to the articulatory system. It is not unreasonable to suppose that fitting FL snugly to this interface took some evolutionary tinkering. But though questions of great interest remain, Chomsky argues, very convincingly in my view, that with the rise of MP linguistics has something non-trivial to contribute to the discussion: a specification of an evolvable FL.

There is a lot more in this little paper. For example, Chomsky suggests that much of the windiness of much evolang speculation relates to the misconceived notion that the natural language serves largely communicative ends (rather than being an expression of thought). This places natural languages on a continuum with (other) animal communication systems, despite the well-known huge apparent differences. 

In addition, Chomsky suggests what he intends with the locution ‘optimal design’ and ‘computationally efficient.’ Let me quote (13):

Of course, the term “designed” is a metaphor. What it means is that the simplest evolutionary process consistent with the Basic Property yields a system of thought and understanding [that is sic (NH)] computationally efficient since there is no external pressure preventing this optimal outcome.

“Optimal design” and “computational efficiency” are here used to mean more or less the same thing. FL is optimal because there is no required tinkering (natural selection?) to get it into place.  FL/UG is thus evolutionarily optimal. Whether this makes it computationally optimal in any other sense is left open.[7]

Let me end with one more observation. The project outlined above rests on an important premise: that simple phenotypic descriptions will correspond to simple genotypic ones. Here’s what I mean. Good MP stories provide descriptions of mental mechanisms, not  neural or genetic mechanisms. Evolution, however, selects traits by reconfiguring genes or other biological hardware. And, presumably, genes grow brains, which in turn secrete minds. It is an open question whether a simple mental description (what MP aims to provide) corresponds to a simple brain description, which, in turn, corresponds to a simple “genetic” description. Jerry Fodor describes this train of assumptions well here.[8]

…what matters with regard to the question whether the mind is an adaptation is not how complex our behaviour is, but how much change you would have to make in an ape’s brain to produce the cognitive structure of a human mind. And about this, exactly nothing is known. That’s because nothing is known about how the structure of our minds depends on the structure of our brains. Nobody even knows which brain structures it is that our cognitive capacities depend on.

Unlike our minds, our brains are, by any gross measure, very like those of apes. So it looks as though relatively small alterations of brain structure must have produced very large behavioural discontinuities in the transition from the ancestral apes to us…

…In fact, we don’t know what the scientifically reasonable view of the phylogeny of behaviour is; nor will we until we begin to understand how behaviour is subserved by the brain. And never mind tough-mindedness; what matters is what’s true.

In other words, the whole evolang discussion rests on a rather tendentious assumption, one for which we have virtually no evidence; namely that a “small” phenotypic change (e.g. reduction of all basic grammatical operations to Merge) corresponds to a small brain change (e.g. some brain fold heretofore absent all of a sudden makes an appearance), which in turn corresponds to a small genetic change (e.g. some gene gets turned on during development for a little longer than previously).  Whether any of this is correct is anyone’s guess. After all there is nothing incoherent in thinking that a simple genetic change can have a big effect on brain organization, which in turn corresponds to a very complex phenotypic difference. The argument above assumes that this is not so, but the operative word is “assume.” We really don’t know.

There is another good discussion of these complex issues in Lenneberg’s chapter 6, which is worth looking at and keeping in mind. This is not unusual in the evolution literature, which typically assumes that traits (not genes) are the targets of selection. But the fact that this is commonly the way that the issues are addressed does not mean that the connections assumed from phenotypic mental accounts to brains to genes are straightforward. As Fodor notes, correctly I believe, they are not.

Ok, that’s it. There is a lot more in the paper that I leave for your discovery. Read it. It’s terrific and provides a good model for evolang discussions. And please remember the most important lesson: you cannot describe the evolution of something until you specify that thing (and even then the argument is very abstract). So far as I know, only linguists have anything approaching decent specifications of what our linguistic capacities consists in. So any story in evolang not starting from these kinds of specifications of FL (sadly, the standard case from what I can tell) are very likely the windy products of waving hands. 

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[1] Happily, I have put myself in the good position of finding out that I am wrong about this. Marc Hauser is coming to UMD soon to give a lecture on the topic that I am really looking forward to. If there are any interesting results, Marc will know what they are. Cannot wait.

[2] I’d like to thank Noam for allowing me to put this paper up for public consumption.

[3] Please observe that this does not imply that BP is the only property we might wish to investigate, though I agree with Chomsky that this is a pretty salient one. But say one were interested in how the phonological system arose, or the semantic system. The first step has to be to characterize the properties of the system one is interested. Only once this is done can evolutionary speculation fruitfully proceed. See here for further discussion, with an emphasis on phonology.

[4] It is worth noting that this is very fast in evolutionary terms and that if the time scale is roughly right then this seems to preclude a gradualist evolutionary story in terms of the slow accretion of selected features. Some seem to identify evolution with natural selection. As Chomsky notes (p. 11), Darwin himself did not assume this.

[5] Furthermore, we want whatever was added to be simple because it has not changed for the last 50k years. Let me say this another way: if what emerged 100kya was the product of slow moving evolutionary change with the system accreting complexity over time then why did this slow change stop so completely 50kya? Why didn’t change continue after the trek out of Africa? Why tones of change before hand and nothing since? If the change is simple, with not moving parts, as it were, then there is nothing in the core system to further evolve.

[6] I’ll write another post on these soon. I hope.

[7] If this reading of Chomsky’s intention here is correct, then I have interpreted him incorrectly in the past. Oh well, won’t be the last time. In fact, under this view, the linguistic system once evolved need not be particularly efficient computationally or otherwise.  On this view, computationally efficient seems to me “arose as a matter of natural law without the required intervention of natural selection.”

[8] The relevant passage is