Adventures In Evolution Essay Research Paper Adventures

Adventures In Evolution Essay, Research Paper

Adventures in development The Structure of Evolutionary Theory Stephen Jay Gould 1,464 pages, Harvard I Have Landed: Splashs and Contemplations in Natural History Stephen Jay Gould 401pp, Cape There are many grounds to repent the decease of Stephen Jay Gould ; one of the weightiest is that he ne’er had clip to complete his last book at its proper length. Even close to decease, he had twice the energy, scope, and aspiration of most authors ; and the consequence is a last testament which is approximately twice every bit long as it should hold been. At 1,400 pages, and weighing instead more than twice every bit much as the laptop on which I & # 8217 ; m composing this, The Structure of Evolutionary Theory is evidently a book that has excessively many words. But you have to delve into it to detect the existent disadvantage, which is that most of the words have far excessively many syllables. This International Relations and Security Network & # 8217 ; t because they are proficient. Some of the transitions here deal with issues of existent proficient complexness and philosophical trouble, and those are laudably clear. It is in the more general subdivisions that the Latinate orotundities settle in great snowdrifts around the statement, so that the fighting reader is overwhelmed by a warm yearning to lie down and remainder and ne’er rise once more. Yet struggle through the snowdrifts, strengthen yourself with brandy if you must, and you will be rewarded. For the expansive design of the book is impressive, and its aspirations worthwhile and stopping point to accomplishment. What Gould has set out to compose is an history of the development of evolutionary theory ; to look at all the truly interesting inquiries that have arisen since the Origin of Species and to settle the inquiry of how much of the modern scientific discipline that bears his name Darwin would recognize today. So there are chapters on the early options to Darwinism: subdivisions on the outgrowth of modern ( anti-Gouldian ) orthodoxy within evolutionary theory ; one book within a book on the bounds of version ; and another on Gould & # 8217 ; s foremost big theory, punctuated equilibrium. It is all a huge apology, without, of class, any intimation of apology. For the last 20 or 30 old ages, Gould has stood for & # 8220 ; pluralism & # 8221 ; , which, to his oppositions, means woolly-mindedness. In The Structure of Evolutionary Theory, he explains what he truly means. There is no opportunity, in a reappraisal of this length, of covering all his topics, but it is possible to give a spirit of his statement. For a start, and non-controversially, there is the thought that a great trade of the natural stuff of evolutionary alteration is supplied by accident. Natural choice can plan the chiropteran & # 8217 ; s system of echo sounding, but it hasn & # 8217 ; t yet produced a device for guarding off mass extinctions. There is no uncertainty that natural choice makes a great interior decorator, but there is sensible statement about how much of the universe we see is the merchandise of design. Gould has ever argued that his east northeast mies, and most of his co-workers, see excessively much design and excessively many versions in the universe, and coopted from architecture the term & # 8220 ; spandrel & # 8221 ; to depict an undesigned characteristic which is a necessary effect of one that is designed, but is so used as a base for farther design. The difference is possibly one between historiographers and applied scientists: Gould is a palaeontologist every bit good as a historiographer of thoughts. In both contexts, he is interested in development as an history of what really happened. His oppositions, one of whom, John Maynard Smith, really trained as an applied scientist, are much more interested in Darwinism as a timeless mechanism or set of mechanisms. Most of the life scientists I know spent their childhoods constructing things & # 8211 ; it barely mattered what, so long as the spots fitted together in a gratifyingly logical manner. One professor of biological science, when asked to be more precise, replied & # 8220 ; bombs, projectiles, wirelesss & # 8221 ; . But Gould spent his childhood reading books and dreaming of dinosaurs. No admiration he became the scientist for the remainder of us. Gould & # 8217 ; s essays from Natural History magazine & # 8211 ; of which the handsomely produced I Have Landed is the tenth and concluding volume & # 8211 ; are nonpareil illustrations of the strengths of a historical imaginativeness rolling across a scientific topic. They are besides better trimmed than the long book, with far less fat around the meat of the statement, partially because most of the serious statements in his essays are ventriloquised through other people. Gould resembled Isaiah Berlin, in Thursday

at 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 better than others in the eyes of natural selection, and this meaning, these advantages, must almost always appear in bodies. These might not be the body that the gene itself is found in – the plant genes that control the colours of flowers, and make them attractive to bees, are really selected because of the way that bees’ eyes work. That was the argument of Richard Dawkins’s second, technical book, The Extended Phenotype. This seems to prove that you can reduce almost everything about evolution to genes. However, as Gould points out, gene-centrism reached a kind of reductio ad absurdum with the the discovery of “selfish” or “junk” DNA. This is the name given to bits of chromosomes, possibly proper genes, which are copied by the exuberance of the cell’s own copying mechanisms for no reason at all so far as the organism is concerned. These are genes which really are directly selected for their own physical qualities, not for their effects on the physical qualities of the cells that surround them. Their existence shows that normal DNA is selected in a more complicated way. The point at issue is really a confusion between copying and winnowing: selection is a two-stage process, endlessly repeated. Things are copied, then their copies are winnowed to select ones with certain qualities, and the survivors are copied again. But in genetic systems, copying and winnowing are separate process (except in the specialised case of junk or selfish DNA): the things that are copied – the genes – are not the things that are winnowed – the bodies. Neither the copying nor the winnowing can sensibly be called “selection” on its own. Nonetheless, it makes sense to ask what sorts of things are winnowed, and here Gould does go out on a limb. He argues that not merely individual bodies, but populations, whole species, and even clades – related groups of species – can compete with each other in a Darwinian sense, and so become the objects of selection. This idea brings together two of his constant themes, for he argues that adaptation at one level of the hierarchy is what produces the spandrels at the next level that provide the raw material for further adaptation in their turn. That would explain, for example, how the duplication of genes when they are copied into junk DNA, which is a product of purely molecular selection, nonetheless supplies the raw material or spandrels for natural selection to work on the organism. It is not at all clear how much this would revolutionise biology, nor how Gould might reconcile this kind of multi-level selectionism with his other belief that much evolutionary change is essentially random. It was a consistent complaint of Gould’s opponents that he oversold his own ideas. But he did have an enormous amount to oversell, and it is saddening to reflect that he will never now write more, or less.