About Rationally Speaking

Rationally Speaking is a blog maintained by Prof. Massimo Pigliucci, a philosopher at the City University of New York. The blog reflects the Enlightenment figure Marquis de Condorcet's idea of what a public intellectual (yes, we know, that's such a bad word) ought to be: someone who devotes himself to "the tracking down of prejudices in the hiding places where priests, the schools, the government, and all long-established institutions had gathered and protected them." You're welcome. Please notice that the contents of this blog can be reprinted under the standard Creative Commons license.

Tuesday, November 14, 2006

Making Sense of Evolution (the book)

This is going to sound a bit self-serving, but readers of this blog have in fact asked me to briefly comment on my own work from time to time (especially published columns in Skeptical Inquirer and Philosophy Now). I believe my new book, “Making Sense of Evolution: Toward a Coherent Picture of Evolutionary Theory” (Chicago Press), qualifies.

The first thing to know about the book is that, although it is in fact a critique of the limitations of the so-called Modern Synthesis, i.e. the current incarnation of evolutionary theory that has held sway since the 1940s, it should not in any reasonable way be construed as ammunition for creationism, intelligent design, and other such nonsense (of course, if someone wishes to unreasonably so construe the book, be my guest).

What the book (written in collaboration with my philosopher colleague, Jonathan Kaplan) attempts to do is a critical examination of the logic, consistency and applicability of some of the fundamental concepts used by evolutionary biologists. Some of these concepts include basic ones such as natural selection and biological species, as well as more esoteric ones like “adaptive landscapes” and “genetic constraints.” Jonathan and I claim that some of these ideas are problematic in the sense that they either can be construed in a variety of not necessarily clearly compatible ways, or they have a troubled relationship with what evolutionary biologists actually do in the course of their empirical research.

Take natural selection as an example. It can be thought of as a physical process resulting from the direct interaction between organisms and the environments in which they live. This is certainly the way Darwin thought about it. But in most modern biological literature it is actually defined (and empirically measured) as a statistical covariance between traits and measures of fitness, i.e. as an abstract property of populations. Jonathan and I go into great detail to show that biologists may be unaware of all the not-so-trivial complications that arise when one wishes to connect Darwin-style, individual-level natural selection with the way contemporary biologists use the “same” concept at the level of entire populations.

A second example, a bit more technical, concerns the idea of “adaptive landscapes.” This is a standard conceptual tool in evolutionary theory, and refers, well, Jonathan and I point out that it seems to refer to several things, not themselves easily connected to each other. The idea was introduced by Sewall Wright in the 1930s to present to a non-mathematical audience of biologists his way of thinking about the relationship between the genetic make-up of individuals and populations on the one hand and the corresponding fitnesses of the same genotypes on the other. To make the story short (for the longer version you'll have to read the book), Jonathan and I claim that the idea was fraught with problems and inconsistencies from the beginning, and that it has now been radically modified by the work of a mathematical biologist named Sergey Gavrilets. Sergey actually showed that the mathematical (and biological) properties of realistic (i.e., highly multidimensional) “landscapes” are very different from those of the 2- and 3-dimensional versions usually presented in textbooks and examined in most of the literature. Indeed, these differences are such that some old questions to which biologists have dedicated a large amount of effort ought to be rethought in an entirely different fashion, and may in fact cease to be relevant to our understanding of how evolution works. For example, the classic adaptive landscape problem is how does a population “move” from one adaptive peak to a higher one, i.e. how can evolution re-shape the genetic makeup of populations to increase their average fitness. The problem is that the “peaks” of the classic rendition are separated by maladaptive “valleys,” i.e. by combinations of genes that have lower fitness than the combinations currently present in the population. By definition, natural selection cannot bring a population “down” such a valley to reach a nearby peak, because it (selection) doesn't have forethought, it cannot sacrifice the immediate advantage for the long-term gain. Several ingenious (but largely unworkable) solutions have been proposed over a course of decades, until Gavrilets demonstrated that if the landscape is highly-dimensional (as must be the case for real organisms with tens of thousands of genes) the problem largely disappears because there are no “peaks” and “valleys,” but rather large continuous multidimensional hyper-planes of high fitness punctuated by occasional “holes” of low fitness (hence the term “holey landscapes” to refer to Gavrilets' theory). All natural selection has to do is keep the populations from falling into the holes, i.e. to evolve genetic constitutions that would drive the population to extinction. As I said, if you need more than this, read the book...

The main reason I liked working on this book, though, is because it represents a fairly rare (though certainly not unheard of) example of collaboration between a philosopher and a scientist, and I assure you it was much fun to get past (or around) the inevitable cultural barriers that separate the two cultures of the humanities and the sciences. Especially when the cross-cultural exchange is helped by some excellent wine from Jonathan's exceedingly well-stocked cellar.


  1. Bill,

    no, Making Sense of Evolution wouldn't be good for that purpose, it's a rather technical book.

    You may want to try my "Denying Evolution" (Sinauer), it's about creationism but it includes several chapters on the basics of both evolutionary theory and science in general.

    There are others, of course, e.g. R. Dawkins' "Climbing Mount Improbable" and E. Mayr's "This is Biology."

    People, feel free to chime in here.

  2. How about What Evolution Is by Mayr?

    Or books by Matt Ridley, such as The Agile Gene or Genome.

  3. IMO, Bill, Dawkins's "Climbing Mt. Improbable" is the best for understanding evolution itself, and if you want specifically arguments against creationism or other pseudo-scientific claptrap (nto that I'm biased or anything...), there's this book called "Denying Evolution" by some bloke called Max Pigliucci. You might have heard of him...

  4. As I said, if you need more than this, read the book...

    All biologists an of course the Evolutionary Theory need a lot of this!!!

  5. MP: "What the book" ... "attempts to do is a critical examination of the logic, consistency and applicability of some of the fundamental concepts used by evolutionary biologists. Some of these concepts include basic ones such as natural selection and biological species,"

    As I claim OFTEN, one would have to include pre-evolution and pre-big bang considerations to honestly and comprehensively include "logic".


  6. Cal, as I repeat to you _often_, pre-evolution and pre-big bang stuff simply has nothing to do with the scientific theory of evolution. Period.

  7. Pigliucci,

    I just came across PBS' WGBH's (Boston PBS station)Evolution project (2001). They have some good resources on teaching evolution and dealing with creationism. I have not seen the television series, but I have ordered it from the library. I was wondering what you thought of the project (http://www.pbs.org/wgbh/evolution/).

    What is the most detailed book or book series on the molecular evidence for common descent. What is the simplest known natural organism?

    Thanks. I like your Hovind debate a lot and wish there would someday be a debate just on the molecular evidence between a hard core expert (geek) and Hovind.

  8. MP: "Cal, as I repeat to you _often_, pre-evolution and pre-big bang stuff simply has nothing to do with the scientific theory of evolution. Period."

    Let me remind you, neither evolution or secularism has an origin or predominance inside of the reasons why we originally educated the masses in the first place. To me, it is much like the II law working inside of the constraints of knowledge and education. It's ran its course and now it's running down and becoming a degraded form of the original.

    The true reason we have public edu at all was on account of Martin Luther who wished to teach children to read the Bible.

    On the origins of the universe and physical principles therein, Scientific American suggests in "15 Answers to Creationist Nonsense" that there are no virtually no answers to the origins of the universe. However, aliens would be an acceptable consideration for all the things that we really don't understand and don't know the true origin of.

    "7. Evolution cannot explain how life first appeared on earth.

    The origin of life remains very much a mystery, but biochemists have learned about how primitive nucleic acids, amino acids and other building blocks of life could have formed and organized themselves into self-replicating, self-sustaining units, laying the foundation for cellular biochemistry. Astrochemical analyses hint that quantities of these compounds might have originated in space and fallen to earth in comets, a scenario that may solve the problem of how those constituents arose under the conditions that prevailed when our planet was young.

    Creationists sometimes try to invalidate all of evolution by pointing to science's current inability to explain the origin of life. But even if life on earth turned out to have a nonevolutionary origin (for instance, if aliens introduced the first cells billions of years ago), evolution since then would be robustly confirmed by countless microevolutionary and macroevolutionary studies." SA


    What was your favorite and customary use for the word credulous, again? Don't you think people really have the right to dig a little deeper and expect more of themselves and the formation of theories? I sure do.


  9. Timothy,

    I think the PBS evolution series was very good. As for molecular evolution, there are of course plenty of serious textbooks about it, but within the framework of the evolution-creation "debate" I'd check out Ken Miller's "Finding Darwin's God" (especially if you ignore the second part on quantum physics, which rapidly descends into nonsense...)

  10. Cal, in case you didn't know, evolution has nothing to say on the origin of life, which is the subject of abiogenesis. :rolleyes:

  11. Massimo Pigliucci: "You may want to try my 'Denying Evolution' (Sinauer), it's about creationism but it includes several chapters on the basics of both evolutionary theory and science in general.

    "There are others, of course, e.g. R. Dawkins' "Climbing Mount Improbable" and E. Mayr's "This is Biology.

    "People, feel free to chime in here."

    I've found "29+ Evidences for Macroevolution: The Scientific Case for Common Descent" to be a decent primer on evolution, especially for getting a feel for the breadth of support that evolution has.

  12. Wherever there is a gap in knowledge, there is someone with a god concept lurking.

  13. beepbeep
    Checked out your blog, and noted the entry for Nov. 13, which contains transcript of part of a lecture by Ken Miller, also a You-tube clip of same. Must be the lecture that Kevin Eric Clark was referring to.

    I'm sure that bill wouild find it as interesting interesting as I did.

    As I said, beepbeep has the transcript and the clip both, but
    here is the clip by itself.

    Notice what Miller says at the top about the Dover trial (ID response to genome evidence).

    In fact that's lots of juicy things in that trial.

  14. Kevin,

    I haven't read the Time magazine article. The problem is that I cringe whenever I hear attributes like "atheist" or "christian" to qualify the word scientist...

  15. I just blogged this on Evolving Thoughts. Note the hint in the text...

  16. John,

    I appreciate it, and will forward the link to Jonathan, including a pointer to the whink...

  17. bill:"The only thing about this is it purposely ignored the mechanisms of evolution in order to show evolutionary theory as independent of the exact mechanisms by which change occurs."

    That has been my exact problem for quite some time. I think that ignoring "how scientific principles were developed from point a to point b" is not an honest methodology at all.

    To me, evolution is a subset of a huge variety of more important issues. That is, either atomic theory or information theories are far more likely to reach the qualifications for a theory of "everything" than evolution could ever hope for. Started to think this after reading W. Heisenberg's "Uncertainty Principle" a long while ago.



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