Review of "Intelligent Movement Machine"

Review of: Graziano, M.S.A. (2009). Intelligent Movement Machine: an ethological perspective on the primate motor system. Oxford University Press, Oxford, UK
by Bradly Alicea

Introduction

The field of human, animal, and robotic movement, portions of which have gone by many names in the literature, is a vast and moderately synthesized area of study. Part of the problem is that only a few people bridge the multiple areas of specialty that are essential for a truly comprehensive understanding of movement. Michael Graziano is one of these key people. Graziano works on the electrophysiology of primate motor cortex, but also has an interest in how this translates into animal behavior. This explains the subtitle of the book: an ethological perspective. Graziano's synthesis is actually two-fold: one is to organize the literature on movement in a systematic manner, and the other is to unite observations of animal behavior with what we know about the underlying neural mechanisms.

Structure of the book
Since the field of movement as defined in the last section is only moderately synthesized, Graziano devotes a large section of the book towards bringing evidence to bear from the literature. The focus is on electrophysiology in Primates, so those hoping to understand movement phenomena outside of simple limb movements and feeding behaviors might come away disappointed. However, he does spend some time discussing personal space and movement behavior, which draws from his work on defensive postures. Despite his somewhat diverse choice of topics, he certainly does not make a unified field theory-type proposition.

While he may spend a few too many chapters on reviewing the current state-of-the-art, it sets up the last few chapters of the book. In this portion of the book, Graziano explains how he spent some time at the Bronx zoo to better understand what he was observing in electrophysiological experiments. Anyone who was spent time at a zoo realizes that non-human Primates exhibit many complex and sophisticated physical behaviors, even in captivity. In this sense, Graziano's approach is a sorely needed addition to the literature.

Heart of the neuroethological approach
Ethology is different from approaches to human behavior in that the former focuses on fixed action patterns. These action patterns can range from preening to arm waving to head shaking. Typically, such behaviors are relatively easily quantifiable in that they are discrete and repetitive. In this way, fixed action patterns are also thought to have a relatively simple neural basis. Graziano uses this framework to explain how behaviors observed in nature are produced at the single-cell level. This is one way of resolving a frustration from earlier in his career that involved the constricted behavioral repertoire observed during traditional electrophysiological recordings.

One criticism of this approach, of course, is how complex movement observed in naturalistic settings map to electrophysiological results collected in highly-artificial environments. This returns us to Graziano's early-career angst and how these two approaches can be reconciled in the first place. On the one hand, he has certainly succeeded at thought-provocation. This work adds a critical missing piece to the story behind movement, and how it relates to both species differences and symbolic behavior. However, we must keep in mind that movement involving many different components is not simply additive, and that what might explain an isolated movement might not be the whole story when naturalistic movements are taken into account.

Conclusions

One statement that particularly resonated with me was a statement to the effect that some electrophysiologists think Graziano's approach is crazy. I think this statement sums up one of the biggest unsung problems in science today: although "interdisciplinary research" is a popular buzzword, most scientists have no idea how to appreciate the approaches of their colleagues in other fields. This has been an ongoing frustration in my own life, and I am not entirely convinced that such skills can be taught. Aside from sociological griping, the scientific basis of the book is most definitely sound. I find it a reasonable and innovative approach to a problem that has in some ways been studied to death, yet in other ways is still vaguely understood.

Dawkins talk, Michigan State University, 3/2/09

I attended the Richard Dawkins talk at MSU the other night. This was part of their WorldView lecture series. This was the first event in the series for which the Wharton Center was sold out (about 1200 or so seats). I have now attended lectures from four great minds in evolution: Richard Dawkins and E.O. Wilson (at Michigan State) and Ernst Mayr and Steven Jay Gould (at the University of Florida). Dawkins is good for
his combination of scientific and religious skepticism with evolutionary biology, which was in full form the other night.

The Dawkins talk was called "The Purpose of Purpose", and was a good general audience talk. I noticed how self-promoting the whole Dawkins enterprise was: his website looks like its part e-commerce website, part self-help guru website. This is a good model for aspiring intellectual brokers (e.g people who want to become rich and famous in exchange for 10 years of higher education). Anyways, the talk was about how not everything in the world around us has "purpose" (e.g. got there via a designer or is there for our utilization), and how things that look like they have purpose and things that DO have conscious purpose (such as art or human artifacts).

Our hosts for the evening. LEFT: Dr. Fred Dyer (MSU Zoology), RIGHT: Dr. Richard Dawkins (Oxford). COURTESY: Dr. Wesley Elsberry.

To accomplish this, he broke down purpose into two different types: archipurpose and neopurpose. Archipurpose involves things that are causal but not neccessarily purposeful (like a bird's wings or stars in the universe). When pre-scientific peoples looked up into the sky, they assumed that the stars were put there by God for our pleasure. They then built monuments and sacrified virgins accordingly. On the other hand, neopurpose is the direct byproduct of conscious intervention, and its products generally serve a definable purpose. This is not to be confused with the purpose of a bird's wing -- wings are there so that the bird can fly, but got there via natural selection rather than by a master
designer.

There were parts of the talk where he seemed a bit sluggish (perhaps it was just my imagination). The old Dawkins chestnut that our bodies are the vessels for our genes (and thus serve an archipurpose) was used as an example. while I understand what he is saying, I think that specific argument is a bit shortsighted. He also contrasted domesticated species, whose evolution is governed by neopurpose (artificial selection by human breeders) with wild, naturally-selected species. I thought this was an excellent way to drive this point home, and wished he had spent a bit more time exploring this theme. But overall, it was an outstanding talk.

Fred Dyer, the chair of our Zoology Department, fielded questions from the audience. At WorldView, questions are solicited from the audience and the moderator fields the best of the crop. This works well, since giving the mike to audience members in a first come, first serve fashion can lead to really bad questions. Dawkins revealed that he was not dogmatic about his atheism and skepticism: he would gladly change his mind in a heartbeat if he saw convincing scientific evidence of God. He also has no time for homeopathic medicine, which reminds me of a great quote from the Futurama episode "Crimes of the Hot":

Robot: Calling all scientists......

Human: I have a degree in homeopathic medicine!

Robot: You have a degree in boloney!

Dawkins is currently on a barnstorming tour across the USA. If you can catch one of his speaking engagements, I highly recommend it.

Digital Fish Library

Here is an invaluable resource for learning about fishes run by UCSD:

Digital Fish Library

It's mostly fish anatomy and physiology, but it's organized by phylogeny using an intuitive Flash interface. The information they provide is really good, especially when coupled with something like FishBase and/or the Tree of Life.

Darwin's Legacy

It's about that time....

February 2009 is officially Darwin's 200 birthmonth. The New York Times has most of this week's science section devoted to his legacy. I find it interesting that in the popular imagination, Darwin is viewed as being a one-trick pony. Most people don't realize this, but Darwin was what we might call a theoretical synthesist (like myself). That is, he took all of the accumulating evidence and put it forth in a coherent form. Sometimes people don't really like what you have to say, but it needs to be said.

NY Times Darwin spread

Put yourself in 19th century Europe. Consider that until the 16th century, most people knew very little if anything about the natural world outside of Europe. Consider further that the bible purportedly held all of the answers regarding how natural diversity and the earth itself got there. From the renaissance until the 19th century, Europeans observed things like fossils in cliff walls or novel species in Australia and had no frame of reference for which to put them in other than the Bible's great flood. Darwin's work essentially built on the work of people like Cuvier, Aggaziz, and other naturalists of the time. However, he added just that little bit of extra insight that made the difference between Darwin being a household name and Lamarck (who made an earlier attempt at synthesis) being widely ridiculed.

Below is a link to a list of Darwin's publications:

List of publications

Interestingly, he published not just the Origin of Species, but books on sexual selection and facial expressions, geology, and, towards the end of his life, plant behavior. In particular, he was interested in the effects of a hormone called Auxin on phototropism. Of course, Darwin was a man of his time in that he knew little about genes or biochemistry, and didn't test his many theories in an elegant manner. On the other hand, one could make the same accusations about Einstein. But such is the life of a synthesist.

Non-razors, unite!

A central assumption of modern science is parsimony, or that the simplest explanation also serves as the best explanation for a particular phenomenon. The principle behind this is the famous idea of "Occam's razor". Einstein is even famous for his expression "A theory should be as simple as possible but no simpler". This idea seems like a match made for explaining the evolutionary origins of lifeforms, especially those that are hyper-specialized. One might even say (especially maximum parsimony people) that a good razor makes for a good phylogeny.

Phylogeny constructed using maximum parsimony (this one exhibits long-branch attraction, which is a problem in such analyses). COURTESY: Wikipedia.

However, the underlying assumption of parsimony may not actually explain all instances of evolution. Consider that for as many examples of "good design" one can find in nature, there are many examples of less-than-optimal natural systems. To illustrate what I am getting at, I would point readers to the Rube Goldberg machine. Rube Goldberg was a cartoonist in the early 20th century who designed elaborate machines (many serially interacting parts) that produced a rather trivial output. For example, to turn off a light switch, we could design an elaborate mechanism that utilizes 30 different steps. Essentially, the number of parts is MAXIMIZED in the production of a particular output. I point you to these examples:

Example of a Rube Goldberg machine (COURTESY: Purdue University YouTube channel)

Considering the role of Rube Goldberg-like evolutionary mechanisms in a systematic way has (as far as I know) never really been done before. I have heard people mention casually that many transcriptional and metabolic pathways are of this quality, but have never seen a solid experimental or computational result. In a literature search, I did find reference to "anti-razor" advocates (who are mostly philosophers of science), but no serious inquiries into what we might call anti-razor biology.

The idea of maximizing the number of mechanisms, as the polar opposite of minimizing the number of mechanisms that people usually think of when pointing to examples of natural selection, is actually pretty intriguing to me. Let us suppose that an adaptive process in evolution operates as a game. The goal of this game is not to produce an optimal output, but to produce a unique solution that is complementary with the overall function of the organism. This could be the result of either cooperation or competition. A traditional biological arms race is similar to this: two organisms will compete in an iterative fashion to build bigger, more elaborate structures until they both end up with structures of ridiculous size. The original impetus of the arms race was to improve fitness. Ultimately, however, what becomes paramount (or enforces this runaway result) is the competition itself. It may be that two organisms (or set of genetic elements, or populations) compete against another such unit (or against nature) in a way that results in such a sub-optimal result. This would be natural selection working in a way counter to what most people would expect, but natural selection nonetheless.

Rube Goldberg meets Game Theory: is this a better mousetrap? COURTESY: Wikipedia.

Please send me examples of non-optimal mechanisms and traits in organisms (at any level of analysis -- from molecular pathways to social behavior). I am especially interested in the non-optimal products of evolution. Please post comments pointing to your own examples. In future posts, I may expand on this theme a bit more, so stay tuned.

POSTSCRIPT: I did elaborate on this a bit. Unfortunately, the empirical data is a bit sparse. Please see my arXiv paper "The 'Machinery' of Biocomplexity: understanding non-optimal architectures in biological systems" (arXiv:1104.3559, q-bio.QM) for further development of this idea.

For more information on how evolution (more specifically, natural selection) is or is not an optimizing force, please see: Orzack, S.H. and Sober, E.   Adaptationism and Optimality. Cambridge University Press, Cambridge, UK (2001).

Also, watch this "Richard Dawkins Presents" video showing an example of non-optimal evolution and unintelligent design (the laryngeal nerve in the giraffe, which is an artifact of fish physiology).