Читать реферат по английскому: "Adventures In Evolution Essay Research Paper Adventures" Страница 1

(Назад) (Cкачать работу)

Adventures In Evolution Essay, Research Paper

Adventures in evolution The Structure of Evolutionary Theory Stephen Jay Gould 1,464 pages, Harvard I Have Landed: Splashes and Reflections in Natural History Stephen Jay Gould 401pp, Cape There are many reasons to regret the death of Stephen Jay Gould; one of the weightiest is that he never had time to finish his last book at its proper length. Even close to death, he had twice the energy, range, and ambition of most writers; and the result is a last testament which is about twice as long as it should have been. At 1,400 pages, and weighing rather more than twice as much as the laptop on which I’m writing this, The Structure of Evolutionary Theory is obviously a book that has too many words. But you have to dig into it to discover the real disadvantage, which is that most of the words have far too many syllables. This isn’t because they are technical. Some of the passages here deal with issues of real technical complexity and philosophical difficulty, and those are admirably clear. It is in the more general sections that the Latinate orotundities settle in great snowdrifts around the argument, so that the struggling reader is overwhelmed by a warm longing to lie down and rest and never rise again. Yet struggle through the snowdrifts, fortify yourself with brandy if you must, and you will be rewarded. For the grand design of the book is impressive, and its ambitions worthwhile and close to achievement. What Gould has set out to write is an account of the evolution of evolutionary theory; to look at all the really interesting questions that have arisen since the Origin of Species and to settle the question of how much of the modern science that bears his name Darwin would recognise today. So there are chapters on the early alternatives to Darwinism: sections on the emergence of modern (anti-Gouldian) orthodoxy within evolutionary theory; one book within a book on the limits of adaptation; and another on Gould’s first large theory, punctuated equilibrium. It is all a vast apologia, without, of course, any hint of apology. For the last 20 or 30 years, Gould has stood for “pluralism”, which, to his opponents, means woolly-mindedness. In The Structure of Evolutionary Theory , he explains what he really means. There is no chance, in a review of this length, of covering all his subjects, but it is possible to give a flavour of his argument. For a start, and non-controversially, there is the idea that a great deal of the raw material of evolutionary change is supplied by accident. Natural selection can design the bat’s system of echolocation, but it hasn’t yet produced a device for warding off mass extinctions. There is no doubt that natural selection makes a great designer, but there is reasonable argument about how much of the world we see is the product of design. Gould has always argued that his ene mies, and most of his colleagues, see too much design and too many adaptations in the world, and coopted from architecture the term “spandrel” to describe an undesigned feature which is a necessary consequence of one that is designed, but is then used as a base for further design. The dispute is perhaps one between historians and engineers: Gould is a paleontologist as well as a historian of ideas. In both contexts, he is interested in evolution as an account of what actually happened. His opponents, one of whom, John Maynard Smith, actually trained as an engineer, are much more interested in Darwinism as a timeless mechanism or set of mechanisms. Most of the biologists I know spent their childhoods building things – it hardly mattered what, so long as the bits fitted together in a satisfyingly logical way. One professor of biology, when asked to be more precise, replied “bombs, rockets, radios”. But Gould spent his childhood reading books and dreaming of dinosaurs. No wonder he became the scientist for the rest of us. Gould’s essays from Natural History magazine – of which the handsomely produced I Have Landed is the 10th and final volume – are matchless examples of the strengths of a historical imagination roaming across a scientific subject. They are also better trimmed than the long book, with far less fat around the meat of the argument, partly because most of the serious arguments in his essays are ventriloquised through other people. Gould resembled Isaiah Berlin, in that he could most successfully expound his own ideas when they were presented as coming from others. The historical sections of The Structure of Evolutionary Theory are packed full of evolutionary theory presented in the clearest and most comprehensible way. The avowedly theoretical sections are much more tangly, though the ideas he is presenting are not in themselves more difficult. Nonetheless, he did manage to knot together in the final sections several of his lifelong themes in a very comprehensible way, among them his objection to “gene-centric” ideas of evolution. To the engineering mind, the wonderful thing about genes, ever since their chemical nature was unravelled by Watson and Crick, is that this nature turned out to be digital. DNA, like light and matter, comes in chunks that are precise and measurable. Just as the physicists were getting all woolly and mystical, the biologists got themselves a really hard science. The differences of style harden into greater substance when you ask what the entities are on which natural selection can operate. Are they genes, or bodies, or even whole species? For Darwin, working 50 years before the word “gene” was even coined, they were organisms – individual bodies. Individual giraffes had more descendants because they had longer necks. Once genetic inheritance was discovered, it seemed obvious that genes were the only thing that natural selection could act on. But this, while fascinating, has to be partly wrong. The meanings of a gene are the things about it that make some versions

Похожие работы