Darwin, Ahead of His Time, Is Still Influential By NICHOLAS WADE The New York Times February 10, 2009
Darwin's theory of evolution has become the bedrock of modern biology. But for most of the theory's existence since 1859, even biologists have ignored or vigorously opposed it, in whole or in part. It is a testament to Darwin's extraordinary insight that it took almost a century for biologists to understand the essential correctness of his views. Biologists quickly accepted the idea of evolution, but for decades they rejected natural selection, the mechanism Darwin proposed for the evolutionary process. Until the mid-20th century they largely ignored sexual selection, a special aspect of natural selection that Darwin proposed to account for male ornaments like the peacock's tail. And biologists are still arguing about group-level selection, the idea that natural selection can operate at the level of groups as well as on individuals. Darwin proposed group selection - or something like it; scholars differ as to what he meant - to account for castes in ant societies and morality in people. How did Darwin come to be so in advance of his time? Why were biologists so slow to understand that Darwin had provided the correct answer on so many central issues? Historians of science have noted several distinctive features of Darwin's approach to science that, besides genius, help account for his insights. They also point to several nonscientific criteria that stood as mental blocks in the way of biologists' accepting Darwin's ideas. One of Darwin's advantages was that he did not have to write grant proposals or publish 15 articles a year. He thought deeply about every detail of his theory for more than 20 years before publishing "On the Origin of Species" in 1859, and for 12 years more before its sequel, "The Descent of Man," which explored how his theory applied to people. He brought several intellectual virtues to the task at hand. Instead of brushing off objections to his theory, he thought about them obsessively until he had found a solution. Showy male ornaments, like the peacock's tail, appeared hard to explain by natural selection because they seemed more of a handicap than an aid to survival. "The sight of a feather in a peacock's tail, whenever I gaze at it, makes me sick," Darwin wrote. But from worrying about this problem, he developed the idea of sexual selection, that females chose males with the best ornaments, and hence elegant peacocks have the most offspring. Darwin also had the intellectual toughness to stick with the deeply discomfiting consequences of his theory, that natural selection has no goal or purpose. Alfred Wallace, who independently thought of natural selection, later lost faith in the power of the idea and turned to spiritualism to explain the human mind. "Darwin had the courage to face the implications of what he had done, but poor Wallace couldn't bear it," says William Provine, a historian at Cornell University. (Read commentary by Dr. Provine on passages from "On the Origin of Species." ) Darwin's thinking about evolution was not only deep, but also very broad. He was interested in fossils, animal breeding, geographical distribution, anatomy and plants. "That very comprehensive view allowed him to see things that others perhaps didn't," says Robert J. Richards, a historian at the University of Chicago. "He was so sure of his central ideas - the transmutation of species and natural selection - that he had to find a way to make it all work together." (Dr. Richards comments on "On the Origin of Species.") ... http://www.nytimes.com/2009/02/10/science/10evolution.html *********************************** * POST TO [email protected] * *********************************** Medianews mailing list [email protected] http://lists.etskywarn.net/mailman/listinfo/medianews
