Read Ebook {PDF EPUB} Dawkins vs Gould Survival of the Fittest by Kim Sterelny Kim Sterelny’s Dawkins vs. Gould: Survival of the Fittest. It isn’t worth my while to debate every ambitious Darwinist who wants to try hard at ridiculing the opposition, so my general policy is that Darwinists have to put a significant figure at risk before I will agree to a debate. That means specifically [Richard] Dawkins or [Stephen Jay] Gould, or someone of like stature and public visibility. So wrote Phillip E. Johnson, former University of California at Berkeley law professor and founder of the “Intelligent Design” movement, in April 2001. Had either Dawkins or Gould met his challenge, it would have been a coup for the then-decade-old movement. After all, such well- respected minds would only entertain the most serious of challenges. Intelligent Design (ID) theorists could therefore claim some measure of victory by having the debate at all; however, because of their respective pedigrees, Dawkins or Gould would be held to higher standards. For precisely that reason, the two biologists resolved to deny Johnson and his supporters their desired platform: in a draft of an open letter to be co-signed by Gould, Dawkins responded, “. we shall cultivate our evolutionary gardens, occasionally engaging in the more exacting and worthwhile task of debating each other.” (This episode is recounted in Dawkins’ collection of short works, “A Devil’s Chaplain,” in the essay entitled “Unfinished Correspondence with a Darwinian Heavyweight.”) The task may not only be an exacting and worthwhile one, but also one to inflame intellectual passions and fuel an academic rivalry. The history of science—which is, after all, a history of all-too-human scientists—is replete with conflict. Recall how Newton antagonized Leibniz over the nature of space; imagine how the sparks must have flown when Einstein took Bohr and his nascent quantum theory to task. When it was at its most heated, the feud between Dawkins and Gould was waged as publicly as scientific debate may be. Their exchanges played out in the pages of such widely circulated periodicals as the New York Review of Books , to say nothing of each theorist’s own best-selling popular works. As a result, even a marginally informed layperson would have been aware of the debate’s existence, if not its details. Unfortunately, it is in the details that the Dawkins–Gould debate differs from those other well-known academic feuds, and this has been a source of trouble for evolutionary biology in general. The popular model of a scientific debate is that of a zero-sum game: The triumph of one party demands repudiation of the other. Space and time are either absolute quantities or not; quantum mechanics is either true or false. It is perhaps for this reason that Johnson and his Intelligent Design ilk have placed so much emphasis on Dawkins and Gould. After all, if one well-respected biologist follows Darwin and another equally well-respected biologist disagrees with the first, then there can hardly be consensus about the validity of evolutionary theory. Nevertheless, the exchange between Dawkins and Gould does not fit this misconceived winner-takes-all form. It is therefore to his credit that Kim Sterelny opens his survey of the debate, entitled Dawkins vs. Gould: Survival of the Fittest , with an explanation of what Dawkins and Gould hold in common, proceeding to what is at stake for the opponents only after laying out what is taken for granted. Both are avowed disciples of Darwin and his theory of evolution by means of natural selection. Both have defended the idea that, within any population whose reproductive rate outstrips its means of survival, advantageous traits inherited genetically will tend to be preserved. Both agree that, given a geological timescale, these preserved traits will eventually accumulate in new forms of life. Where the two differ is in their interpretations of natural selection’s scope and meaning. Proceeding through Dawkins vs. Gould one may be struck by how often these antagonists (described in the book’s back cover as being engaged in a “savage battle”) accommodate one another. With few exceptions, each chapter follows a similar pattern: a summary of the biological facts followed by a survey of the combatants’ common ground and the point of departure taken by one from the other. Far from homogenizing the titular figures, however, this approach ultimately serves to give a clear summary of the distinct intellectual spaces they occupy. Those readers who enter into the text lacking knowledge of either figure’s works will find excellent summaries of the broad trends in each career. What follows is a sort of “greatest hits” compilation. From The Selfish Gene , The Extended Phenotype and The Blind Watchmaker Sterelny draws out the concepts central to Dawkins’ view of biology. Dawkins has built his career upon the foundations of his selfish gene theory, wherein biology is cast as a mechanistic system similar to one of the physical sciences. The treatment given in this paper illustrates how it is possible that even the most complex organic traits might be explained in terms of the slow, steady action of simple laws (natural selection) upon the system’s most basic components (genes). This so-called gene’s eye view of evolution is contrasted with that of Gould, as distilled from such works as Wonderful Life , Full House , and The Structure of Evolutionary Theory. Gould’s central themes of contingency and diversity create a view of biology in which the constant pace of natural selection may be perturbed by the vagaries of a chaotic environment. Whereas the nuance of Gould’s evolutionary theory might come across as more complicated than Dawkins’ to a neophyte, Sterelny keeps his descriptions of each concept as clear and uncomplicated as possible. Sterelny’s success in isolating the essential points of contention between Dawkins and Gould follows from an important insight into their debate: It is, for the most part, less over science than it is over philosophy (it comes as no surprise that Sterelny is himself a professor of philosophy at Victoria University in Wellington). He writes that the arguments between the two “within evolutionary theory are exacerbated by different assessments of science itself” (p. 14). Dawkins, the consummate Oxford scientist, sees science as an all-encompassing reductionist program; Gould, a polymath equally comfortable writing about such disparate subjects as DiMaggio-era baseball and Cambrian-era trilobites, takes a more limited view of science as on a par with other modes of knowledge. This dichotomy, as drawn by Sterelny, is largely accurate but has the potential to ultimately become a part of a larger problem. At one point he writes that Gould built his career “arguing for the existence of large-scale patterns…not explained by natural selection” (p.79). One will never find in Gould’s work the claim that natural selection is insufficient to the task of explaining biological phenomena. Rather, Gould’s emphasis is on the claim that its sufficiency ought not to be overextended to explain phenomena for which it is unnecessary; he often cautions against thinking of all organic properties as adaptive. Sterelny does consider these ideas, particularly in his chapter entitled “Selection and Adaptation,” but mostly as contrasted with the “adaptationist” leanings of the “ultra-Darwinist” Dawkins. If this is the sort of locution that might inspire pumped fists and gleeful cheers from the aforementioned Intelligent Design theorists, it is only because it is so easily misread. Perhaps, because of the summary nature of his survey, Sterelny sometimes seems to cast Dawkins and Gould in the roles created for them in the ID misrepresentation of their debate, despite his efforts to paint both biologists with the same Darwinian brush. In particular, to cast Gould as opposed to some ‘ultra-Darwinian’ orthodoxy, absent the proper context, has the potential to lead to such foolishness as that found on Creationist websites that claim Gould as a closeted champion of their cause. Dawkins is only more Darwinian than Gould insofar as he is more Darwinian than Darwin himself; where the father of modern biology saw natural selection as the “main but not exclusive” mechanism for evolutionary change (as written in The Origin of Species ), Dawkins sees selection as an agent that is both exclusive and universal. Gould’s rejection of this extension of Darwin’s theory does not entail rejection of that theory’s core. The absence of this explicit clarification from Sterelny’s book may lead to misunderstanding for those readers whose preconceptions of this debate have been shaped by a media uncritical of the ID theorists’ account. This is a minor issue overall; however, given the historical context of the relevant debate, it is one that the lay reader ought to bear in mind. Notwithstanding this fault, Sterelny’s Dawkins vs. Gould is a worthwhile read on several levels. For those whose interest in evolutionary biology has not yet carried them into the field’s contemporary discourse, the book not only gives a clear and accurate summary of the subjects’ corpora but also points the way towards where to turn next. Sterelny’s extensive list of suggested readings should also prove useful to more advanced readers, many of whom will benefit from the conceptual clarity provided by Sterelny’s review of the material. Even as the titular clash of personalities has, sadly, had its final chapter written, Sterelny’s book should serve as the starting point for those inspired to carry on the clash of ideas. Book Review: Kim Sterelny, Dawkins vs. Gould: Survival of the Fittest (Cambridge, UK: Totem Books 2007). 205 pp. Kenneth W. Krause is a contributing editor and “Science Watch” columnist for the Skeptical Inquirer. Formerly a contributing editor and books columnist for the Humanist , Kenneth contributes regularly to Skeptic as well. He may be contacted at [email protected] . All too often lost among the mind-numbing, carnivalesque creationist-vs.-evolutionist sideshows currently haunting the pop media’s pseudo- intellectual backwaters are the genuinely scientific debates over evolution’s varied mechanisms and alleged limitations. What is the fundamental unit of evolutionary change? Is the process dominated by natural selection, developmental constraint, or chance? To what extent can selection explain and predict cultural and psychological phenomena? No questions could be more relevant to, among other things, a competent understanding of humanity—who we are and what we can reasonably expect from one another. And these are precisely the questions presented and debated among science’s most prolific authorities in philosopher Kim Sterelny’s updated edition of Dawkins vs. Gould . Oxford zoologist, Richard Dawkins, and recently deceased Harvard paleontologist, Stephen Jay Gould, of course, agreed more than disagreed on almost every aspect of evolution. Dawkins, for example, never proposed that the effects of natural selection were limited to gene frequencies. Nor has he denied the essential role of organisms. Instead, Dawkins pointed out that because adaptations result only from extended series of small changes, the basic agents of evolution must persist over extended periods of time. At the organismal level, however, sexual reproduction is not the same as duplication. Only the gene (defined in The Selfish Gene as “any portion of chromosomal material that potentially lasts for enough generations to serve as a unit of natural selection”) is significant enough to cause change, on the one hand, and small enough to escape DNA recombination, on the other. Only gene lineages, in other words, possess histories deep enough to serve as the fundamental units of natural selection. To the organism, Dawkins relegated the substantial but secondary role of “survival machine” for genes or, more accurately, gene alliances. Gould’s view was more traditional in Darwinian terms and perhaps more intuitive. Although he acknowledged the fact of selection at the genetic level, for him such was the exception to the general rule that evolution mostly acts upon organisms in local populations, or even on groups of organisms including species and clades (founding species and all their descendents). Genes more record the process than cause it, Gould argued, and their survival relies not simply on alliances with other genes, but more profoundly on various features of and modifications to the organism’s larger environment. Dawkins, however, has alluded to at least two general phenomena demonstrating the considerable weakness of any organism-centered view of evolution. “Outlaw genes,” for example, rather than allying with other genes, appear to compete against them—potentially at the expense of the host organism’s fitness. Consider mitochondria, for example, which are inherited only maternally. Certain plants that are normally capable of producing both pollen and seed will occasionally develop “sex ratio distorter genes” causing organisms to produce only mitochondria carrying seed. Any mutation to such genes rendering daughter-making more likely would be favored, everything else being equal. Similarly, so-called “segregation distorter genes” will chemically sabotage the allele with which they are paired on the chromosome, even if it results in a less fit—in this case sterile—organism. Other genes promote themselves by reaching beyond the organism’s physical margins. Recently, in The God Delusion , Dawkins reiterated how this works from the perspective of a living extended phenotype. “An animal’s behavior” he writes, “tends to maximize the survival of genes for that behavior whether or not those genes happen to be in the body of the particular animal performing it.” The classic example involves a parasitic brainworm that burrows into the head of an ant, causing it to climb toward the most exposed portions of leaves and blades of grass until a cow, the worm’s ultimate host, consumes it. Although the relevant genes reside in the parasite, their adaptive effect takes place in its host. Instead of adapting the organism to the environment, in broader terms, extended phenotype genes adapt the environment to the organism. As such, neither outlaws nor extended phenotypes can be comfortably fused into an organism-centered view of evolution, and for Sterelny, Dawkins’ reductive selfish gene theory of natural selection is therefore the more sustainable one. But Gould, of course, de-emphasized the consequence of natural selection in the first place. For example, although both he and Dawkins recognized the supply of variation as a constraint on the evolutionary trajectory of any given population, Gould conceived of developmental biology as a brake on creativity or as an entrenchment of evolutionary patterns and features. Consider, for instance, Wallace Arthur’s study of two centipede families. Each of the 1000 or so species of Geophilomorphians display an odd number of body segments (every one of which has a pair of legs), though that number ranges outrageously from 29 to 191. A similar diversity of Lithobiomorphian species all have fifteen segments. Why no even numbers? Selective pressure is an unlikely answer, given the extreme range of leg pairs among Geophilomorphians. In his Biased Embryos and Evolution , Arthur concluded that nature is incapable of selecting a Lithobiomorphian with, say, thirty segments because these creatures’ developmental mechanisms impose an absolute constraint against it. He pointed out as well that more relative biases in the variation reserve are sufficient to the same task. Sterelny offers a hypothetical, initially isolated population of ringtail possums the average weight of which is two kilograms. Comparatively sized predatory cats are introduced. One-kilo possums can hide; three-kilo possums can successfully defend themselves. All other factors being equal, which will be selected? The answer, Sterelny reasons, will depend not on external dynamics, but rather on the current possum population’s developmental bias. Consider too one of Dawkins’ own examples in Climbing Mount Improbable . In general, shells vary in only one of three ways: their “flare” (the rates at which they uncoil in one plane), their “spire” (the rate at which they rise above that plane), and their “verm” (the rate at which their tube expands). Such dimensions allowed David M. Raup to represent the range of all possible shell variations as a cube (dubbed “Raup’s cube”), much of which remained unoccupied by a shaded area indicating existing shell shapes. Why so many missing variants? Have existing shells inherited an insufficient capacity to vary, or has selection determined the outcome? We simply don’t know yet, according to Sterelny. But Dawkins has emphasized the revolutionary rather than the conservative character of developmental biology. In Climbing Mount Improbable , he argued that, for the relevant lineages, the momentous invention of segmentation, for example, opened up an expansive new world of adaptive possibilities. Indeed, segmented arthropods, including spiders, crabs, and insects, are by far the most diverse group of animals on the planet. While Sterelny admits that “[t]he integration of evolution and development is the hottest of hot topics in contemporary evolutionary theory,” his “best current guess” is that developmental biology does indeed produce significant biases in the variation available for natural selection. In support of his position, he points out that gene mutations involve movements, duplications, inversions, and deletions in addition to limited point mutations. These “middle-size” mutations cause changes to gene regulation, shifts in reading frames, and thus substantial alterations to traits that might well introduce variation supply biases. Touting his Ontogeny and Phylogeny as a “foundation of modern evolutionary developmental biology,” Sterelny predicts that Gould’s position in this regard “will probably be vindicated.” So too does the author prefer Gould’s accent on the caprice of mass extinctions along with its implied, attendant claim that such calamities are qualitatively distinct from run-of-the-mill background extinctions. Recently, some have suggested that certain so-called mass events had actually resulted from routine climate change, competition, or merely localized bad luck. Much debate in particular has centered on the Cretaceous/Tertiary boundary 65 million years ago. Skeptics of the meteor impact’s significance wonder why crocodiles, turtles, and frogs survived while dinosaurs (excepting birds), pterosaurs, pliosaurs, and other marine reptiles did not, arguing that some such creatures had dwindled or even gone extinct prior to the impact. Ever the committed fossil hunter, however, Gould highlighted the 570 million year old remains of the frond- and disc-shaped Ediacaran fauna (perhaps more akin to lichens than animals, according to others), their abrupt disappearance following the start of the Cambrian Period 543 million years ago, and the ensuing “explosion” of fossil evidence documenting the emergence of today’s major lineages. Similarly, Sterelny underscores the catastrophe that devastated 90 percent of animal species at the close of the Permian Period 251 million years ago. Again, although he certainly acknowledges the fact of mass extinction, Dawkins has demoted these events to simple interruptions in the omnipresent process of selection. For Gould, by contrast, such chance calamities were paramount, dealing the death card to some groups and a royal flush to others. But the most incisive fissure between these two men opened over the relentlessly messy subject of human behavior. Gould savagely opposed sociobiology and, perhaps to a lesser extent, its descendant, evolutionary psychology, insofar as they presumed selective underpinnings. On the one hand, Randy Thornhill’s hypothesis that, under certain circumstances, sexually isolated men can improve their reproductive fitness through rape is easily criticized for its failure to consider, among other things, the obvious social costs of violence. On the other hand, Gould found adaptive theories of differential parental investment more promising. Some emotional propensities common to men and women, he suggested, might well be adaptive, given that males find advantage in spreading their sperm as widely as possible and that females are most successful when able to extract additional time, investment, and attention from males. Even so, Gould warned, the range of behaviors that can be explained in such Darwinian terms was severely limited. Although Dawkins employed certain tools distinct from those standard to most sociobiologists and evolutionary psychologists—the meme in particular—he has remained steadfast in his commitment to the evolutionary paradigm as the optimal strategy for understanding human behavior— an important observation that inevitably leads us to a more heady and comprehensive evaluation of this classic intellectual clash. In some ways, Gould seemed to fear what he imagined to be science’s potentially injurious stabs into the soft, sensitive underbelly of human existence. Dawkins, by contrast, seems to fear almost nothing. Indeed, he manages to maintain a contagious optimism over the tender topics of sociality and morality precisely because he recognizes, first, that science is far and away the best if not the only honest and practical method of discovering truth, and, second, that the more fortunate realities of our evolved behavior—specifically the fact of cooperation—are both liberating and hopeful. In the end, Sterelny agrees more with Dawkins, and, despite a deep and humbling appreciating of Gould’s extraordinary talents and accomplishments, so do I. Had I not felt much as Dawkins apparently does, after all, I probably wouldn’t have bothered to write this article. Dawkins vs. Gould : Survival of the Fittest. Sign up for LibraryThing to find out whether you'll like this book. No current Talk conversations about this book. This book is just what the title says, a summary of the views of Dawkins and Gould, with focus on controversial areas. The two biologists were (Gould died not long after this book was published) engaged in public and not always civil disagreement over issues that to the casual observer might not seem to warrant intense emotion. This book has been criticized for not including the verbal exchanges, which would be more entertaining than summaries, but that's its purpose -- stripped of ego and emotion, what are these guys actually arguing about, and why does it matter? (read 24 Mar 2009) Given that it covers a particularly vitriolic skirmish between two huge, polarising and consistently outspoken opposing generals in the Science Wars, Kim Sterelny had on his hands a fascinating topic. He quite easily could have crammed this brief volume full of the proverbial sizzling gypsies - gory details of the academic handbags which were exchanged in full view of an admiring dilettante public - but inexplicably, he chose not to. Instead, the fieriest debate is reduced to its desiccated intellectual premises and is presented worthily and dryly. This is, no doubt, second nature to a professional scientist like Sterelny, but it displays a lack of worldliness for an aspiring popular author; a worldliness, ironically enough, possessed in oodles by both of his subjects. Unlike your usual zoologist (though granted, I don't know that many), Richard Dawkins invites extremes of adoration or vitriol from just about anyone who's heard of him (and, given his gift for self publicity, that's most people); The late Steve Gould was (on this side of the ditch at any rate) of less general reknown but equally susceptible, in the right circles, to excitable opinion. Dawkins the zoologist is a crusading atheist - irony intended - and devoted son of the enlightenment; Gould the paleontologist was possessor of a more open-minded view on woolly artsy pursuits like religion, literature and architecture, allowing them to bleed into his professional scientific opinion in a way that horrified the purist in Dawkins. Also, apparently, Gould was a Marxist. Battle lines accordingly drawn. Now, to his (professional, if not authorial) credit, Sterelny abstains from addressing Gould's politics, and instead succinctly and patiently outlines the camps' respective differences in evolutionary theory - differences which are relatively subtle to non specialists, truth be told - but (no doubt being a good scientific chap - clean fight, fair play and all that) refrains from descending into the real particulars of the debate, in particular referring only in passing to a petulant and protracted exchange in the New York review of books following publication of Daniel Dennett's Dawkinsesque Darwin's Dangerous Idea. (How about that for a bit of alliteration, by the way). Such noble dispassion is a mistake, in this reviewer's opinion, for it neuters a book which, had it been rendered breathlessly enough, could have been a rip-snorter. If it were me I would have extracted much of the debate in full and provided some journalistic context around how it came about, and certainly extracted some of the peachier exchanges. For example, how about this one: "[Dennett's] limited and superficial book reads like a caricature of a caricature--for if Richard Dawkins has trivialized Darwin's richness by adhering to the strictest form of adaptationist argument in a maximally reductionist mode, then Dennett, as Dawkins's publicist, manages to convert an already vitiated and improbable account into an even more simplistic and uncompromising doctrine. If history, as often noted, replays grandeurs as farces, and if T.H. Huxley truly acted as "Darwin's bulldog," then it is hard to resist thinking of Dennett, in this book, as "Dawkins's lapdog." Cracking stuff - but it finds no place in Sterelny's volume, and I had to look it up online (it, and the whole vituperative article from which it came, is reproduced at the New York Review of Books' website.) Sterelny's main problem seems to be that he is such a frightfully good egg he can't bring himself to dramatise proceedings, which are screaming out for it, at all. He confesses an intellectual kinmship with Dawkins but then is so scrupulously fair to Gould in his assessment of their competing arguments that it is hard to comprehend what he even sees in Dawkins' view. That might be my bias: while much taken by Dawkins' and Dennett's books when I first read them, I have found more resonance in Gould's humanist, pragmatic view the more I've read of it (and the older I've got), so (as a point of disclosure) I come out on the other side of the argument to Sterelny. That's not my problem with his book; however, quite the opposite: it's the very bloodlessness of it. ( ) Slim and readable. I had read all of Dawkins and nothing by Gould and saw this as a necessary scene setter before diving into Gould's work. It worked in this role very well by giving a great overview of the various areas of agreement and dispute. Easy to read for the non-specialist, I whizzed through it in an afternoon. A fantastic suggested reading section, split down by chapter and with quick summary reviews of the suggestions which also gives details of which are suitable for the non-technical reader. This section alone is almost worth the cover price. I added significant length to my wish list after reading this book. Dawkins vs. Gould : survival of the fittest. "Science has seen its fair share of punch-ups over the years, but one debate, in the field of biology, has become notorious for its intensity. Over the last twenty years, Richard Dawkins and Stephen Jay Gould have engaged in a savage battle over evolution that shows no signs of waning. Dawkins, author of The Selfish Gene and The Blind Watchmaker, conceives of evolution as a struggle between gene lineages; Gould, who wrote Wonderful Life and Rocks of Ages, sees it as a struggle between organisms. For Dawkins, the principles of evolutionary biology apply just as well to humans as they do to all living creatures; for Gould, however, this sociobiology is not just ill-motivated but wrong, and dangerous. Dawkins' views have been caricatured, and the man painted as a crazed reductionist, shrinking all the variety and complexity of life down to a struggle for existence between blind and selfish genes. Gould, too, has been falsely represented by creationists as rejecting the fundamental principles of Darwinism itself." "Kim Sterelny moves beyond caricature to expose the real differences between the conceptions of evolution of these two leading scientists. He shows that the conflict extends beyond evolution to their very beliefs in science itself; and, in Gould's case, to domains in which science plays no role at all."--Jacket. Includes bibliographical references (pages 141-151) Battle joined: Clash of perspectives -- Dawkins' world: Genes and gene lineages -- Gene selection in a world of organisms -- Extended phenotypes and outlaws -- Selfishness and selection -- Selection and adaptation -- View from Harvard: Local process, global change? -- Punctuated equilibrium -- Mass extinction -- Life in the Cambrian -- Evolutionary escalator -- State of play: Candle in the dark? -- Stumps summary -- Suggested reading -- Glossary -- Appendix: Geological time scale. Dawkins vs. Gould : survival of the fittest. "Science has seen its fair share of punch-ups over the years, but one debate, in the field of biology, has become notorious for its intensity. Over the last twenty years, Richard Dawkins and Stephen Jay Gould have engaged in a savage battle over evolution that shows no signs of waning. Dawkins, author of The Selfish Gene and The Blind Watchmaker, conceives of evolution as a struggle between gene lineages; Gould, who wrote Wonderful Life and Rocks of Ages, sees it as a struggle between organisms. For Dawkins, the principles of evolutionary biology apply just as well to humans as they do to all living creatures; for Gould, however, this sociobiology is not just ill-motivated but wrong, and dangerous. Dawkins' views have been caricatured, and the man painted as a crazed reductionist, shrinking all the variety and complexity of life down to a struggle for existence between blind and selfish genes. Gould, too, has been falsely represented by creationists as rejecting the fundamental principles of Darwinism itself." "Kim Sterelny moves beyond caricature to expose the real differences between the conceptions of evolution of these two leading scientists. He shows that the conflict extends beyond evolution to their very beliefs in science itself; and, in Gould's case, to domains in which science plays no role at all."--Jacket. Includes bibliographical references (pages 141-151) Battle joined: Clash of perspectives -- Dawkins' world: Genes and gene lineages -- Gene selection in a world of organisms -- Extended phenotypes and outlaws -- Selfishness and selection -- Selection and adaptation -- View from Harvard: Local process, global change? -- Punctuated equilibrium -- Mass extinction -- Life in the Cambrian -- Evolutionary escalator -- State of play: Candle in the dark? -- Stumps summary -- Suggested reading -- Glossary -- Appendix: Geological time scale.