Darwin's Ghost: The Origin of Species Updated Paperback - 2001

First line

Man has a strange relationship with his domestic animals.

Excerpt

ON THE ORIGIN OF SPECIES
INTRODUCTION

According to a 1991 opinion poll, a hundred million Americans believe that "God created man pretty much in his present form at one time during the last ten thousand years." A large majority saw no reason to oppose the teaching of creationism in schools. They followed in a long tradition. A text of 1923, Hell and the High Schools, claimed that "The Germans who poisoned the wells and springs of northern France and Belgium and fed little children poisoned candy were angels compared to the text-book writers and publishers who are poisoning the books used in our schools ... Next to the fall of Adam and Eve, Evolution and the teaching of Evolution in tax-supported schools is the greatest curse that ever fell upon this earth."

Fifty pieces of legislation tried to put a stop to the subject. All failed. Undeterred, Alabama called for a note to be pasted into textbooks: "This book may discuss evolution, a controversial theory some scientists give as a scientific explanation for the origin of living things, such as plants, animals and humans ... No one was present when life first appeared on earth. Therefore, any statement about life's origins should be considered as theory, not fact." In 1999 the Kansas Board of Education voted to remove Evolution from the school curriculum and no doubt other states will try similar tricks.

Such intolerance is new. At the end of the last century few clerics opposed the idea of evolution. In spite of polemic against a "genealogical table which begins in the mud, has a monkey in the middle and an infidel at the tail" most were ready to accept a compromise between The Origin and the Bible. A Day of Creation might be millions of years long, or might represent six real days that marked the origin of a spiritual Man after the long ages it took all else to evolve. Real bigotry had to wait for modern times.

The creationist movement is part of a triumphal New Ignorance that rules in many places, the United States more than most. In fact, the majority of those determined to tell lies to children believe in Darwin's theory and understand how it works-without noticing. Evolution is embedded in the American consciousness for a simple and terrible reason. For the past two decades the nation has lived through an episode that has, with extraordinary speed, laid bare the argument of The Origin of Species. The organism involved was unknown in the nineteenth century, but is now familiar. It is the AIDS virus.

Creationists find it easy to accept the science of AIDS. Its arrival so close to the millennium and the Last Judgment is a useful illustration of God's wrath. Homosexuals, they claim, have declared war on nature, and nature has exacted an awful retribution. Fundamentalists admit the evolution of a virus as nature's revenge but will not concede that the same process acts upon life as a whole.

Even to anti-evolutionists, AIDS is proof of descent with modification because they can see it happening. Its agent has changed in its brief history and has adapted to overcome the many challenges with which it is faced. As death approaches, a patient may be the home of creatures-descendants of those that infected him-as different as are humans and apes. Every continent, with its own sexual habits, has its own exquisitely adjusted set of viruses; and AIDS has relatives in animals quite different from ourselves. Darwin would have been delighted to see the workings of his machine so starkly exposed.

Science makes patterns from ideas. If AIDS can evolve, so can anything else. The Origin uses freshwater bears and flying fish to make a case that applies to all forms of life. For its opponents, in contrast, what is true for viruses cannot be true of birds or fish, let alone a man. The existence of an animal as unlikely as a whale is, for them, proof that evolution does not work.

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.

It was greeted with hysteria. Some claimed that the virus had been placed in Tutankhamen's tomb to punish those who defiled his grave and had come to America with an exhibition of his treasures. An analyst studied what he called its psycho-incubation. AIDS victims, he said, had suffered an emotional emergency in childhood that made them feel abandoned and later led to illness. The editor of Burke's Peeragewent further. To preserve the purity of the human race his publication would not list any family in which a member was known to have the disease: "We are worried that AIDS may not be a simple infection, even if conveyed in an unusual way, but an indication of a genetic defect."

Although some dissenters tried to associate its symptoms with the use of capsules of amyl nitrate to enhance erotic pleasure, the real cause was soon found. The culprit is a virus, the human immunodeficiency virus, or HIV.

Like a whale, the virus is built on an inherited plan coded by genes, each one liable to accident every time it is copied. HIV is unusual even among viruses. As a retrovirus, its genes are based not on DNA, but on its relative RNA (a molecule used in most creatures to translate, rather than to transmit, the genetic message). All retroviruses-and they come in many forms-contain about ten thousand RNA units, or "bases." The AIDS virus subverts its host's cells. It forces them to make replicas of itself with an enzyme whose job is to copy information from the invader's RNA into human DNA. Each new particle hides itself in a cloak of cell membrane into which it inserts a protein. This is the key to the infection as it fits into matched molecules on the surface of blood cells and opens the door to their interior.

The lock that turns to an enemy's key is most abundant on certain cells of the immune system. These multiply in response to infection, but cannot cope with the challenge. Billions of new particles are made each day, and although most are at once destroyed, they soon prevail. Soon after the virus arrives, the number of protective cells falls, only to rise as the body's fight back begins. Then, the immune system begins to collapse. The first sign of illness is a malaise no worse than influenza. This clears up, but HIV stays at work. As the defenders are driven back, other diseases gain a hold. For most people, the transition from infection to overt illness takes from six to ten years.

As AIDS advances there may be pneumonia, fungal infections, diarrhea, weight loss and a viral form of blindness. A cancer called Kaposi's sarcoma, otherwise found among aged Jewish men, quite often appears. Its first sign is purple marks on the skin, but as it progresses it kills. Kaposi's sarcoma is caused by a herpes-like virus common in the homosexual community. It gains entry—because the body's defenses have been undermined. If the patient does not first surrender to a fungus, bacterium or cancer, he wastes away.

The history of AIDS, over days, years and centuries, is simple. It involves descent, accompanied by modification. Each virus divides once a day. Mutation is followed by natural selection that allows the invader to adapt to the body's defenses, to the drugs used to treat it and to the sexual habits of the society in which it lives. Some changes are, it seems, unheeded by selection and build up at random as the generations pass. In time (and it does not take long) new forms of virus emerge.

The genes tell the story. They link a patient with the person who infected him, with others long dead, and with the viruses of apes, cats and whales. Except in its details, and the trivial matter of size, the evolution of the AIDS virus is that of every other being.

Media reviews

"There are few better or more entertaining accounts of the evolutionary process in print today than Darwin's Ghost." - The New York Times


"Steve Jones has now rewritten the original masterpiece, and revitalized it with much evidence that was hidden from Darwin." - The Globe and Mail