Sunday, January 6, 2013

In Which Our Hero Trashes a Book He Has No Intention of Reading

One of the things that graduate school does to you is to destroy your reading habits. I spent my time there reading journal articles about upland game birds and the effects of human encroachment on the ecology of the dry grasslands of the southwestern United States. When I say "spent my time," I mean I read pretty much every minute when I wasn't in the field doing actual research, or teaching labs, or drinking with my labmates. I didn't read for pleasure, but it didn't stop me from acquiring books and saving them for the future. I have, therefore, a huge backlog of books that are up to twenty years old, waiting in my home office for me to work my way through them, and Mrs. Archaeopteryx has made me agree to read at least one book from the cache for each new book that I buy.

Of course, this doesn't keep her from buying new books, and occasionally I select one of her leftovers to be my "new" book. Recently, Mrs. Arch purchased Antifragile by Nassim Nicholas Taleb, the author of The Black Swan. She hated it--Taleb is a pompous asshole, and his attitude makes it difficult to take his ideas seriously. She didn't think I'd want to bother with the book, and I didn't really disagree. I don't find philosophy or economics interesting, and from what I could tell, the book seemed to be some sort of combination of both. Taleb argues that some entities (including some cultural and natural systems) are made stronger by exposure to stress, and that we're doing ourselves a disservice by trying to remove all stressors from our environments. Mrs. Arch told me that Taleb uses evolution as an example, and that's something I am interested in, so I decided to give the book a look.

I started with the "Prologue," and that was pretty much enough. Mrs. Arch was exactly right--Taleb is a blowhard anti-intellectual who started setting up "Soviet-Harvard" strawmen in the first couple of pages. This kind of irritation, I don't need. I thought, however, I'd at least read his thoughts on evolution, and not too surprisingly, he gets it wrong. Taleb shows a basic misunderstanding of the way that evolution operates; he makes the common mistake of thinking of evolution as some sort of progressive process that works to produce stronger species (although he does at least understand that natural selection works on populations, not individuals).  Taleb believes that exposure to stress--in this case, any change in the environment--works to remove organisms that are less "fit" from the gene pool (he also understands the difference between genes and organisms, but in this case it makes very little difference).  However, he conflates genetic fitness and resilience.  The way that evolutionary biologists use the term "fitness" has nothing necessarily to do with how strong or smart or fast an animal is, and simply indicates the ability of an organism to get its genes into the next generation.  Natural selection works by a winnowing-down process; those genes not well-adapted to a particular environment are reduced in number in subsequent generations, and eventually removed from the gene pool.  This does not, as Taleb argues, make a species more resilient, but less so.  The resilience of a species is based on its genetic variation; any reduction in that variation makes the species more susceptible to extinction if there is a change in the environment.

Evolution--specifically, selection--may be thought of as a "honing" process.  It fits a population to its environment, and results in some of the spectacular physical adaptations that we see in nature--the intricate beauty of a spider web, or the lovely curve of the wing of an albatross.  But those adaptations come with a price, and that price is the loss of genetic variation that would allow those organisms to deal with major disruptions of their environments.  Conversely, a lack of stress allows the retention of genetic variation that might be less favorable under current environmental conditions, but that might come in handy if the environment suddenly changes in a completely "unexpected" way.  For example, Peter Grant and his crew demonstrated that the beak size of Darwin's finches in the Galapagos tended to fluctuate with rainfall; when times are tough, beak sizes that are best adapted to deal with the hardiest seeds are selected, and intermediate sizes begin to disappear.  When times are good, and there are many types of seeds, intermediately sized bills remain in the population.  It's not too difficult to come up with a scenario in which the intermediate bills become the most beneficial, but if a long period of low rainfall has removed all those genes from the population, there are no birds with the "fittest" bill size.  In other words, stress has made the population less resilient than it would have otherwise been.

I didn't read any more of Taleb's book.  If he doesn't understand evolution, why should I trust his ideas about culture or the economy?  I have plenty of books from 2002 in the back room, and I have every reason to think that there's at least a chance that the authors knew what they were talking about.