EVERY MATURE FIELD OF SCIENCE IS characterized by an established conceptual framework--what philosopher of science Thomas Kuhn called a "paradigm." Every now and then, according to Kuhn, scientists encounter a series of problems that cannot be resolved within the current paradigm. If this situation persists, a crisis eventually ensues, which is resolved by abandoning the reigning paradigm and embracing a new one.
The history of science, however, teaches us that things are not always that tidy. Biology, for instance, arguably has never undergone a paradigm shift since Darwin, although the Darwinian revolution does count as an entirely new paradigm when compared to William Paley's intelligent design-based explanations for the diversity of life. Rather, the original "Darwinism" of the mid-19th century with its twin concepts of common descent and natural selection was improved by the so-called neo-Darwinism of the late 19th century which eliminated any remaining vestiges of Lamarckism--the idea that environmentally-induced characters can be inherited. The first decades of the 20th century saw another marked expansion of evolutionary theory, which came to be known as the "Modern Synthesis'--a complex theoretical structure that reconciled the basic Darwinian ideas with the then new fields of Mendelian and statistical genetics.
The Modern Synthesis was arguably completed during the 1940s, with the publication of a series of seminal volumes by some of the preeminent evolutionary biologists of the time, including Theodosius Dobzhansky, Ernst Mayr, and George Gaylord Simpson. To this date, graduate level textbooks are built around the same conceptual structures laid out by the Modern Synthesis, although of course much has happened in biology since: the molecular revolution, the rebirth of the study of the evolution of development ("evo-devo") and the genomic era, to name a few. The question has therefore been posed by several people over the past decade or so: do we need an Extended Evolutionary Synthesis? Stephen Jay Gould among others thought so, and he tried to articulate one in his last technical book, The Structure of Evolutionary Theory.
To further explore the nature of a possible Extended Evolutionary Synthesis, Gerd Muller and I recently hosted a workshop on the current status of evolutionary theory at the Konrad Lorenz Institute for Evolution and Cognition Research, in Altenberg near Vienna, Austria. We invited 16 people who have been active in discussions of this kind and asked them to talk about where they think evolutionary biology is going. The so-called "Altenberg 16" are: John Beatty (University of British Columbia), Wemer Callebaut (University of Hasselt), Sergey Gavrilets (University of Tennessee), Eva Jablonka (Tel Aviv University), David Jablonski (University of Chicago), Marc Kirschner (Harvard University), Alan Love (University of Minnesota), Gerd Muller (University of Vienna), Stuart Newman (New York Medical College), John Odling-Smee (Oxford University), Massimo Pigliucci (Stony Brook University), Michael Purugganan (New York University), Eors Szathmary (Collegium Budapest), Gunter Wagner (Yale University), David Sloan Wilson (Binghamton University), and Greg Wray (Duke University).
In order to appreciate what we did in Altenberg, however, one first needs to understand the Modern Synthesis. At the beginning of the 20th century, standard Darwinian theory was in a bit of a crisis because it seemed incompatible with the rediscovery of Mendelian genetics, which in turn seemed hard to reconcile with statistical genetics (what today is called quantitative genetics). The new Mendelian genetics seemed to show that traits are controlled by discrete units (the genes) which would produce only discrete phenotypes. This was contrary to the requirement of continuous variation on which Darwin had built his gradualistic theory, as well as to the work being carried out by statistical geneticists (termed biometricians), who were interested in characters that display the typical bell curve, or continuous distribution. The resolution to this impasse emerged gradually, thanks to the work of Ronald Fisher, Sewall Wright, J.B.S. Haldane and the already mentioned additional architects of the Modern Synthesis. Essentially, population genetics theory as we know it today was born, and it elegantly showed the compatibility of Mendelian genetics, statistical genetics, and neo-Darwinism: some characters are influenced principally by few genes, and they follow Mendelian roles, but many others are influenced by tens or hundreds of genes, whose separate effects produce a cumulatively smooth, bell-shaped distribution. Both Mendelian and quantitative characters am then subject to natural selection, as Darwin maintained.
The Modern Synthesis itself, however, was clearly born incomplete, as all scientific theories are, to some extent. For instance, the extrapolation of population genetic processes to the long time periods that are the province of paleontology was assumed with little additional discussion. The entire body of knowledge in embryology and developmental biology was set aside because it had not been developed within an evolutionary framework. And even ecology was simply assumed to be part of the picture, as opposed to being organically integrated in a coherent conceptual framework. Moreover, in the almost 70 years since the Modern Synthesis, biologists have uncovered the structure of DNA, found that there are types of inheritance that are not directly tied to the genes (so called epigenetic effects), started a whole new field of evolutionary developmental biology, and discovered molecular mechanisms that are capable of unleashing a wide array of phenotypic changes under stressful conditions ("capacitors" of phenotypic evolution), affecting what has come to be known as the "evolvability" of populations and species. Paleontologists such as Gould and Niles Eldredge have shown that the fossil record has much to teach us about the tempo and mode of evolution, and theoretical models have indicated that the Modern Synthesis' relatively simple conception of population genetic phenomena barely scratches the surface of the reality of biological dynamics. More controversially, complexity theory has for the first time since the Darwin-Paley dispute offered us the possibility of additional mechanisms, besides natural selection, that can generate order and complexity.
None of the above should be misconstrued as a rejection of the Modern Synthesis, or of neo-Darwinism, or even of the original Darwinism insight. On the other hand, one can easily see why there has been much excitement and discussion in the field over the past decade or so: so many new empirical discoveries, and so much conceptual advancement in a variety of areas of theoretical biology are bound to raise the question of whether a theoretical structure put in place seven decades ago is still entirely adequate to the task. Hence the workshop at Altenberg and the forthcoming edited book that MIT Press is going to publish in 2009 with each author contributing a chapter covering a wide range of topics, including: "Chance, History, and Natural Selection," "The Epigenetic Turn: The Challenge of Soft Inheritance," "Phenotypic Plasticity as Causal Factor in Evolution," "Modularity, Evolvability, and the Evolution of Genetic Architecture," "The Structure of Evolutionary Theory and Biological Knowledge."
Predictably, not everybody agrees that there is any need of an Extended Evolutionary Synthesis. Some of my colleagues have been commenting, in print or at meetings, that all the new stuff is perfectly compatible with the current paradigm, or that there isn't really much radically new, especially conceptually, and therefore there is no reason to call for special meetings or discussions. I must respectfully disagree with the "conservatives" in this case. First, there is a difference between compatibility and implication: few people (including myself) argue that the new discoveries and theoretical advancements are incompatible with the Modern Synthesis. However, it seems to me much harder to argue that the new material was "implied" by the Modern Synthesis and that therefore there really isn't much radically new to talk about. Second, it is easy to show--as a matter of historical record--that ideas like evolvability, capacitance, epigenetics in the modern sense, phenotypic plasticity, or emergent complexity were simply nonexisting in the biological literature at the time of the Modern Synthesis. If these terms have distinct meanings as opposed to being simple reformulations of older ideas--and they do--then there is much novelty out there that biologists need to deal with.
Of course, the proof in science is always in the pudding: only time will tell whether we are moving toward a true and significant expansion of the basic conceptual framework of evolutionary biology, or we are simply tweaking some of the peripheral branches of the same structure that Darwin and the modern synthesists put in place. While we are waiting for the long-term outcome, we have to deal with the usual nonsense on the part of creationists, intelligent design proponents and the like. In this case, the opening shot was published by an independent journalist, Suzan Mazur, who wrote a piece in the New Zealand-based online outlet Scoop entitled "Altenberg! The Woodstock of Evolution?" in which she characterized the workshop as "a gathering of 16 biologists and philosophers of rock star stature." The hype, rather embarrassing to begin with, reached a crescendo as the article progressed, when Mazur stated that "despite the fact that organizers are downplaying the Altenberg meeting as a discussion about whether there should be a new theory, it already appears a done deal.... Indeed, history may one day view today's 'Altenberg 16' as 19th century England's 'X Club' of 9--Thomas Huxley, Herbert Spencer, John Tyndall, et al.--who so shaped the science of their day." Okay, few people would mind being compared to a rock star (though, alas, without the corresponding income), and any scientist would certainly enjoy being referred to as a modern day Thomas Huxley (the famous "Darwin's bulldog" of the Victorian age), but Mazur's presentation of the scope of the workshop was misleading at best.
Mazur's long article turned out to be a hopelessly confused hodgepodge of actual science, badly misunderstood science, philosophy good and bad, and crackpotism. For instance, one of the characters introduced by Mazur to the public was Stuart Pivar, an art collector who had been sending more or less threatening emails to me, my graduate students, and several of my colleagues because we were not taking seriously his "theory" about the evolution of development. (Pivar's "theory" is based on the idea that all life forms are variants of one basic form, a concept that arches back to pre-Darwinian times---and his "proof' is that he can build plastic models that can be reshaped as one wishes by twisting and turning them.) Mazur presented Pivar as a scientist who "is not dependent on government grants to carry out his work" (tree, except that he is not a scientist, and I seriously doubt he would be able to get government grants if he applied), and one who "has paid the price for [his unorthodox theory] on the blogosphere." In other words, Mazur painted us as rock star celebrity-rebels, and Pivar as a misunderstood genius who is shunned by the scientific community because of a secret natural selection cabal. Needless to say, both portraits are as far from the troth as an episode of the X-Files.
This may have been nothing more than an amusing incident and one more reminder of what can happen when one talks to journalists without double-checking their credentials. But we live in the era of the Internet, and the matter was far from being over. The very same day, Paul Nelson, a contributor to "Uncommon Descent"--the official blog of the pro-intelligent design Discovery Institute--picked up on the Scoop article, declaring it worthy of attention on the grounds that "evolutionary theory is in--and has been, for a long time--a period of great upheaval. Much of this upheaval is masked by the noise and smoke of the ID debate, and by the steady public rhetoric of major science organizations, concerned to tamp down ID-connected dissent." Oh boy. To my further surprise, not only was Nelson's short commentary picked up by a variety of pro- and anti-evolution blogs, but eventually the Mazur article came to the attention of serious media outlets, including the New York Times, Science and Nature. Science published a detailed article the same week the workshop was being held, beginning with a whole paragraph devoted to Mazur's "coverage." At least the Science reporter wryly pointed out that I am no Jimi Hendrix, shifting immediately to a more realistic portrayal of what we actually did in Austria that summer.
But Mazur herself wasn't through. She began publishing on Scoop a six-part "investigative" story entitled "The Altenberg 16: Will the Real Theory of Evolution Please Stand Up?" Once again, this turned out to be a longwinded ramble that displayed in full color Mazur's lack of understanding of the subject matter and penchant for conspiracy theorizing. What was both illuminating and amusing was the shifting portrayal of yours truly that she presented to her readers. In the first article I was introduced as that "rare combination--a consummate scientist with a sense of humor," and she made a charming reference to the fact that I had a birthday present in my hands for my daughter. But subsequently I made the mistake of making dear, politely I thought, that I was not too pleased with the distortions that Mazur was responsible for. This turned me into a rather shady character in her later articles. "Massimo Pigliucci is a man on the move," she wrote, "but who is he? And why was he born in Liberia during the regime of William Tubman?" (because my father was there working for a British company that built roads, she could have found out, had she asked). From consummate scientist I had become "flamboyant" (something she clearly didn't mean as a compliment) and observations on my sense of humor had given way to remarks on my receding hair line (a sad but tree fact of life in my '40s).
What one should not take home from this story is what many of my colleagues have too quickly concluded: that one should not talk to reporters. Scientists have an ethical duty to the public to explain what they do and why. This is because what scientists do may indeed affect the public welfare, and even when it doesn't, it is probably funded, directly or indirectly, by tax payers' money. Moreover, it simply does not help the image of science if scientists keep propagating the stereotype of the white coat aloof in the ivory tower. But by the same token, journalists also have a duty to do their homework and to present stories in an interesting, but not unduly sensationalist, fashion. We are all after the Nobel or the Pulitzer, at least in our dreams, but few of us have even a fighting chance to get there. In the meantime, we ought to do our job, science or journalism, with the degree of seriousness that is rightly expected from professionals, not to mention quite simply from the fact that we are grownups.
The web site of the Konrad Lorenz Institute devoted to the Altenberg meeting: http://kli.ac.at/workshops-c.html?stuff/ workshops/wtb-08a
The original Mazur article on "the Woodstock of Evolution": http://www.scoop.co.nz/stories/HL0803/S00051.htm
The beginning of Mazur's six-part "expose" of evolutionary theory: http://www.scoop.co.nz/stories/HL0807/S00053.htm
My own final entry on the Rationally Speaking blog about the Altenberg events: http://rationallyspeaking.blogspot.com/ 2008/07/altenberg-2008-what-happened.html
A Panda's Thumb blog entry on the creationist nonsense surrounding the Altenberg workshop: http://pandas thumb.org/archives/2007/07/luskin-has-lost.html
A Pharyngula blog entry commenting on the Altenberg meeting and some of the hype generated by creationists: http://scienceblogs.com/pharyngula/2008/07/altenberg_2008_is_over.pbp
Carroll, R. L. 2000. "Towards a New Evolutionary Synthesis." Trends in Ecology and Evolution 15: 27-32.
Dobzhansky, T. 1937. Genetics and the Origin of Specks. New York, Columbia University Press.
Fisher, R. A. 1930. The Genetical Theory of Natural Selection. Oxford, Clarendon.
Gould, S.J. 2002. The Structure of Evolutionary Theory. Cambridge, MA, Harvard University Press.
Haldane, J. B. S. 1932. "The Time of Action of Genes, and its Bearing on Some Evolutionary Problems." The American Naturalist 66: 5-24.
Kuhn, T. 1970. The Structure of Scientific Revolutions. Chicago, University of Chicago Press.
Love, A. C. 2006. "Evolutionary Morphology and Evo-Devo: Hierarchy and Novelty." Theory in Biosciences 124: 317-333.
Mayr, E. 1942. Systematics and the Origin of Species. New York, Dover.
Mayr, E. and W. B. Provine 1980. The Evolutionary Symbols. Perspectives on the Unification of Biology. Cambridge, MA, Harvard University Press.
Muller, G. B. 2007. "Evo-Devo: Extending the Evolutionary Synthesis." Nature Reviews Genetics Advanced Online Publication, November: 1-7.
Newman, S. A. 2005. "The pre-Mendelian, Pre-Darwinian World: Shifting Relations Between Genetic and Epigenetic Mechanisms in Early Multi-cellular Evolution." Journal of Bioscience 30: 75-85.
Pennisi, E. 2008. "Modernizing the Modern Synthesis." Science 321: 196-197.
Pigliucci, M. 2007. "Do We Need an Extended Evolutionary Synthesis?" Evolution 6112: 2743-2749.
Pigliucci, M. and J. Kaplan 2006. Making Sense of Evolution: The Conceptual Foundations of Evolutionary Biology. Chicago, IL, Chicago University Press.
Robert, J. S. 2004. Embryology, Epigenesis, and Evolution: Taking Development Seriously. Cambridge, England, Cambridge University Press.
Simpson, G. G. 1944. Tempo and Mode in Evolution. New York, NY, Columbia University Press.
Sultan, S. E. 2007. "Development in Context: The Timely Emergence of Evo-Devo." Trends in Ecology and Evolution 2211: 575-582.
Wagner, G. P. 2007. "The Developmental Genetics of Homology." Nature Genetics 8: 473-479.
Wright, S. 1932. "The Roles of Mutation, Inbreeding, Crossbreeding and Selection in Evolution." Proceedings of the Sixth International Congress of Genetics: 356-366.…