evolutionary theory: the view from altenberg (m. pigliucci)
DESCRIPTION
Presentation used in a conference by Massimo Piglucci.TRANSCRIPT
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evolutionary theory:
the view from altenberg
by Massimo Pigliucci
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11 JULY 2008 VOL 321 SCIENCE www.sciencemag.org196
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Massimo Pigliucci is no Jimi Hendrix. Thissoft-spoken evolutionary biologist from StonyBrook University in New York state looksnothing like that radical hard-rock musicianwhose dramatic guitar solos helped revolution-ize rock nroll. But to Suzan Mazur, a veteranjournalist who occasionally covers science,Pigliucci is the headliner this week at a smallmeeting she believes will be the equivalent ofWoodstock for evolutionary biology. The invi-tation-only conference, being held inAltenberg, Austria, promises to be far moretransforming for the world than the 1969music festival, Mazur wrote online in Marchfor Scoop.co.nz, an independentnews publication in New Zealand.
That hyperbole has reverber-ated throughout the evolutionarybiology community, putting Pigliucci and the 15 other partici-pants at the forefront of a debateover whether ideas about evolu-tion need updating. The meremention of the Altenberg 16, asMazur dubbed the group, causessome evolutionary biologists toroll their eyes. Its a joke, saysJerry Coyne of the University ofChicago in Illinois. I dont thinktheres anything that needs fix-ing. Mazurs attention, Pigliucci admits,frankly caused me embarrassment.
Yet Pigliucci and others argue that the so-called modern synthesis, which has guided evo-lutionary thought and research for about 70 years, needs freshening up. A lot has hap-pened in the past half-century. DNAs structurewas revealed, genomes were sequenced, anddevelopmental biologists turned their sights onevolutionary questions. Researchers have cometo realize that heredity is not simply a matter of
passing genes from parent to offspring, as theenvironment, chemical modification of DNA,and other factors come into play as well. Organ-isms vary not only in how they adapt to chang-ing conditions but also in how they evolve.
Evolution is much more nuanced than thefounders of the modern synthesis fully appreci-ated, says Pigliucci. That doesnt mean that theoverall theory of evolution is wrong, as someintelligent design proponents have tried toassert using Mazurs story as support, but ratherthat the modern synthesis needs to better incor-porate modern science and the data revealed byit. More than genes pass on information from
one generation to the next, for example, anddevelopment seems to help shape evolutionscourse. Many things need fixing, emphasizesone invited speaker, Eva Jablonka of Tel AvivUniversity in Israel. I think that a new evolu-tionary synthesis is long overdue.
Modern tradition The modern synthesis essentially represents amarriage of the 19th century concept of evo-lution with Mendelian genetics, which was
rediscovered at the beginning of the 20th cen-tury; the birth of population genetics in the1920s added to the intellectual mix. By the1940s, biologists had worked out a set of ideasthat put natural selection and adaptation atevolutions core. Julian Huxleys 1942 book,Evolution: The modern synthesis, broughttogether this work for a broad audience.
Simply put, the modern synthesis holdsthat organisms have a repertoire of traits thatare passed down through the generations.Mutations in genes alter those traits bit by bit,and if conditions are such that those alter-ations make an individual more fit, then thealtered trait becomes more common overtime. This process is called natural selection.In some cases, the new feature can replace anold one; in other instances, natural selectionalso leads to speciation.
However, several concepts have arisensince then that make the modern synthesisseem too simplistic to some, Pigliucciamong them. In a 2007 Evolution paper, hecalled for the development of an extendedevolutionary synthesis. His plea coincidedwith a similar one made that year by GerdMller, a theoretical biologist at the Univer-sity of Vienna. Together, with support fromthe Konrad Lorenz Institute for Evolutionand Cognition Research in Altenberg, theyorganized this weeks conference, invitingmany who share the view that the modernsynthesis is incomplete. Whats happeningnow in evolutionary theory is as exciting andfoundational as during the early days, saysDavid Wilson of Binghamton University inNew York, another attendee.
Beyond genesInsights from ecology, developmental biology,and genomics in particular are nudging evolu-tionary biology away from a focus on popula-tion geneticshow the distribution of geneschanges across groups of individualsandtoward an understanding of the molecularunderpinnings of these changes. Better familytrees that give researchers greater confidenceabout the relatedness among organisms havehelped promote a credible, comparativeapproach to these mechanisms, says inviteeGnter Wagner, an evolutionary developmen-tal biologist at Yale University.
Some studies, for example, indicate thatdevelopment constrains evolution. From themodern synthesis perspective, Wagnerexplains, the body plan is a historical residueof evolutionary time, the afterglow of the evo-
Woodstock? Austrias Konrad Lorenz Institute forEvolution and Cognition Research is hosting a much-discussed evolutionary biology meeting.
Daring duo. Massimo Pigliucci (right) and Gerd Mller want toupdate the modern synthesis.
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h my gosh, says Massimo Pigliucci, maybe I shouldnt use that term. Pigliucci, responding to comments on his
talk about how living things respond to their environment, and what it means for evolution, has just let slip the p-word. Later the same day, Gnter Wagner, an evolutionary theorist at Yale University in New Haven, Connecticut, puts up a slide bearing the words Postmod-ern Synthesis. Pigliucci is moved to make an editorial suggestion from the floor: Id really rather we didnt use that term. Wagner says the slide was intended to be tongue-in-cheek, but Pigliucci is worried about the impression the word creates: If theres one thing we dont want, its for people to get the idea that theres a bunch of evolutionary theories out there, and that theyre all equal.
A lot of scientists loathe what they take to be postmodernisms intellectual relativism, and shy away from using the word. But doing so puts Pigliucci in something of a bind. An evolutionary ecologist at the State University of New York in Stony Brook, Pigliucci is one of the conveners of this small meeting on the future of evolutionary thought taking place at the Konrad Lorenz Institute for Evolution and Cognition Research in Altenberg, Aus-tria. The meeting has received a fair amount of hype in the blogosphere it was dubbed The Woodstock of Evolution. Its agenda is, pretty explicitly, to go beyond the modern synthesis that has held sway in evolutionary theory since
the middle of the twentieth century. And in everyday speech, it is pretty clear what comes after the modern.
Whats more, some of this work sounds as though it fits the term quite nicely. Over dinner at the meetings end, Pigliucci expresses his hope of moving from a gene-centric view of causality in evolution to a pluralist, multi-level causality. Postmodernists in the humani-ties call this decentering, and they are all for it. Over the course of the meeting, its fairly clear that the means to this pluralist end are being sought through mixing and matching neglected ideas and old problems from biologys past with the latest experimen-tal and analytical techniques. Apply that sort of bricolage to architecture and you get the sort of brutalist-right-angle here, classical-column-there, swirling-titanium-ceiling-above-it-all look that is normally pigeonholed, for better or worse, as postmodern.
Evolution of ideasLeaving aside the troublesome adjective, what is the modernism that the Altenburg meeting is meant to move beyond or to use Pigliuc-cis preferred term, extend1? Between about 1920 and 1940, researchers such as the Ameri-can Sewall Wright and the Englishmen Ron-ald Fisher and J. B. S. Haldane took Charles
Darwins ideas about natural selection and Gre-gor Mendels insights into how traits pass from parents to offspring which many biologists of the time believed antithetical and fused them into a mathematical description of the genetic makeup of populations and how it changes. That fusion was the modern synthesis. It treats an organisms form, or phenotype, as a readout of its hereditary information, or geno-type. Change is explained as one version of a
gene being replaced by another. Natural selection acts by chang-ing the frequency of genes in the next generation according to the fitness of phenotypes in this one. In this world view, the gene is a black box, its relation-ship to phenotype is a one-way street, and the environment, both cellular and external, is a selective filter imposed on the readout of the genes, rather
than something that can influence an organ-isms form directly.
Whats wrong with this picture, say the would-be extenders at Altenberg and else-where, is what it leaves out. Molecular biol-ogy, cell biology and genomics have provided a much richer picture of how genotypes make phenotypes. The extenders claim that enough insights have now come from this and other research for it to be time to re-examine prob-lems that the modern synthesis doesnt address. These problems include some of the key turning
Postmodern evolution?This summer a group of high-profile researchers met in
Altenberg, Austria, to try and plot the future course of evolutionary theory. John Whitfield was there.
The modern synthesis is good at modelling the survival of the fittest, but not the arrival of the fittest. Scott Gilbert
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NATURE|Vol 455|18 September 2008 NEWS FEATURE
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Evolutionary Theory 1.0: Darwinism
Common descent Natural selection
Missing a theory of heredity(after having flirted with Lamarckism
and blending inheritance)
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Evolutionary Theory 1.1: neo-Darwinism
Wallace Weissman
Rejection of Lamarckism Separation of soma and germ
Still missing a theory of heredity...
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Evolutionary Theory 2.0: the beginning of the Modern Synthesis
Fisher Haldane Wright
Compatibility between Mendelism and statistical genetics
Theories of selection and random drift: birth of population genetics
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Evolutionary Theory 2.1: the mature Modern Synthesis
Dobzhansky Mayr Simpson Stebbins
Variation in natural populations Species concepts, speciation processes Compatibility of gradualism with paleontology Applicability of Darwinism to variety of mating
and genetic systems in plants
Huxley
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The major tenets of the evolutionary synthesis were that populations contain genetic variation that arises by random mutation and
recombination; that populations evolve by changes in gene frequency brought about by random genetic drift, gene flow, and especially natural
selection; that most adaptive genetic variants have individually slight phenotypic effects so that phenotypic changes are gradual; that
diversification comes about by speciation, which normally entails the gradual evolution of reproductive isolation among populations; and that
these processes, continued for sufficiently long, give rise to changes of such great magnitude as to warrant the designation of higher taxonomic levels.
Doug Futuyma
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Do we need Evolutionary Theory 3.0? Toward an Extended Synthesis
[the Modern Synthesis] is strictly a theory of genes, yet the phenomenon that has to be explained in evolution is that of the transmutation of form.
(Karl Popper)
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How do we factor in development? Is evolution always gradual? Is selection the only organizing principle? What are the targets of selection? Is there a discontinuity between micro- and
macro-evolution? Is the question of inheritance settled? Where do evolutionary novelties come from? Oh, and what about ecology?
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The view from Altenberg:taking evo-bio seriously as a historical science,
the role of contingency
John Beatty
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The view from Altenberg:MS-based population genetic theory is limited
Sergey Gavrilets
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The view from Altenberg:multi-level selection theory
is here to stay
!z = cov (W, Z) + E cov (w, z)
(Price 1972)
collectivelevel
particlelevel
David S. Wilson
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The view from Altenberg:understanding the Genotype > Phenotype map
Genomic networks(less emphasis on
role of individual genes)
Greg Wray Michael Purugganan
Modularity,Evolvability and
evolutionary Robustness
Gunter Wagner
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The view from Altenberg:epigenetic and other inheritances
Genetic Epigenetic (methylation, iRNA,
histone conformation) Behavioral (mimicking) Cultural (traditions, memes)
Eva Jablonka
Eors Szathmary
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The view from Altenberg:niche construction & inheritance
John Odling-Smee
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The view from Altenberg: innovation, facilitated variation and the role of physico-chemistry
Gerd Muller Stuart NewmanMarc Kirschner
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The view from Altenberg:tempo and mode of macro-evolution
Phenotypicplasticity can catalyze
fast phenotypic shifts viaphenotypic / genetic
accommodation
Yours Truly
The predictive power of conventional short-term observations
is not strong over larger temporal and spatial scales ... Evolutionary
novelties originate non-randomly in space and time ... evolutionary
stasis ... species selection
David Jablonski
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The view from Altenberg:implications of and for philosophy of science
Werner KallebautAlan Love
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Is this a paradigm shift?
Thomas Kuhn
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Agency: Where natural selection acts (so-called units of selection problem).
Efficacy: The relative power of natural selection in comparison to other evolutionary mechanisms.
Scope: The degree to which natural selection can be extrapolated to macroevolutionary processes.
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An (extended) synthesis of what?
commondescent
naturalselection
Mendelism
population-statisticalgenetics
paleontology
naturalhistory
paleontology
evo-devogenomics,
networks theory
epigeneticinheritance
multilevelselection theory
evolvability &modularity
plasticity &accommodation
contingency
complexitytheory
nicheconstruction
ecology
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