Friday, March 20, 2015

Some weekend reads

1. This blog entry discusses the review processes in sociology and how it is being affected by Nate Silver’s online 538 sight. Lindner (the author of the scooped paper) makes a provocative point concerning the value added of the review process. Here’s a taste of the argument:

Silver writes for a new technocratic audience and produces posts with “outputs from multivariate regression analyses, resplendent with unstandardized coefficients, standard errors, and R2s.” It might not have quite the rigor of academic papers, but it yields many of the same results. Even more importantly, “Unlike academics, Silver is unburdened by the constraining forces of peer review, turgid and esoteric disciplinary jargon, and the unwieldy format of academic manuscripts. He need not kowtow to past literature, offer exacting descriptions of his methods, or explain in tedious detail how his findings contribute to existing theory.”

2. Johan Bolhuis sent me this fascinating pair of papers (here, here) on cortical computations in mammals and birds. It seems that birds and mammals share a common cortical circuitry strongly suggesting that what we have and what they have brains wise is pretty much the same thing. As the Harris paper puts it:

Perhaps intelligence isnt such a hard trick after all: a basic circuit capable in principle of supporting advanced cognition might
have evolved hundreds of millions of years ago, but only adapted to this purpose when the benefits actually outweighed the costs
of increased head size, development time, and energy use. Tool-use wouldnt do much for a sheep; those few times intelligence was favored by evolution, it may have appeared with remarkably little effort, by repurposing an ancient circuit most animals use for other things.

Johan sent me this short additional very suggestive comment. Very soon the question may not be why we have merge but why every thing else doesn’t? Or maybe they do, but we can’t see it yet?

There you have it! More evidence to suggest that you don’t need big neural changes to achieve ‘cognitive’ changes. As I like to put it in talks: the basic neurogenetic machinery is there in all vertebrates, it’s what you do with it that counts. In the case of humans and songbirds (and a few other taxa) - but not apes or mice - auditory-vocal imitation learning evolved with it, and in the case of humans (but not other species) ‘Merge’ evolved with it, possibly as the result of a mutation that led to a rewiring of the cortex.

3. Rainer Mausfield sent me a reference to a study that relates to the three-remark rule that I mentioned here. To repeat: it’s been my experience that if someone hears something three times at a conference and nobody objects, it becomes accepted wisdom.  It seems that there is some (weakish) data to back this up. Rainer sent me this link and this paper. Though the experiments are useful, the logic behind this seems sound to me. Say you are at a specialist conference and someone gives a talk that is not in your area of expertise, yet it seems not that persuasive. A reasonable strategy is to defer to the experts, who, you hope, can be counted upon to make the status of the (perhaps more controversial bits) clear in the question period. If this does not happen, then it is reasonable (on Bayes grounds, I believe) to conclude that the absence of criticism is a sign of the accepted truth of the claims.  So, if you hear something that you think objectionable it is incumbent upon you to speak up. Others will be taking their cure from you. This is part of what makes scientific inquiry a collective enterprise.

4. Caveat lector; this piece is from Aeon (the Vyvyan Evans venue)!! The author is Andreas Wagner (here) and he has a cross appointment at the Sante Fe Institute. At any rate, I found the discussion provocative and relevant for the EVOLANG discussion concerning the emergence of merge in the species. Here’s a useful quote:

How do random DNA changes lead to innovation? Darwin’s concept of natural selection, although crucial to understand evolution, doesn’t help much. The thing is, selection can only spread innovations that already exist. The botanist Hugo de Vries said it best in 1905: ‘Natural selection can explain the survival of the fittest, but it cannot explain the arrival of the fittest.’ (Half a century earlier, Darwin had already admitted that calling variations random is just another way of admitting that we don’t know their origins.)

This is obviously relevant to the question of how linguistic facility arose; where did it come from? If Chomsky is right in thinking that there is nothing quite like merge in our ancestors, then we need something other than a natural selection (NS) account for how it arose. Of course, once it arises, we can ask why it did not disappear (this is where NS would come in). But how it arrived? NS has nothing to say about this (though 2 above suggests that more may lay dormant than might meet the untutored eye).

Wagner believe that the “arrival” space is highly organized, thereby constraining possible evolutionary trajectories independently of the effects of NS (sound familiar? Think UG and “learning”). Wagner discusses how the space of genetic possibilities might be organized so as to be searchable by NS. He mentions that absent such a structure, the size of the possibility space would make evolution miraculous:

If you had to find a text on a specific subject in such a library – without a catalogue – you would get utterly lost. Worse than that, if missteps can be fatal, you would quickly die. Yet life not only survived, it found countless new meaningful texts in these libraries. Understanding how it did that requires us to build the catalogue that evolution lacks. It demands that we work out how these libraries are organised to comprehend how innovation through blind search is possible.

I have no idea whether this is right (though it sounds plausible to me). So if anyone has a grasp on these matters, please enlighten the rest of us. What seems clear is that if something like this is correct, it fits well with other work that constrains evolutionary trajectories coming from the Evo-Devo literature. There is more than a slight analogy between this kind of discussion and the one we had in cognition/linguistics 60 years ago.  When considering the mechanics of change two factors will always loom large: the set of possible trajectories and the set of factors that choose between these options. NS is a factor of the second type. Until recently (or so it seems to an outsider like me) the main idea has been that the range of possible trajectories was so humongous that the bulk of an evolutionary explanation would be carried by NS like factors. This no longer seems as clear. It looks like in evolution (as in “learning”) the range of options available are tightly constrained and so a (large?) part of any evolutionary account will advert to these circumscribed possibilities. It goes without saying (but I will say it) that any complete story will likely have factors of both kinds. However, it seems clear that the narrower the options, the less role there will be for NS/learning, the wider the options the greater the causal efficacy of NS/learning.  It’s interesting that biologists have started focusing on the restricted possibility space, as a major factor in evolutionary change.


  1. Just briefly on the Wagner piece - I'm reading his book (The arrival of the fittest) and very much enjoying it (only halfway through though - too many other things intervening). He was on BBC radio 4's Start the Week a month or so ago, and it was also good listening.

  2. "If you had to find a text on a specific subject in such a library – without a catalogue – you would get utterly lost. Worse than that, if missteps can be fatal, you would quickly die. Yet life not only survived, it found countless new meaningful texts in these libraries."

    Maybe a good time to un-dust one of those 1970ish Dawkins' books where he talks about the law of large numbers. "Life" does not care if 90% of a species dies [or gets lost in 'a library' - what an odd analogy; WHAT is life searching for besides passing on offspring to the next generation?]. But thanks for sharing the quotes; they nicely highlight why Chomsky and some following his lead on evolutionary miracles are so utterly confused.

    And, BTW, "biologists have NOT started focusing on the restricted possibility space, as a major factor in evolutionary change." - they already knew that possibilities were quite restricted back in the 1980s when I took my first evolution class...