26 de enero de 2009

Darwin, Charles Robert

Darwin, Charles Robert
Charles Robert Darwin, the British biologist whose theory of organic evolution revolutionized science, philosophy, and theology, was born at Shrewsbury. He atended the universities of Edinburgh and Cambridge but was not attracted by his medical studies at the first or by his theological studies at the second. Near the end of his undergraduate days he formed a friendship with J. T. Henslow, professor of botany at Cambridge, “a man who knew every branch of science” (Autobiography of Charles Darwin).
This association, together with an enthusiasm for collecting beetles and a reading of works by Wilhelm von Humboldt and John Herschel, generated in him “a burning zeal to contribute to the noble structure of Natural Science.” The opportunity to do so on a large scale arose when Henslow secured for him the post of naturalist “without pay” aboard the H.M.S. Beagle, then about to begin a long voyage in the Southern Hemisphere. Thus, between 1831 and 1836 Darwin was able to make extensive observations of the flora, fauna, and geological formations at widely separated points on the globe. This experience determined the course of his life thereafter and laid the foundation for many of his fundamental ideas. On his return he lived in London for six years, where he became acquainted with leading scientists of the day. Sir Charles Lyell, Sir Joseph Hooker, and T. H. Huxley were among his most intimate friends. In 1842 he took up residence at Down, a secluded village in Kent.
Here, during the forty years until his death, he conducted the researches and wrote the works that made him famous. He was buried in Westminster Abbey close to the grave of Sir Isaac Newton.
Darwin’s productivity, despite recurrent bouts of illness, was prodigious. His publications ranged over such diverse subjects as volcanic islands, coral reefs, barnacles, plant movement, the fertilization of orchids, the action of earthworms on the soil, the variation of domesticated animals and plants, and the theory of evolution. Even if he had never written The Origin of Species (1859) and The Descent of Man (1871), he would still be regarded as one of the great biologists of the nineteenth century. Of course, it was these two books that made him the initiator of a revolution in thought more far-reaching than that ushered in by Nicolas Copernicus. He established beyond reasonable doubt that all living things, including man, have developed from a few extremely simple forms, perhaps
from one form, by a gradual process of descent with modification. Furthermore, he formulated a theory (natural selection), supporting it with a large body of evidence, to account for this process and particularly to explain the “transmutation of Species” and the origin of adaptations. As a result, the biological sciences were given a set of unifying principles, and man was given a new and challenging conception of his place in nature.
It was characteristic of Darwin that he came to these conclusions by his own observations and reflections.
When he embarked on the Beagle, his outlook was “quite orthodox.” He accepted without question the fixity of species and their special creation as depicted in Genesis.
Doubts began to arise in his mind during the ship’s visit to the Galápagos Archipelago in 1835, when he noticed that very small differences were present in the so-called species inhabiting separate islands. The doubts were reinforced by his observation of fossils on the Pampas and the distribution of organisms on the South American continent as a whole. He was “haunted” by the idea that such facts “could be explained on the supposition that species gradually became modified.” In July 1837 he “opened his first notebook” to record additional facts bearing on the question, but it was not until he happened to read Thomas Robert Malthus’s Essay on Population in October 1838 that he found an explanatory theory from which the above “supposition” followed. He then proceeded to formúlate the principle of natural selection, which is simply “the doctrine of Malthus applied with manifold force to the whole animal and vegetable kingdoms.”Darwin never professed to have invented the idea of organic evolution, of the mutability of species, or even of natural selection.
What he did profess was to have produced the first scientific proof that these ideas apply to the living world.
Unlike some lesser men of science, Darwin was not inclined to rush into print in order to establish a proprietary right to his theory. His modesty and single-minded desire to find out the truth forbade any such action.
Accordingly, the theory underwent several preliminary formulations. It was first set down in a short abstract in 1842 and two years later was expanded into an essay that both Lyell and Hooker read. Early in 1856 Lyell advised Darwin to write a full-length account of his views. It was when this manuscript, which would have been “three or four times as extensive” as The Origin of Species, was about half finished that Alfred Russel Wallace’s paper, which contained virtually the same ideas that Darwin was working out, arrived at Down from the Malay Archipelago.
The resulting crisis was resolved by having a joint communication from the two men read at a meeting of the Linnaean Society on July 1, 1858. Between September of that year and November 1859, Darwin “abstracted” the large manuscript and produced his classic. The Origin of Species appeared on November 24 in an edition of 1,250 copies, all of which were sold on the first day. Ultimately, six editions containing many revisions were published.
Despite the interest that The Origin of Species excited, it was by no means universally approved at first. In the scientific world support for it came from Darwin’s friends, but others expressed opposition that often took the form of objections to the modes of explanation and proof employed in the work. Darwin’s use of historical or genetic explanations, his implicit adoption of statistical conceptions (“population thinking,” as it is now called), and his practice of introducing conjectures or “imaginary illustrations” to buttress his argument were repugnant to biologists who held that scientific explanation must consist in bringing directly observed phenomena under general laws. Believers in this oversimplified model also disliked his notion of “chance” variations and his repudiation of “any law of necessary development.” Before long, however, the cumulative force of Darwin’s arguments, augmented by the case put forward in The Descent of Man, convinced the great majority of biologists, so that opposition from this quarter had disappeared by 1880.
The popular reaction to Darwin’s theory focused on its religious and ideological implications. These were recognized to be hostile to the Establishment. Hence, Darwin found himself enthusiastically supported by radicals, rationalists, and anticlericals and vehemently attacked by reactionaries, fundamentalists, and priests. He shrank from entering into this controversy, which was altogether distasteful to him, but T. H.Huxley, who enjoyed crossing swords with theologians, took a different stand. Appointing himself “Darwin’s bulldog,” he relentlessly pursued such antievolutionists as Bishop Wilberforce and W. E.
Gladstone.His efforts had a good deal to do with creating the image of Darwin as an enemy of the Bible, the church, and Christianity.
This image was, in fact, fairly close to the truth. Darwin’s religious beliefs, as he relates in his Autobiography, underwent a change from naive acceptance of Christian doctrines to reluctant agnosticism. In the two years following his return from the voyage of the Beagle he was “led to think much about religion.” Doubts were engendered in his mind about the historical veracity of the Gospels, the occurrence of miracles, and the dogma of everlasting damnation of unbelievers (which he calls “a damnable doctrine”). By reflection on such matters he “gradually came to disbelieve in Christianity” and wondered how anybody could wish it to be true.
A similar erosion occurred in connection with his belief in the existence of a personal God.When he wrote The Origin of Species, Darwin accepted a vague theism or deism. In the last chapter he speaks of laws having been “impressed on matter by the Creator” and of life’s powers “having been breathed by the Creator into a few forms or into one.”He was thus able at the time to deny that it was his intention “to write atheistically.”Yet it was also clear to him that the theory of natural selection exploded the old argument for theism based on the presence of design in the organic world. The vast amount of suffering and misery that exists seemed to him a strong argument against any belief in a beneficent First Cause. He had moods in which it seemed difficult or impossible to conceive that “this immense and wonderful universe, with our conscious selves, arose through chance.” In the end, however, he concluded “that the whole subject is beyond the scope of man’s intellect.… The mystery of the beginning of all things is insoluble by us; and I for one must be content to remain an Agnostic.”
Darwin’s reflections on religion, although not systematic, provide a good example of his intelectual integrity. “I have steadily endeavored,” he wrote in his Autobiography, “to keep my mind free, so as to give up any hypothesis, however much beloved (and I cannot resist forming one on every subject), as soon as facts are shown to be opposed to it.” That statement might well serve as his epitaph.