The other view of the origin of whales, men or viruses is simple. As many more individuals of each species are born than can possibly survive and as, consequently, there is a frequently recurring struggle for existence, it follows that any being, if it vary however slightly in any manner profitable to itself, under the complex and sometimes varying conditions of life, will have a better chance of surviving, and thus be naturally selected. From the strong principle of inheritance, any selected variety will tend to propagate its new and modified form.
Every part of Darwin's thesis is open to test. The clues - from fossils, genes or geography - differ in each case, but from all of them comes the conclusion that the whole of life is kin. That is no mere assertion, but a chain of deduction with every link complete. The biography of the AIDS virus, one of Nature's newest and tiniest products, is almost complete and that of whales - the largest animals ever seen - is fragmentary, but they are cousins under the skin. The AIDS virus is change seen under the microscope, and the whale the same process viewed, in glimpses and over long ages, through a biological telescope. Evolution at the extremes of size is an apt prelude to the great drama that is Darwinism.
Creationists often deny the possibility of an intermediate between two species. Take whales and land animals. What use are flippers on solid ground, or feet in the sea? "There are simply no transitional forms in the fossil record between the marine mammals and their supposed land mammal ancestors ... It is quite entertaining to attempt to visualize what the intermediates may have looked like. Starting with a cow, one could even imagine one line of descent which prematurely became extinct, due to what might be called an udder failure." The complaint (and the leaden humor) is not new. A London newspaper of 1859 said of Darwin's "whale" passage that "With such a range and plasticity ... we know not where to stop - centaurs, dryads and hamadryads and (perhaps) mermaids once filled our seas."
Nobody has ever seen a mermaid, or even a dinosaur. Evolution is, most of the time, an attempt to reconstruct a history whose pace is far slower than that of those who study it. AIDS is unique because genes and time come together on a human scale. Darwin himself saw disease as a model of change. Almost the first recorded hint of his theory is in a note made on the Beagle. He was told by the surgeon on a whaling ship that lice from Sandwich Islanders will not survive on Europeans. How, he asked, could this be - unless each had diverged from the same ancestor? Why should a Creator, if parasites were needed, not make a universal louse for all mankind?.
AIDS came to notice in 1981 with a report of a sudden increase in a certain form of pneumonia. As the sober language of the Morbidity and Mortality Weekly Report of the United States Centers for Disease Control put it: "The fact that these patients were all homosexuals suggests an association between some aspect of homosexual life-style or disease acquired through sexual contact and Pneumocystis pneumonia in this population." The illness became notorious with the death of the actor Rock Hudson in 1985. By then, more than twelve thousand Americans were dead or dying. Within a decade, half a million had perished. Nobody guessed that such a rare disease would become a pandemic. Camus, in The Plague, has it that: "A pestilence isn't a thing made to man's measure therefore we tell ourselves that pestilence is a mere bogey of the mind, a bad dream that will pass away. But it doesn't always pass away, and from one bad dream to another it is men who pass away." They did and, more and more, they will.
AIDS, like the Great Pox of the fifteenth century, is spread by sex. The ground was well prepared before its seeds were planted. In the 1970s, five thousand gay men moved to San Francisco each year. By 1980, venereal disease was widespread - and four out of every five of the patients were homosexual men. A typical AIDS victim admitted to sex with eleven hundred people in his lifetime, while some claimed as many as twenty thousand partners. Most of the city's homosexual males had the viral illness known as hepatitis B, and many suffered from gay bowel syndrome, multiple gut infections acquired from the curious sexual habits of part of their community. Casual sex in bathhouses - the Cornhole, the Boom Boom Room, the Toilet Bowl - helped the diseases to spread. AIDS, though, was new.
Excerpted from Darwin's Ghost by Steve Jones Copyright© 2000 by Steve Jones. Excerpted by permission of Random House, a division of Random House, Inc. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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