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Steven H Propp
- Publié sur Amazon.com
Stephen Jay Gould (1941-2002) wrote many other important books, such as Ontogeny and Phylogeny, Ever Since Darwin, The Panda's Thumb, Hen's Teeth and Horse's Toes, The Flamingo's Smile, Wonderful Life: The Burgess Shale and the Nature of History, Eight Little Piggies, Dinosaur in a Haystack, The Lying Stones Of Marrakech, etc.
He wrote in the first chapter of this 2002 book, "This book asserts, as its key premise and one long argument, that such an understanding of modern evolutionary theory places the subject... with the central core of Darwinian logic sufficiently intact to maintain continuity as the centerpiece of the entire field, but with enough important changes ... to alter the structure of evolutionary theory into something truly different by expansion, addition, and redefinition. In short, 'The structure of evolutionary theory' combines enough stability for coherence with enough change to keep any keen mind in a perpetual mode of search and challenge." (Pg. 6) Later, he summarizes, "This book presents, as its primary thesis, the notion that (i) Darwinism may be viewed as a platform with a tripod of essential support; (ii) each leg of the tripod now faces a serious reforming critique acting more as an auxiliary than an alternative formulation; and (iii) the three critiques hold strong elements in common, and may lead to a fundamentally revised evolutionary theory with a retained Darwinian core." (Pg. 166)
He reveals, "Far more than most colleagues, I have tended to work alone in my professional life and publication. But for each of the conceptually difficult and intellectually manifold issues of reevaluation of the central logic of the three essentially Darwinian postulates, I desperately needed advice, different skills... from colleagues who complemented my limited expertise with their equally centered specialties and aptitudes... Thus... I worked with Niles Eldredge on punctuated equilibrium..." (Pg. 27) Later, he explains, "I wrote most of our 1972 paper, and I did coin the term punctuated equilibrium---but the basic structure of the theory belongs to Eldredge, with priority established in his 1971 paper." (Pg. 775) Later, he rejects the argument that "I advanced punctuated equilibrium in order to foster a personal political agenda [i.e., Marxism]. I resent this absurd misreading... I said nothing about my political beliefs ... a private matter that I do not choose to discuss in this forum." (Pg. 1018)
He suggests, "the theory of natural selection is, in essence, Adam Smith's economics transferred to nature." (Pg. 122) He adds, "By interpreting Darwin's radical theory as a response to [William] Paley... based on an importation of the central argument from Adam Smith's laissez-faire economics, I believe that we achieve our best insight into the essential claims of Darwinism and natural selection." (Pg. 124-125) He asks, "Does Darwinism truly require the following extreme formulation: 'Natural selection can only act by the preservation and accumulation of infinitesimally small inherited modifications.' At some level of discontinuity, of course, Darwin's strong statement must prevail... But can we justify Darwin's application of the same claim to single organs? Suppose (as must often happen) that developmental heterochrony produces a major shift in form and function by two or three steps without intermediary stages. The size of these steps may lie outside the 'normal' variation of most populations at most moments, but not beyond the potential of an inherited developmental program." (Pg. 150-151) He wonders, "what conceivable pressure of natural selection could account for gradual stages in the disappearance of a functionless organ---for the loss of function should remove a structure from the domain of selection entirely, and knowledge about an eventually adaptive state could not be invoked to guide an explanation for intermediary stages along such a functionless path." (Pg. 203)
He criticizes Richard Dawkins: "Dawkins's first book says, in no uncertain terms... that genes are exclusive units of selection... and that bodies... cannot play such a role. The second book says that we can view evolution equally well from either the gene's or the organism's point of view, [although] Dawkins still prefers genes... These two positions connote... mutually exclusive, accounts of causality in evolution... I do not know why Dawkins altered his view so radically. But may I suggest that he simply could not... maintain full allegiance to the fallacious argument of strict gene selectionism. Dawkins... ultimately needed to make so many statements from the organism's point of view that he must have begun to wonder whether he could really continue to regard such organismal language a mere convenience, while touting the genic formulation as a unique reality... With such an admission, the selfish gene becomes an impotent meme." (Pg. 641)
He explains, "By 'random'... I only mean to assert the hypothesis of no overall preference for increasing complexity ... a system in which each speciation event has an equal probability of leading either to greater or to lesser complexity from the ancestral design... the overall system (all of life, that is) need not display any overall bias---for just as many individual lineages may become less complex for equally adaptive reasons. In a world where so many parasitic species usually exhibit less complexity than their freeliving ancestors, and where no obvious argument exists for a contrary trend in any equally large guild, why should we target increasing complexity as a favored hypothesis for a general pattern in the history of life?" (Pg. 900)
He argues, "Yes, five percent of a wing offers no conceivable aerodynamic benefit, and could not therefore be formed, or converted into a full wing, under a smooth regime of natural selection FOR FLIGHT. But sequences forged by selection only presuppose continuity in differential reproductive success, not continuity in a single function. Thus, the incipient stages may have performed a different function, for which their 5 percent of a wing imparted benefits. Eventually, the enlarging proto-wing entered the domain of aerodynamic benefit, and the original function changed to the primary utility now exploited by birds. Current function cannot be equated with reasons for historical origin." (Pg. 1223) But he adds, "natural selection cannot act as a magic wand for a immediate construction of any urgent need... a large component of evolvability must be attributed to inherent structural properties of features that ... manifest a capacity for subsequent recruitment (with minimal change) to substantially different and novel functions. The study ... of these formal and structural reasons for evolvability sets an important agenda, now largely unfilled but attracting considerable interest, for evolutionary biology." (Pg. 1228)
He concludes, "This book attempts to expand and alter the premises of Darwinism, in order to build an enlarged and distinctive evolutionary theory that, while remaining within ... Darwinian argument, can also explain a wide range of macroevolutionary phenomena lying outside the explanatory power of extrapolated modes and mechanisms of microevolution... (1) punctuated equilibrium establishes... a general speciational theory of cladal trending... (2) catastrophic mass extinction ... suggests a general theory of faunal coordination far in excess... of what Darwinian microevolutionary assumptions about the independent history of lineages under competitive models of natural selection could possibly generate." (Pg. 1339-1340)
Besides being a highly creative evolutionary theorist, Gould was also a brilliant writer and an engaged "public intellectual." His presence is sorely missed on the scientific and literary scene.
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Jim Blake, Jr.
- Publié sur Amazon.com
Format: Format Kindle
This book should have been called “Deconstructing Darwin” or “The Structure of My Evolutionary Theory”. Gould was reluctant to give ammo to Creationists and his ego was monumental but not so big that he wished to be seen by colleagues overtly replacing a towering cultural icon with himself. Nonetheless, Gould uses 1,343 pages to kneecap Darwin, apologizing, pussy-footing, hemming, hawing and aw-shucksing throughout as he tries to kill the great precursor- a tortured psycho- drama worthy of Dostoevsky, a Freudian case study of Oedipal contortion or an essay by Harold Bloom.
Gould uses 1,343 pages to create a structure that might support his bold assertions contradicting three key elements of Darwin’s iconic masterpiece “The Evolution of Species” The foundation of Gould’s ambitious edifice is an account of 150 years of evolutionary theory, easily worth the price of the book, lucid, fascinating, detailed, erudite. In part one of two parts, Gould lays this broad foundation of late 19th and 20th century ideas, many running counter to doctrines of a strict Darwinism that, though showing signs of wear, remains lodged in the Modern zeitgeist. SJG’s rationale for examining the history of so many ideas no longer receiving traction during much of the 20th century up to his own career, serves as building blocks for SJG’s grand theoretical swerve away from Charles Darwin. SJG revives key features of once dismissed evolutionary thinking. Marginalized thought is re-animated by
SJG to reflect 40 years of genetic research. In his effort to re-write Darwinian causality SJG uses diverse heuristic strategies from the philosophy he majored in as an undergraduate, the paleontology he built his early scientific career upon, to history, religion, literature and several branches of bio-science.
In two nutshells: first Darwin then Gould’s “apostasy”:
Darwin’s three theoretical branches beyond the main trunk of Darwin’s theory tree, that organisms evolve at all, are as follows: 1. Species evolve gradually and continuously in very small increments over the wide expanse of an epoch(s) Any change whatsoever will be insensible in a dozen or even a thousand human lifetimes. 2. Species evolve due to natural selection ( survival of the fittest and weirdest) caused by forces external to the individual. These external forces of causation act upon mutations manifest in individual organisms. These external forces of selection are: A. competition within species for sexual access B. adjusting ( or not ) to climate C. competition with other organisms in its ecosystem for food and dominance. 3. The primary taxonomic level in a hierarchy of causation for plant and animal evolution is the individual organism, not down a level to the gene (Dawkins) or up a taxonomic level, or three, to the species, clade or the phylum (Gould).
SJG, on the strength of the Niles Eldredge-SJG theory of Punctuated Equilibrium along with 40 years of genetic research done by others, has denied, demoted, contradicted Darwin: 1. Evolution is characterized by punctuated equilibrium, short periods of speciation ( great change) followed by eons of stasis. Evidence described in hundreds of published scientific experiments and exploration during past 50 years. There do exist species that evolve gradually, but most, as seen in the 350 million year fossil record, do not. 2. It has been proven by genetic research of the past thirty years that the bulk of our genome has been chemically locked into its chromosomal place for many millions of years. Humans share genetic sequences for metabolism and organ development with many chordates, vertebrates, mammals and especially primates. Very little of our genome is available for Darwin’s version of natural selection. The majority of genetic change is internally driven by genetic and physical constraint, not driven by forces external to the individual, as Darwin asserted. 3. The individual is not the primary causal level, in the Linnaean taxonomy, for natural selection. Gould and others assert that the key entity in the evolutionary drama is the species not the individual. Entire species survive and diversify or become extinct in response to rare catastrophic forces of climate change, bolide ( comet, meteor, asteroid) impact and or plate tectonic effects on ocean currents, weather patterns and vegetation growth as continents shift.
After ten weeks of enjoyment working my way slowly through this non-edited ( if only it were poorly edited) but intensely engaging manuscript bristling with drama, hard science, truthy science, petty bickering, axe-grinding, Shakespearian and Biblical erudition, I conclude the following:
1. This is a great book on any terms, forgiving its bloviation and inexplicable levels of repetition, it is easily the most intellectually stimulating book I have ever read. So much fun to engage in conversation / battle with author on most every page, filling margins, taking more than a hundred pages of notes.
2.The first 585 pages are the deeply fascinating history of evolutionary theory per book title - the remaining 758 pages is a turgid, clotted, repetitious, weed-addled case for kneecapping Darwin while issuing a continuous stream of obsequious, deferential encomiums to this now untouchable ( lest one fuel Creationism) icon.
3.Much of SJG’s evidence for his cornerstone of De-Darwining - his theory of Punctuated Equilibrium is scientific papers ( many his own) on mollusk fossils many of which are pelagic neonates
4.SJG analyzes, in excruciating detail, the “evolution” or lack thereof of fossils in a given deep boring or sample of strata ignoring the possibility that the species he has observed as a single one through millions of years, could easily have floated into his field of study from left field ( cue: Beach Boys hit song “Kokomo”)
5.SJG’s assertion that the species is the key causal taxonomic level reads more like a jealous rebuke to nemesis Richard Dawkins in response to RD’s very popular 1978 book “The Selfish Gene”. After dozens and dozens of pages of SJG hammering away at RD ( reader screaming for an editor here) OK, we get it. SJG’s species level has its role as does Darwin’s preferred level, the individual. SJG’s case for the primacy of the species, though interesting and well documented is not convincing.
6.SJG’s sawing away at thrid leg of Darwin’s three-legged theory - that natural selection is externally driven not internal, is the most viable of SJG’s three points of glorious contention.Gould’s scientific evidence from an array of geneticists is fascinating and a worthy candidate for amending the Modern Synthesis.
7.One out of three ain't bad and hats off for Punct. Equilibrum, a theory that opened a lot of minds. There must be better evidence than the studies shown in this book for such a cool swerve from Darwin’s gradualism.
8.SJG knew he was dying of cancer when he wrote the second half of this book. He smoked a lot of weed to kill his pain. Although it was fun to note in margin when the smoke dominated clear thinking and writing, rewriting and editing it probably wasn’t polite. All-in-all, a grrrr-eat book. I love it. It comes across more like a Russian novel or “Moby Dick” with Darwin as leviathan than a science book. I got deep enjoyment from every one of the 500 hours I spent reading it. I’m going to miss it.
9.Don’t miss the Jim Blake ( aka: Harlan James) essay, inspired by TSOET “The Ugly Gene-Hardwired for Banality” coming soon to e-books.