Evolution of a Metaphor
Cat in the Stack
Is it possible that a poor understanding of how metaphor works is messing up our scientific view of evolution? Could it really be so much about language? The English teacher sighs.
This is a new insight, and I may recant it later, so I'm going to try not to name names, except where I am certain I'm on solid ground. I've been reading Olivia Judson's stunning series on Darwinism with great interest and I'm impressed by, first, her returning to Darwin himself and doing some close textual analysis that allows her to talk about which views of evolution are still powerful and which ones have, well, evolved so much that no one really remembers that Darwin himself didn't hold them. She makes distinctions between Darwin, Darwinism, and evolution--distinctions, which she underscores, are blurring in all directions. If you don't follow her blog in the NY Times, I recommend it highly. She is always interesting, smart, and fresh. I don't always agree but it doesn't matter. She's never, to my mind, tricky and when I disagree it is because the ground is firm enough for a disagreement. Here's some Judson that I like a lot: "I'd like to abolish the insidious terms Darwinism, Darwinist, and Darwinian. They suggest a false narrowness to the field of modern evolutionary biology, as though it was the brainchid of a single person 150 years ago, rather than a vast, complex and evolving subject to which many other great figures have contributed." (http://judson.blogs.nytimes.com/2008/07/22/a-natural-selection/: that's the url for the NY Times piece if you subscribe; and I usually add her columns to my del.icio.us page, if you follow me there.)
Now comes the part where I'm not comfortable, yet, naming names. Yesterday, I was reading a book on neural evolution by one of the scientists I admire most. His explanations of synaptic function, his take on the famous Hebbian theory ("neurons that fire together, wire together") seems exactly right to me . . . but then he makes that crazy leap that I've discussed before in these blogs and starts accounting in functional social and rationalist terms for various complex visual processing and memory processing mechanisms mediated by the frontal and parietal cortex, extends those operations to various other physiological components of attention, and arrives, quite quickly, at a "how come?" explanation of the process by reference to evolutionary forces operating upon the evolution of vertebrates. Hmmm. My much-admired scientist lost me somewhere in the Early Pleistocene with that leap.
I found myself rereading and rereading the section where we were supposed to follow him as he bounded from one cliff to the other over a one and a half million year crevice. And I hit on this word: "selection." The scientist was using the word as if it had one meaning and that the meaning was, as we English teachers say, denotative not connotative. Take saccadic eye movements. Saccades select, their rapidity is about focus and attention (saccades are the fastest of all our body's reflexive responses to external stimulus). If I'm studying something, my eyes are moving extremely rapidly, each movement sending new and slightly different information to my brain, not just Brodmann's Area 8, so much written about, but various different parts that also connect with movement, balance, flight-or-fight responses, and every other part of me that needs the information and detail required to respond.
"Selection," in this instance, in talking about saccades, has the verbal connotations of the result of the process of selecting in the verbal, active sense of to specify, focus, attend, and direct but with less of the evaluative content of approximate other words (synonyms) which have greater emphasis on choice, preference, discrimination, judgment. (Regular readers of this blog know that I came very close to going into Artificial Intelligence as a field, even into graduate school was pulled into that direction. I was particularly interested in the nexus of philosophy and math, back in the day, where language was rendered as equations to understand its fine discriminations. Believe me, once upon a time I would have happily done this paragraph with numbers and symbols and letters, and I still have to pull myself back from the edge when I think on this level . . . my mind could ease into that world of minutely differentiating linguistic analyses and never come out again!) But I digress.
If you look up "selection" and "select" in any dictionary, you find that English pays a lot of attention to that particular word. Why? It is part of our cultural-linguistic inheritance that we attend to the cluster of words around selection, choice, distinction, and discrimination--all the kinds of words that are about the rational, wilful or will-full (to emphasize the pun), and volitional creation of values and categories. Rational selection is something we insist upon as significant and meaningful. Other languages don't care nearly as much about the nuances of "rational" or "selection." Japanese, for example. Lots of fine discriminations are made in Japanese but this emphasis on supposedly rational and willful choice in the individual's selection-process is considered by the Japanese to be "very Western" and, well, a tad naive. But that's another topic for another day. Suffice to say, that we are extremely select, in the English language, about selection as an activity and our common usages of "select" and "selection," if you parse them with care, reveal the minute gradations in judgment, credibility, and certainty that we make as fast and detailed and focused as, well, saccades (and just as reflexive and unconscious too).
So back to my brain scientist who wants to explain "it all" by natural selection. He is skipping, not just in one book but in several (I ran from the paragraph that stumped me to my bookshelf to confirm this), from the meaning of "selection" and "to select" that pertains to saccades to the very loose and metaphoric use of "selection" in Darwin. Darwin, of course, also uses the word differently in many places, and there's been ample debate about exactly what he means. But here's a bottom line. The "selection" in "natural selection" is very different than the "selection" I've defined above in reference to saccades. "Natural selection" is not using that same will-full nuance and connotation of "selection" or, if it did, it wouldn't be, well, natural. That is, if the evolutionary process were about a form of discriminating, rational, wilful evaluation and selection, that would undermine exactly the process of inheritance that natural selection is supposed to be about. The words don't mean the same thing in these two cases. Natural selection is a metaphor and my scientist's skip from the way saccadic movements select different, multiple, instanteous views of an object in order to gain more information from it is itself a metaphoric one ("select" isn't entirely right for what saccades do) and is again metaphoric as it moves to "natural selection." Again, if I were still practiced in analytic philosophy I could do some chicken scratching that would convince you that the areas of overlap between the two uses of "select" and "selection" in these instances are not meaningful, certainly not meaningful enough to sustain that leap across the 1.5 million year crevice.
When people in my home field of literature produce semantic sleights of hand, using the subtle composites embedded in words to make a case that seems the same but is profoundly not, they are often either making for beautiful friction, as in an Emily Dickinson or Wallace Stevens poem, or they are using language casually and aren't aware of the distinctions or--as sometimes happens skillfully or deceptively--they are counting on the sleight of hand to fudge a contradiction so profoundly unsettled that ordinary language doesn't comprehend its slipperiness. Stanley Fish has made this into an art form; Walter Benn Michaels does it too, usually more in the manner of polemical bludgeon than artistry. Skillful trial lawyers all do this too. It's canny but ultimately a decpetive and sometimes even manipulative abuse of the ambiguities of powerful connotative words. It can fool a lot of the people a lot of the time because language is a shorthand; it rarely just denotes but rather suggests a line of inference that we then follow through. It's easier than a magician producing an elephant instead of the pretty girl to confuse an argument by using the same word to connote very different ideas. Unless you are a logician or schizophrenic (one major form of schizophrenia focuses on the minute changes in the use of words from one sentence to another: most of us generalize and just "get the drift" and don't focus on those shifts), you can be fooled by the way the finite number of words actually glosses over infinite variations in the meanings of words. It doesn't matter much of the time but, in intellectual argument, semantics are the basis on which arguments are built and it is not easy to wrangle all the nuances of every word.
Numerous scientists are also interested in metaphor, of course (Lakoff and Modell come to mind, but Lakoff, of course, is a linguist so he is trained in the ambiguities of language and makes great use of them in his popular writing and scientific papers). But I'm talking about something in addition to "metaphoric language" or "imagination." I'm referring to the way words can contain their opposite meaning, precisely because, in reducing complexity to language, there are vestigial traces of that which was excluded and sometimes those traces come back to haunt us in everyday speech as well as in the scientific literature.
"Deconstruction" was actually created as a method, brilliantly from my erstwhile point of view as a budding logician, to help catch those semantic and semiotic twists mid-sequence, to unravel the undercurrents of language fighting against the surface of similar words. So many scientists and social scientists hated the deconstructionist turn my field took back in the 1980s and 1990s. For them, literary theorists were all just making too complicated and jargony what wasn't complicated at all. WRONG!!! They got it so very wrong. There is nothing more complicated, more susceptible to foundational error and intellectual misunderstandings, than language.
In fact, deconstruction's deepest point was that so many of the bad generalizations and even so many of the good ones that are part of so-called rational discourse--by humanists as well as by natural scientists and by social scientists--are precisely caught, and unknowingly so, in the nuances, contradictions, and contested unspoken meanings hidden by words that seem on the surface to be the "same words." Had the methodology been easier, everyone could have learned something from deconstruction, like how to be more careful about the kinds of questions you ask on surveys, where the same word in one question miscues a sequence of answers because of a different usage in another (I see this a lot in the studies I'm reading). So much crappy thinking could have been mended with more application of the mechanics of deconstruction. (In a perfect world, every scientific or social science study would require a Certified Deconstructionist on the team screening the language of our assessment tools . . . *__* )
Have I lost everyone now? I'll make a punchline here. Having spent a day pulling book after book after book off my shelf, and looking at the proforma and obligatory evolutionary argument that almost inevitably comes in the final chapter of an otherwise careful description and discussion of brain functionality, I am convinced that the word "selection" has a lot to answer for. I'm not finding any Fishian or Michaelsian cynicism in the sleight of linguistic hand in the slurping from one meaning of "selection" to another, or even in the sloshing (you will notice I'm using as many squishy connotative words as I can come up with) across and between all the nuances of meaning that our choice-words have in English. These brlliant, brilliant scientists, who have taught me so much about neural networks, are not, well, they are not Jacques Derrida. They are not Deconstructionists. In fact, if you showed them a page of deconstructive criticism most would say something discriminating and selective like "hogwash!" Yet it is precisely the deconstructionist's obsessive attention to the shifting and ever permeable and connotative qualities of language--especially the discriminations permeating the language of "selection"--that reveals how the argument itself is based on a fallacy, on the deceptions (and contradictions) inherent in the word "selection" itself.
Because of the politics of anti-evolutionists, I will end by saying explicitly that I am by no means anti-evolutionist. Not at all. The fossil record and species diversity prove evolution beyond any doubt that I can manufacture. Evolution is a historical fact, as one of my biologist friends likes to say. It is not a theory. However, the promiscuous and obligatory application of evolutionary biology and evolutionary psychology as an explanatory model for complex and often culturally-specific forms of human behavior is just bad science and bad thinking and sloppy application of slippery language. Bad thinking gives evolution a bad name. I am especially dubious when an evolutionary explanation for "human behavior" is summoned up to explain the inevitable evolutionary progress leading, as the night the day, to social arrangements that look an awfully lot like that of middle-class Americans living in the twenty-first century. That is absurd, wrong, false, and sometimes even ludicrous pseudo-science. It is the opposite of the scientific method to apply an evolutionary explanation in so many of the cases where it is applied now. It is a disciplinary genuflection (a disciplinary fudge) not a rational argument. And a lot of "evolutionism" is based precisely on the English-language ambiguities and discriminations around "selection"--as word, concept, practice, and, for want of a better word, ideology (i.e. selection is a key part of our culture's ideas of will, rationality, self, individualism, etc.). In short, we have to be far more select in our application of the metaphor of "selection."
Oh gosh. Next post, I promise, will be lighter. Here's one more punchline: "Selection" is a fraught and freighted word in English. Now, don't even get me started on "natural."
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Wow, great post. I've been thinking a lot about the role of metaphor in the (mis)understanding and (mis)application of evolutionary theory for the last few months -- especially after reading Lily Kay's brilliant Who Wrote the Book of Life?: A History of the Genetic Code, which helps to unpack much of the metaphoric-qua-factual language surrounding genetic discourses. "Selection," while certainly important, seems far from the only term that gets misused/misunderstood in this way. I'll be interested to read as you continue to pick some of these apart.
As an aside, I've also been thinking about the cultural factors (who gets what out of it?) that cause a lot of scientists to use the metaphors of evolution in other fields -- especially fields that have something to gain from a crossover with biological theory. AI is one that you mentioned. I saw a talk this past weekend on The Singularity and Emerging Robotics, and I found myself getting pretty frustrated at the overt and manipulative misapplication of evolutionary terminology in describing "evolving" robots who were "naturally selecting."
Expanding on the relationship of the selection metaphor and its connection to ideology:
Margret Evans, a psychologist at the University of Michigan, studies some of the ways that children, potential users of evolution, acquire evolutionist and creationist beliefs. Evans describes how Western religious and philosophical traditions emphasize essentialism, teleology, and intention, and in the process limit the cognitive appeal of natural explanations for the origins of species. She argues that because these ideas tend to show up repeatedly in public representations, they constrain the inferential reasoning capacities of the developing mind.
It’s an observation that suggests science’s own predilection for categorization is at the root of evolutionary biology’s social friction.
Evans, E. M. (2001). Cognitive and contextual factors in the emergence of diverse belief systems: Creation versus evolution. Cognitive Psychology, 42, 217-266.
Nice article. Thank you.
gabriel
I don't know that article but I'll obtain it right now. It sounds exactly what I happen to be looking for since I'm currently revising my chapter on infant knowledge acquistion and then moving on to "The Redneck Down the Hall," about how pre-schoolers, barely lingual, already adopt some of the deep structural values of their culture, long before Piaget gives them credit for being at a developmental stage where they can understand such complexit. The Van Ausdale/Feagin ethnographies of what children do when their parents aren't policing them suggest that kids enact those deep values very early and then work on them as they get older and older, Vygotsky-style, building on and filling in, but already having those values at base. So you read the deep structure of my blog posting because, yes, that's where I'm heading next in my book, to how we actually transfer cultural values cross-generationally. It isn't with words but with all the affect of everyday life, including words. Your comment is greatly appreciated.
Best, Cathy
evolutionary biology group
Group leader: Tadeusz J. Kaweckiresearch | master thesis opportunity | group members | publications | movie | ecology & evolution home
In the summer 2007 the group is moving to the University of Lausanne
June 2007: congratulations t oGeraldine Schwaller, Evelin Hürlimann and Ana Rita Gonçalves for completing their B.Sc. semester projects.
May 1, 2007: Congratulations to Munjong Kolss, PhD!
See this interesting comment on our work :)
Research: evolutionary biology of learningBackground...
Learning allows an animal to develop, within its lifetime, an adaptive response to a completely novel environment. The ability to learn is thus one of the top achievements of evolution. Although almost all animals have a nervous system and are capable of some forms of learning, the complexity of the nervous system and learning behaviors vary enormously. How this diversity has evolved, and why "intelligent" behavior developed in some taxa and not others, are one of the most exciting open questions in the evolution of animal kingdom. Yet, our understanding of factors and processes governing the evolution of learning is rudimentary. While fitness benefits of learning are relatively well understood, we know little about costs of learning, constraints on its evolution, and the nature of heritable variation on which natural selection can act. As with any fitness-related trait, knowledge of these aspects is essential for understanding why, how, and when improved learning ability evolves. We hope our research will contribute to filling this gap in our knowledge. The questions we address include:
We address these questions using the fruit fly Drosophila melanogaster as a study organism. Fruit flies are capable of a variety of forms of learning. Their short generation time and small size allows us to study in "real time" evolutionary changes occurring in experimental populations in response to controlled selection regimes ("experimental evolution"). Furthermore, the genetic tools available for this species and knowledge of its neurobiology allow us to take an interdisciplinary approach, combining behavioral, neurobiological, genetic and genomic approaches within an evolutionary framework. We collaborate with the Drosophila neurobiology group.
...and some results
We have shown that genetically-based improvement in learning ability can readily evolve under an ecologically relevant selection regime. Under the selection regime flies that learned to associate a potential oviposition medium with an aversive chemical (quinine), remembered this association, and continued to avoid this medium after the chemical has been removed, contributed more genes to the next generation. Within 20 generations these flies became able to learn substantially faster and remember much longer than their ancestors (Mery and Kawecki 2002, PNAS 99:14274-14279). This response generalizes to other stimuli and other olfactory aversive learning tasks, suggesting that evolution has acted on a "general" learning ability. However, the "smart" flies paid for their improved learning ability with reduced survival when food is scarce, presumably due to pleiotropic side-effects of genes that improve learning (Mery and Kawecki 2003, Proc. R. Soc. B 270:2465-2469, see also a comment by New Scientist). This indicates an evolutionary trade-off between learning ability and other aspects of performance. We have also shown that learning has operational costs: flies repeatedly forced to learn within their lifetime show a decline in fecundity (Mery and Kawecki 2004, Anim. Behav. 68:589-598). Finally, we have shown that long-term memory formation makes flies more vulnerable to environmental stress (Mery and Kawecki 2005, Science 308 p.1148).
In another set of experiments we tested the old idea that the ability to learn may facilitate genetically-based evolutionary change (known as the Baldwin effect). We could show that populations selected to prefer to oviposit on a pineapple substrate evolved a stronger genetically-based preference for pinapple if they were also given an opportunity to learn which medium should be preferred. However, the opposite effect of observed in populations selected for oviposition on another substrate (orange). These results indicate that the fact that a species learns can substantially affect its evolutionary change in a novel environment (Mery and Kawecki 2004, Evolution 58:757-767.). In collaboration with Honda Research Institute we are working on mathematical and computer models of this effect.
Perspectives
We are beginning to address the genetic and physiological bases of the improved learning and memory and their costs. This includes mapping of genes responsible for this evolutionary change, and using microarray technology to study changes in gene expression. Simultaneously, new projects are addressing the role of the environment in modulating learning ability and memory.
Extraordinary learning ability and its generalization – intelligence – are hallmarks of the human species. Was evolution of "higher" intelligence inevitable or accidental? Why has it occurred only in the human lineage? Have we paid for it? Are some diseases manifestations of costs of intelligence? And, finally, why has evolution produced cognitive abilities that are apparently useless from the viewpoint of natural selection, like our ability to solve differential equations? Given that both the laws of evolution and the basic molecular mechanisms of learning are universal, evolutionary research on model organisms should help to answer such questions about our own origins and nature.
The movieThe movie The Origin of Daphnia has been produced for Thomas Flatt's PhD defense. You don't know what it has to do with fly brains? Well, watch the movie...
Group membersCurrent
Former
- Frederic
Mery (PhD student 1999-2003, postdoc 2003-2006, now group leader at CNRS Gif sur Yvette)
- Stéphanie Rion (MSc student, 2006-07; now teacher at High School in Sion)
- Sévérine Buchel (BSc honors student, 2006)
- Rebekka Trüssel (BSc honors student, 2006)
- Anne-Laure Torche (MSc student 2005-06)
- Adrian Baumeyer (BSc honors student 2005, now Master student at U. of Basel)
- Ludivine Strambini (BSc honors student 2005)
- Silvia Rauch (MSc student 2003-04, now a PhD student at U. of Zurich)
- Thomas
K. Flatt (PhD student 2000-2004, now a postdoc at Brown University)
- Mathias Spichtig (Diploma student
2002-2003, now PhD student at University of Amsterdam)
- Marcel Salathe (Diploma student
2001-2002; PhD at ETH Zurich 2007)
- Nicole Vouilloz (Lab manager; now administrative manager, Centre for Integrative Genomics, University of Lausanne)
- Jonas Bieri (Diploma student 2000-2001, now consultant manager at IT Systems Basel)
- Simon Koechlin (Diploma student 1999-2000, now journalist)
Collaborators (current and former)- Reini Stocker and the Drosophila neurobiology group
in Fribourg
- Marla Sokolowski (University of Toronto, Canada)
- Alex Kraaijeveld (Imperial College, Silwood Park)
- Bertram Gerber (University of Würzburg)
- Thomas Préat (CNRS, Gif-sur-Yvette)
- Jean-Marc Devaud (University of Toulouse)
- Marie-Laure Parmentier (INSERM, Montpellier)
- Marc Tatar (Brown University, Providence, Rhode Island)
- Peter A. Abrams (University of Maryland,
College Park)
- Robert D. Holt (University of Florida,
Gainesville)
FundingFunding by the Swiss National Science Foundation and the Roche Research Foundation is gratefully acknowledged.