DARWIN'S DANGEROUS IDEA: EVOLUTION AND THE MEANINGS OF LIFE

Twenty-five years ago Dan Dennett published this no-holds-barred, thorough philosophical analysis of both the sources of the extraordinary explanatory power of the modern Darwinian science of evolution and the sources of the persistent resistance of the anti-science opposition to it. To this day Dennett’s book remains the authoritative work on both of these subjects. As Dennett says in his introductory chapter, “In due course, the Darwinian Revolution will come to occupy a similarly secure and untroubled place in the minds – and hearts – of every educated person on the globe [as the Copernican Revolution does], but today, more than a century after Darwin’s death, we still have not come to terms with its mind-boggling implications.” To this end, Dennett unpacks for the reader the mechanics of the ‘Darwinian algorithmic process’ of ‘differential replication’ over time with occasional random mutations that environmental conditions winnow through natural selection. Dennett says, “This was Darwin’s great idea, not the idea of evolution, but the idea of evolution by natural selection.”The sources of the intense opposition to the idea of evolution by natural selection derive from the traditional notion that design and order MUST come from something conscious and intelligent, namely, Mind, which Dennett calls the ‘Cosmic Pyramid,' with God and Mind at the apex, and Chaos and Nothingness at the base. In contrast to this traditional picture, Dennett poses Darwin’s ‘inversion’ of this sequence in the form of a vast potential of biological possibilities that he calls ‘Design Space’ in which organisms progressively test mutations to their DNA and preserve any adaptations that prove useful against the crucible of natural selection. Each of these possibilities in Design Space is strictly generated by mechanical, biological means – without the assistance of ‘wonder tissue’ or ‘skyhooks’ that somehow magically produce the resulting organism – a non-miraculous account of “a massively parallel, and hence prodigiously wasteful, process of mindless, algorithmic design-trying, in which, however, the minimal increments of design have been thriftily husbanded, copied, and re-used over billions of years. The wonderful particularity or individuality of the creation was due, not to Shakespearean inventive genius, but to the incessant contributions of chance, a growing sequence of what Crick [who discovered DNA helix structure] has called ‘frozen accidents.’”Dennett says, “So Paley [an early critic of natural selection] was right in saying that Design took Intelligence. All he missed – and Darwin provided – was the idea that this Intelligence could be broken into bits so tiny and stupid that they didn’t count as intelligence at all, and then distributed through time and space in a gigantic, connected algorithmic process.”Dennett quotes a molecular biologist describing the biochemistry of an RNA phage replicating virus, then says, “Love it or hate it, phenomena like this exhibit the heart of the power of the Darwinian idea. An impersonal, unreflective, robotic, mindless little scrap of molecular machinery is the ultimate basis of all the agency, and hence meaning, and hence consciousness, in the universe.” This statement is the core of what is offensive to the ‘mind-first’ advocates, from devout religious evangelicals to theologians to sophisticated physicists to Marxist ideologues: no Supreme Mind, no Universal Consciousness, no Historical Force. Only mechanical, blind, intentionless material interactions.Dennett then addresses the objections of Gould and others to the method that biologists use to explicate the success of particular organisms in the vast Design Space of the Library of Mendel (all the possible DNA combinations of every organism): Adaptionism. What are the key environmental constraints on phenotypic expressions of all these vast possible mutations? Biologists seek to identify, by imagination, what possible adaptations that Mother Nature has chosen as the best, all things considered. Dennett then brings the sophisticated mathematics of John von Neumann’s game theory to bear on the thorny problem of identifying the environmental constraints on the differential replication of natural selection. How do organisms develop the ability to work in concert, to suppress the individual survivability of certain cells in a multi-cellular organism?These and other complex intellectual tools are exhaustively discussed and analyzed, including the ‘Life’ game devised by the mathematician John Conway and the ‘Baldwin effect’ identified by James Baldwin, and Dennett introduces them in a clear, straight-forward manner.If you want to understand the current state of the science of evolution by natural selection, then this classic book is required reading.

I bought this book in 1995 and really hated it. But ten years later I couldn't remember why I had such negative feelings about the argument, so I purchased another copy in 2006, but just got around to rereading it. It is a wonderful book, offering the beginning reader a mature exposition of basic evolutionary theory and the expert an insightful interpretation of recent controversies among biologists, often offering highly persuasive resolutions to arguments that have shed much more heat than light in the biology and philosophy journals. I cannot imagine the source of my earlier negative feelings, except perhaps his treatment of gene-culture interaction, to which I return below.One could summarize the interpretive part of the book by saying that in disputes between Richard Dawkins et al. on the one hand and Stephen Jay Gould et al. on the other, Dennett almost always sides with the former, supplying more cogent arguments than Dawkins himself, and aptly countering the latter, despite the brilliance of their argumentation. Most important, Dennett strongly defends an adaptationist view of evolution against the spandrels/just-so-stories critique as presented in the famous paper by Stephen Jay Gould and Richard C. Lewontin, "The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme", Proceedings of the Royal Society of London B 205 (1979):581-598. Dennett likens evolution to a nexus of algorithms, so that natural selection is a form of engineering. The interpretation of phenotypic characteristics as adaptations is then just a plausible form of "reverse engineering." Dennett thus asserts, correctly I believe, that "Gould and Lewontin's fabled refutation of adaptationism is an illusion." (p. 261).After dealing with the critique of adaptationism, Dennett devotes an additional chapter to Stephen Jay Gould's various other critiques of "Darwin fundamentalism," including Gould's critique of Darwinian gradualism and his "punctuated equilibrium" alternative. Gould's strategy in presenting iconoclastic alternatives was generally to write books and article for the general public rather than presenting detailed professional expositions in biology journals. This earned the ire of many academic biologists and paleontologists, and in the charged atmosphere created by Gould's attempt to "run around" the biological establishment, it was not surprising that the professional assessments of his arguments were generally negative and even derisive. Dennett in 1995 soberly and dispassionately reviews the evidence, uniformly to Gould's detriment. I believe more recent evidence is even more hostile to Gould's various claims. Steven Jay Gould was a brilliant and talented biologist, but not the radical innovator he so desperately desired to be.Dennett is especially critical of Gould's critique of the "gene's-eye view" of evolution as presented in Dawkins' brilliant The Selfish Gene (1976). Dennett defends Dawkins exposition of gene-centered evolutionary theory, but argues that Dawkins' inference concerning human altruism and cultural malleability are severely overdrawn. He then draws on Dawkins' argument concerning "memes" in The Extended Phenotype" (1982) to make the case that the gene's-eye view in the case of humans does not have the depressing right-wing implications Dawkins relishes in espousing in The Selfish Gene. A more modern argument is that gene-level selection, individual-level selection, and even group-selection models will all give the same answer if the proper accounting relationships are obeyed. The difference among the three approaches is that for different analytical purposes, one or another of the three approaches may be simpler and more insightful. For instance, in social species the structure of social life becomes a key contributor to the enhanced fitness of group members, so that a multi-level selection approach in which the accounting relations take the costs and benefits of behavior to be a function of social organization is more insightful than a lower-level approach that simply takes the costs and benefits as given.Dennett also has a careful chapter in which he shows that Dawkins' concept of a meme can be used as a counterbalance to a purely genetic approach to human evolution. "The primary difference between our species and all others," he reports, "is our reliance on cultural transmission of information, and hence on cultural evolution. The unit of cultural evolution, Dawkins' meme, has a powerful and underappreciated role to play in our analysis of the human sphere." (331)I think the meme concept is a loser because it is too detached from the gene concept to render a mimetic analysis evolutionarily coherent. The correct theory is that of gene-culture coevolution, as developed by several authors, including Cavalli-Sforza and Feldman: Marcus W. Feldman and Luigi Luca Cavalli-Sforza, "Cultural and Biological Evolutionary Processes, Selection for a Trait under Complex Transmission", Theoretical Population Biology 9,2 (1976):238-259, .Luigi Luca Cavalli-Sforza and Marcus W. Feldman, Cultural Transmission and Evolution (Princeton, NJ: Princeton University Press, 1981), Boyd and Richerson: Robert Boyd and Peter J. Richerson, Culture and the Evolutionary Process (Chicago: University of Chicago Press, 1985) and Dunbar: Robin M. Dunbar, Grooming, Gossip, and the Evolution of Language (Cambridge, MA: Harvard University Press, 1996). Unfortunately, and inexplicably, the names of these authors do not even appear in the text or bibliography.

Ordered Dennetts other works immediately!

Book are good

I have found this book pretty boring, lacking focus, full of lengthy And pompous digressions. I was continuously asking myself: what’s the point the author is trying to make, if any? Where is he trying to lead the reader? I was not able to figure out what I was learning from it. Was not able to finish it.

This book gave an excellent summary of contemporary evolution theory to date, and has interesting and insightful commentary on cultural evolution, going into how man is able to act as (yet another) 'crane' to an ongoing evolutionary process.It provides an opportunity to think about what we mean by 'natural' (a word banded around perhaps too freely today), and whether our technologies and impact on other species evolution fit into what was already taking place.In places, particularly the discourse on Gould in chapter 10, it can be a bit overly wordy. However, overall it is an excellent and stimulating read.

Não é um livro fácil de ler, então você precisará dedicar um bom tempo para refletir sobre as informações trazidas pelo autor. Também não é uma obra imparcial. Daniel Dennett traz a sua visão de biologia evolutiva ao mesmo tempo que desconstrói visões diferentes, tudo feito de forma muito inteligente e logicamente bem amarrada. Além das discussões gerais, o texto apresenta a Teoria da Evolução como um algoritmo, e a ideia é bem interessante e plausível, apesar de possuir opositores. Para quem quiser se aprofundar nas discussões acerca da Teoria da Evolução é uma obra muito valiosa. Devido à densidade dos assuntos, o livro pode ser entediante em alguns momentos, mesmo assim, é uma obra que vale a pena ser avaliada por pessoas que queiram se aprofundar nas discussões que surgem em torno da ideia perigosa de Darwin!