BOOK I REVI EW

Needless to say, I strongly recom­ professional mathematician there are sev­ mend that all students of mathematics read eral historical facts and anecdotes, which this book. For the lay person, this is an would enrich his teaching enormously. excellent exposure to mathematics. For One looks forward to Dunham writing the undergraduate student this book serves another book taking on mathematics from as an introduction to many beautiful re­ this century and explaining it to a novice. sults in mathematics and also an opportu­ Dunham has definitely managed to con­ nity to learn about the rich history and vey Sonya Kovalevskaya's feeling that human drama behind these facts. For the mathematics "... is a science which de­ mands the greatest imagination." 2 See R Sridharan's review of the book The Crest of the Peacock, Non-European roots of mathematics Shashidhar J agadeeshan, Centre for Leaming, 462, by George Gheverghese Joseph in the June 1996 9th Cross, Jayanagar, 1st Block, Bangalore 560011 issue of Resonance. E-mail address:[email protected]

River Out of Edenl gested that an organism existed only be­ cause genes had to make more genes. Or­ Darwin Goes Digital: Old View, New ganisms were mere carriers of genes from Metaphor one generation to another. The logic was simple - all bodies die, all genes don't. JA Santosh Genes would survive and march the pas­ sage of geological time if they were good at building bodies capable of reproducing to 1<11 '('1' Ollt 0/ r eiI'll River out of Eden: A Darwinian Wew oflife leave more copies of those genes that would Richard Dawkins make more bodies to make more genes, ... IPhoenix, Orion Books, London, 1995. ad infinitum. The concept progressed p.196, UK £5.99 further in the sequel, The Extended Phenotype, which proposed that genes do Two decades ago, Richard Dawkins un­ not just manipulate bodies, but extend their leashed The Selfish Gene, an intensely com­ control over the world around them shap­ pelling book that reduced organisms to in­ ing it to meet their own reproductive end. significant puppets animated by primeval It was only incidental that the replicating strings of selfish genes. Just as Samuel molecules were packaged for transporta­ Butler observed that a chicken was an egg's tion through time in multicellular throw­ way of making another egg, Dawkins sug- away wrappings called organisms!

1 Note that the author of this book was erroneously mentioned as Stephen Jay Gould on p.77 of the January 1977 issue of Resonance. Editor

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Dawkins, arguably the most forceful nothing new to say, the book's central meta­ popular writer of neo-Darwinism, ex­ phor of the river is appealing in its simplic­ pounds his views with eager passion and ity and lucid in purpose. Introducing the unassailable logic. With the possible ex­ analogy in the first chapter, The Digital River, ception of the more rhetorical Stephen Jay from which the book borrows its title, Gould, he has done more than anyone to Dawkins begins, "There is a river out ofEden, popularize the field of evolutionary biol­ and it flows through time, not space. It is a ogy. With its emphatic advocacy and clear river of DNA .... " The analogy of the river to reasoning, River Out of Eden is vintage compare the flow of genetic information in Dawkins. Though, at first glance, the mili­ species through time and through bodies tant vigour of his former works appears a serves well, on most counts. All individuals little toned down, the severity with which of a species have the same river flowing rival theories and ideas are admonished through them and new species come in to might suggest otherwise. existence when the river forks into two branches (caused by, say, geographical If you have not read Dawkins yet, this isolation of a population). Initially, the is a good book to start with before you move branches may remain close to each other al­ on to his meatier works. The book is smaller lowing waters to mix (inter-breeding be­ than any of its predecessors and is less tween individuals of the two populations), technical. It stands, without doubt, at the but if the rivers diverge further they may get popular extreme of the spectrum of all his too far to mingle (reproductive isolation). writings. Devoid of jargon, the language is Some branches may dry up on the sands of simple but yet maintains the emphasis and extinction. Dawkins discusses the difference persuasion so typical of Dawkins. Further, between analog and digital systems in their the book assumes no advanced knowledge fidelities of information transfer, and main­ of biology, and examples abound to drive tains that Darwinism can be sustained only home the concepts. Those already familiar by a genetic system that is digital. with Dawkins' concepts, will find this a nos­ talgic reinforcement of the gene's-eye view The second chapter, All Africa and of life with varied and new substantiation. Her Progenies, details the logic of the exist­ This book certainly has the potential to ence of Mitochondrial Eve. For those, like accommodate a wide readership ranging me, more familiar with that phrase than the from the curious layman, through the nov­ concept, this is an excellent place to under­ ice biology-student, to die-hard evolution­ stand the deduction. Using the example of ary biologists. the rate of change in the nucleotide sequence of the protein cytochrome c, calculation of Although Dawkins has conceptually evolutionary distances between species is ______,AAAAAA ______

RESONANCE I November 1997 v V VV V v 105 BOOK I REVIEW discussed with such simplicity, that the ra­ of water (tributaries) often do not branch tionale of using molecular clocks becomes away from a river; they start off by them­ glaringly obvious. Do Good by Stealth, the selves, get bigger beforejoining a main river third chapter, is partially an attack on cre­ which might join a bigger river. The River ationism (no book by Dawkins is complete Out of Eden flows in the reverse direction! otherwise). Creationists commonly attack As a metaphor, The Tree of Life, more gradualism in evolutionary theory by argu­ deeply rooted in history, might still stand ing that complex structures, organs or taller. behaviour-patterns that exist in nature could have arisen only instantaneously (cre­ In conclusion, River Out ofEden is a ated), as intermediate half-formed stages simple summary of Dawkins' central propo­ would have been useless. Using examples of sition that genes are the only units that orchids, man, sticklebacks, gulls and tur­ really matter in evolution and that they tran­ keys, Dawkins obliterates that notion and scend the significance of the organism. The points to plausible pathways to the evolu­ book hints at a unifying theory of evolution tion of the eye, bee-dances and wasp-shaped which argues that all of life's grandeur boils orchids. The fourth chapter, God's Utility down to the process of digital-information Function, explains how a gene-centered view transfer. Dawkins at his reductionist best. If shows that nature is neither cruel nor car­ you like work-outs at cerebral gyms, this ing, but only indifferent, to the phenotype. book has weight. The utility function (an economist's term meaning 'that which is maximized') of life Suggested Reading is 'DNA survival'. The last chapter, The Rep­ lication Bomb, talks about the possible ori­ Gould S J. Caring groups and selfish genes. In gin and future of self-replicating molecules. Gould S J. The Panda's Thumb. W W Norton. New Dawkins takes us through the many thresh­ York, 1980. olds that life has passed through during the Gould S J. What happens to bodies if genes act for themselves? In Gould S J. Hen's Teeth and Horses course of evolution, and suggests a possible Toes. W W Norton. New York, 1983. crossing of the next threshold of inhabiting Dawkins R. The Blind Watchmaker. W W Norton. the solar system through space travel. All in New York, 1986. our genes! Dennett D C. DaJ'fA)in's Dangerous Idea. Simon & Schuster. New York, 1995. The river metaphor contains a trivial (Note: Books by W W Norton are available with inconsistency. New branches leave Dawkins' Penguin Books in India.) evolutionary river as it flows through time J A Santosh, Centre for Ecological Sciences, Indian and these may eventually have other Institute of Science, Bangalore S60 012, India. branches leaving them. Many real branches Email:[email protected]

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