resemblance n. 类似，相似 
　diagnose vt. 1.诊断(疾病) 2.探查（机械故障、问题的）原因 
　prescription n. 1.处方，药方 2.药；治疗方法 
　staircase n. 楼梯 
　synthesis n. 1.综合，合成 2.综合体，综合物 
　immerse vt. 1.使深陷于，使专心于 2.使完全浸没；使淹没 
　genome n. 基因组，染色体组 
　compile vt. 编辑；编纂；汇编 
　atlas n. 1.图表集 2.地图册 
　silicon n. 硅 
　pirate n. 1.剽窃者，侵犯版权者 2.海盗
vt. 剽窃；非法翻印 
　susceptible a. 1.易感染上（疾病）的; 易受（问题）影响的 2.易受影响的 
　notwithstanding prep. 虽然，尽管
ad. 尽管如此; 仍然 
　perfection n. 1.完美，无暇 2.完美的人或事 3.使完美的行为或过程 
　commonplace a. 到处可见的，寻常的
n. 平常的或普通的事 
　interim n. 间歇，过渡期间
a. 过渡期间的，临时的 
　disposition n. 1.倾向 2.秉性，脾气，性情 3.排列，布置 
　ward v. 避免，防止
n. 1.病房 2.选区，（城市的）行政区 
　latent a. 潜伏的；潜在的；不易察觉的 
　cholesterol n. 胆固醇 
　artery n. 1.动脉 2.干线 
　notation n. 1.注释 2.记号, 符号 
　spine n. 脊椎，脊柱 
　sue v. 1.提出诉讼，控告 2.请求，要求 
　heir n. 继承者；继承人 
　resultant a. 作为结果发生的, 因……而产生的 
　preclude vt. 避免，阻止 
　refute vt. 驳斥；反驳 
　plausible a. 1.似乎有道理的，可能的，可以接受的 2.花言巧语的，能说会道的 
　premise n. 1.前提，假定 2.建筑物及其周围所属土地 
　correlate v. 使相互关联；（显示）有相互关系 
Phrases and Expressions

　turn out (to be) 结果是 
　spell out 讲清楚，详细地说明 
　nothing less than 至少，不少于, 不亚于 
　tear apart 拆毁，拆开 
　build up 增多，形成 
　bring on 引起，导致 
　back down 屈服，让步 
　among other things 除别的以外，包括 
　nothing more than 不过，不强于，不多于 
　compatible a. 能够共存的，相容的，协调的 
　transplant vt. 移植（组织或器官）
n. 1.移植（手术） 2.移植的器官，移植物 
　commence v. 开始；起动 
　syndrome n. 综合征；综合症状 
　rein v. 1.抑制，控制 2.用缰绳驾驭马匹
n. 1.缰绳；安全绳套 2.控制手段；控制地位 
　sober a. 1.审慎的；严肃的；冷静的 2.清醒的；未喝醉的 
　veto vt. 否决，禁止；不接受（计划或建议）
n. 否决；禁止 
　minimal a. 最小的；极少的 
　compensate v. 赔偿，补偿
vi. 抵消；弥补 
　adjoining a. 相邻的；毗连的 
　prospective a. 预期的；未来的 
　suppress vt. 1.抑制 2.镇压；制服 
　inhibit vt. 1.抑制；阻止 2.使（某人）拘谨 
　mutation n. 突变 
　complexion n. 1.面色；肤色 2.性质 
　monopoly n. 1.垄断，独占 2.垄断（权），专营（权） 
　custom-designed a. 定制设计的 
　specification n. 规格；规范; 明细表 
　remainder n. 其余（的人）；剩余物 
　elevate vt. 1.增加（数量），提高（温度、压力等） 2.提高，提升 
　drought n. 干旱，旱灾 
　diligent a. 1.细致的，彻底的 2.勤勉的，刻苦的 
　adverse a. 1.不利的，有害的 2.敌对的，相反的 
　parasite n. 寄生物，寄生虫 
　interact vi. 互相作用 
　inventory n. 1.存货，库存量 2.财产目录，清单 
　quantify vt. 确定……的数量，表示……的数量 
　equator n. 赤道 
　duplicate vt. 复写，复制
a. 复制的
n. 复制品；复印件 
　retention n. 1.保持，保留 2.记忆能力 
Phrases and Expressions

　genetic engineering 遗传工程（学） 
　for better or for worse 不管是好是歹，不论是祸是福 
　take stock of 仔细考虑，仔细掂量 
　direct at 以……为目标；瞄准 
　pass on 传给，往下传 
　endow with 赋予，赐予 
　subject to 取决于……的，有待于……的 

A Revolution in Biology — and Society?
      Dissolved in a test tube, the essence of life is a clear liquid. To the naked eye it bears a strong resemblance to water. But when it is stirred, the "water" turns out to be sticky and thick, clinging to a glass rod and forming long, hair-thin threads. "You get the feeling this is really different stuff," says Dr. Francis Collins in his laboratory. Collins heads a gigantic effort to catalog the library of biological data locked in those threads, a challenge he compares with splitting the atom or going to the moon.

      In his laboratory at a university in California, Dr.W.French Anderson looks at the same clear liquid and sees not a library but a drug factory. This scientist's goal, and his passion, is to find the wonder drugs hidden in that test tube. Someday, he says, doctors will simply diagnose their patients' illnesses, give them a prescription for the proper pieces of molecular thread, and send them home cured.

      This thread of life, of course, is DNA, the spiral- staircase -shaped molecule found in the nuclei of cells. Scientists have known since 1952 that DNA is the basic stuff of genetics. They've known its chemical structure since 1953. They know that human DNA acts like a biological computer program that spells out the instructions for the synthesis of proteins, the basic building blocks of life.

      But everything the scientists have accomplished during the past half-century is just a preface to the work in which Collins and a multitude of his colleagues are now immersed. Collins leads the Human Genome Project, a 15-year effort to compile the first detailed atlas of every detail in human DNA. Anderson, who pioneered the first successful human gene-therapy operations, is leading the campaign to put information about DNA to use as quickly as possible in the treatment and prevention of human diseases.

      What they and other researchers are plotting is nothing less than a biological and medical revolution. Like Silicon Valley pirates tearing apart a computer chip to steal a competitor's secrets, genetic engineers are studying life's secrets and trying to use that knowledge to reverse the natural course of disease. DNA in their hands has become a drug, a substance of extraordinary potential that can treat not just symptoms or the diseases that cause them but also the flaws in DNA that make people susceptible to a disease.

      And that's just the beginning. Notwithstanding all the frantic work being done, science is still far away from the creation of human perfection. Much more research is needed before gene therapy becomes commonplace, and many diseases will take decades to conquer, if they can be conquered at all.

      In the interim, the most practical way to use the new technology will be in genetic testing. Doctors will be able to detect all sorts of flaws in DNA long before they can be fixed. In some cases this knowledge may lead to treatments that delay the onset of the disease or soften its effects. Someone with a genetic disposition to heart disease, for example, could ward off a latent heart attack by following a low-fat diet to prevent cholesterol from building up in his arteries. And if scientists determine that a vital protein is missing because the gene that was supposed to make it is faulty, they might be able to give the patient an artificial version of the protein. But in other instances, almost nothing can be done to stop the damage brought on by genetic defects.

      This is the dilemma currently posed by the genetic revolution. Do people want to know about genetic defects that can't be corrected yet? Do they want a notation describing a genetic defect added to their permanent medical records? The danger for many people in whom a genetic disease has been diagnosed is that if they leave their job (and their health insurance), they may never get another. In one case, an insurance company discovered that the baby a client was carrying had the gene for a serious inherited spine disease. The company told her it would pay for an abortion, but that if she chose to have the child, it would not pay for any treatments. The woman had the child, and threatened to sue the company, forcing it to back down.

      "You're going to see things you won't believe," says a professor of health law. He thinks it is only a matter of time before someone sweeps up some of Bill Clinton's hair at the barber shop, runs a genetic scan on the DNA in the hair cells and publishes a list of diseases to which the former President is heir. Under current law, there is nothing Clinton or anyone else could do to stop it. This expert is worried that samples from routine blood tests on ordinary citizens could be screened and that the resultant genetic information might eventually find its way into the vast DNA data banks. To prevent misuse of this information, he has proposed a series of guidelines that would, among other things, preclude genetic data collected for one purpose being used for another.

      There is already talk of a revolt against the notion that we are nothing more than our genes. The editor of the scientific journal Nature warns that the greatest drawback of the genome project may be what he calls the "arrogant optimism" that accompanies a rush of discoveries, leaving the impression that scientists know a lot more than they do. Studies claiming to have found genes for high IQ, for instance, have been refuted by many scientists. Many people, however, still accept as plausible the premise that complex phenomena are determined by our genes.

      Even if there were a gene for, say, criminal activity, what would society do about it? One scientist points out that "we already have a true genetic marker, which can be detected before birth, that is correlated with violence." The individuals with this gene, he says, are nine times as likely to get arrested and convicted for a violent act as people without the gene.

The New Age of Genetic Engineering
      Ready or not, the world is entering the age of genetic engineering. Altered environments and human-created life forms will be part of this new age. Plants may be transformed into miniature factories producing plastics, medicines, or perfumes. Animals may be given human genes to make their tissues compatible with humans, allowing animal hearts and other organs to be transplanted into critically ill people.

      Scientists have cloned animals, and the cloning of humans may soon commence. Gene therapy research is exploring ways to treat various inherited syndromes. The transfer of genes between bacteria, plants, and animals provides opportunities for altering organisms and even creating new ones.

      Many people believe we should rein in the use of genetic knowledge. They realize that they can be identified by their DNA, possibly compromising their personal privacy. In addition, genetic tests that reveal inherited diseases could prejudice employers against them.

      For better or for worse, genetic engineering will affect the major environmental problems of our time: increasing population, pollution, and the rapid loss of biodiversity. It is crucially important that we take stock of this technology's probable effects on our planet's ecosystems.

      We should also take a sober look at the effects of genetic engineering in the social and political realms. Because the agricultural and medical benefits of genetic engineering are expensive, poor individuals and poor nations will not be able to afford them — at least not for years to come. As a result, the economic gap between rich and poor is likely to widen. In addition, Third World leaders have sometimes vetoed the use of their plant and animal species in genetic research. Western companies want these species for genetic engineering projects and hope to obtain them with minimal expense; Third World leaders want to ensure that their people are fairly compensated if these species are used to produce something of value.

      Dangers to the Environment and to Humans

      It's a possibility that could become a nightmare: A genetically engineered crop, say a new type of cucumber, might accidentally reproduce with a wild relative in an adjoining field — a weed. The new weed could inherit the genetically altered crop's ability to poison hungry insects and to withstand big doses of weed-killing chemicals. Insect-proof, hard-to-kill weeds would not be welcome in twenty-first-century agriculture!

      As with the environment, genetic engineering of humans has the potential to be dangerous. Because of the dangers involved, work on gene therapy for humans is proceeding cautiously, but the prospective rewards of gene therapy are tremendous: we may be able to suppress or even prevent inherited disease. At present, gene therapy is being directed at the working cells in a human body that do not pass on genes to the next generation. Therapy someday will be directed at germ cells — sperm and egg cells — that do transmit genetic information to the next generation. Such therapy would remove, replace, alter, or inhibit the genes that cause inherited diseases; however, mistakes in such gene therapy could cause extreme mutations. This is an area of medical research in which work must proceed with great care. No errors can be tolerated.

      When gene therapy has become a precise procedure, prospective parents will be faced with a wide range of possibilities. Of course, they will want to make sure that, at their offspring's embryo stage, gene therapists correct any problems due to faulty genes. Parents also may want the therapists to boost their children's IQ; add inches to their height; or endow them with superior athletic ability, curly hair, blue eyes, and a good complexion. The possibilities for genetic engineering are likely to be vast, but only for millionaire parents. The wealthy would surely have a monopoly on "custom-designed babies" , because creating a baby according to parents' specifications would be far too expensive for the remainder of Americans, or most people in other countries.

      Genetic Diversity Must Be Maintained

      Nature is never idle. Through random mutations, nature constantly tests new genetic models of organisms. Most of the time the mutations are not beneficial and the organism dies. If the environment changes, however, new models that possess appropriate genes for survival will replace the standard models. One veteran wheat breeder tells me "nature does most of the work" when new strains of wheat undergo testing. If a strain under study remains vigorous despite elevated temperatures or drought, or disease problems in adjacent plots, it may be a winner — always subject to further diligent testing.

      Plant breeders recognize the danger of reducing a crop's gene pool and want to maintain the genetic variety the plants may need to meet future adverse conditions. For example, in 1970 a new type of corn parasite swept through corn fields in the United States. At the time, almost all common corn varieties were closely related, and virtually all were susceptible to the new parasite. If the corn varieties had been more genetically diverse, the corn problem might not have become an epidemic.

      In wild areas, a diversity of life forms interact with each other in complex ways to create a healthy ecosystem, but people and other ecological hazards can disrupt this natural biodiversity. Nature's inventory of life forms is decreasing, although the decline can't be exactly quantified. For instance, tropical forests near the equator are the habitat for about half of the Earth's biological species — and each minute of every day 100 acres of this habitat disappears.

      Scientists find valuable genetic material in unlikely places. An unusual bacterium, discovered in a hot spring in Yellowstone National Park, played a vital role in developing a process to synthesize DNA. The bacteria can grow at 86oC, a temperature at which other bacteria are killed. A heat-resistant protein produced by the bacteria made it possible to duplicate DNA molecules in large numbers.

      The retention of genetic diversity everywhere in the world is in our interest; genetic material from a rare bamboo in a remote location might someday provide a crucial therapy. Protecting only a particular species would not be useful: species exist in ecosystems, and their survival depends on ecosystem conservation.

Understanding the Genome Is Only the Beginning
      The race to sequence the human genome has received so much public attention that people forget it's only the first leg of a much longer journey, according to leading scientists.

      The next step is to figure out what all the newly discovered genes actually do, says J. Craig Venter, who announced in June that his company had finished sequencing the human genome. He estimates that 60% of those human genes "are of unknown function. We're still in the very early stages of this science."

      "If determining the gene sequence is a hundred-yard dash, then interpreting it is a cross-country run," says another genetics expert, who worked with Venter to sequence and publish the entire fruit fly genome in 1999.

      To give an idea of the amount of data scientists must sort through and analyze, Venter explains that if the fruit fly genome — all the genetic instructions for making a fly — were printed out on paper, it would take up 27,000 pages, "but the human genome is 20 times larger."

      Digging Deeper, from Genes to Proteins

      To understand the roughly 100,000 genes in the human genome, researchers say they must investigate an even more complicated set of molecules — proteins. Genes are the basic instructions for making proteins, and the "sequence" of a gene — its structure — determines the kind of protein it makes. Some proteins become building blocks for structural parts of the cell. Other proteins become molecular "machines" that carry out the multitude of activities necessary to keep the cell and the body working properly.

      With an understanding of human proteins, scientists will be able to fight diseases on many fronts. For example, scientists in Denmark have isolated a protein that may fight diabetes (糖尿病). Diabetes seems to be caused when crucial cells are accidentally killed by the body's immune system. The scientists spent years analyzing the proteins present in diabetes-prone and diabetes-resistant cells, and they tentatively concluded that the newly discovered protein protects diabetes-prone cells from being attacked by the immune system. Preliminary animal tests, in which the gene for this protein has been inserted into diabetes-prone cells, seem to confirm this hypothesis.

      Effective cancer drugs may also arise from a deeper understanding of genes and proteins, says Ken Croplin, president of one of the many companies working to devise new drugs based on genetic knowledge. Soon, scientists will be able to quickly and accurately compare cancer tissue with normal tissue to see which genes are "switched on" and making proteins (expressed) and which genes are not, he says.

      "If you found a gene that was highly expressed in lung cancer cells but not other tissues, you could guess that that gene was involved in lung cancer," according to Croplin. "We would then try to develop in the lab a way to block the expression of that gene." One possibility would be a "small molecule" drug that would attach to the gene and shut it off, preventing that gene's protein from being produced.

      Finally, drugs themselves will likely become safer and more effective because they will be tailored to an individual's genetic ability to process medicines, predicts another expert. In the future, a blood test could show how much of a particular drug-processing protein a person has, which would be a measurement of that person's ability to process a certain medicine. The doctor would then adjust the dose accordingly or prescribe a drug that is custom-designed for that person's genetic structure. This new technique should eliminate many of the drug side effects that result from our current, crude methods of determining the correct dose for a given patient.

      Genetic Information for All?

      "It will be 10 to 20 years before we have something like a complete knowledge of all the genes and their major functions," says Croplin.

      However, some scientists already imagine a gigantic database（数据库）, accessible to everyone via the Internet, where scientists will publish not only the sequence of every gene but also the conclusions that have been reached about how particular genes and their proteins function in the human body.

      "The future is genetic information on databases, so people can do their own research," Venter says. "The goal is to reach both physicians and individuals, and the Internet is allowing this. This will be extremely useful information for many people."

      For example, explains Venter, if you know your genetic code, then research on a genetics database might reveal that you have a genetic tendency for certain diseases, perhaps skin cancer. With that knowledge, you can keep an eye out for symptoms, catch the cancer early if it appears, and correct it with a simple surgery.

      "My hope is that within 10 years every baby will have their complete genome sequenced and on a disk — or whatever data storage medium they're using then — before they leave the hospital," Venter says.  Physicians could save time and perhaps even lives by consulting databases of genetic knowledge before they prescribe treatments, says Brent Greene, president of a genetic research company.

      Greene has been studying the genetic component of throat cancer. He's learned that certain treatments, promising with other forms of cancer, will not work with this form of the disease. He intends to publish his findings on the Web so that doctors won't waste time with these ineffective treatments. (Other companies post some of their findings on the Web for free, but charge a fee for access to other information.) Venter and Greene agree that people with access to such Web-based, genetic databases could, with time and research, come to know more about a particular disease and cutting-edge（最前沿的）treatments than their physician.

      Finally, at least one scientist is concerned that all the talk about scientists fighting disease might give people the wrong idea about their DNA. "People have the perception that genes are full of diseases, but genes are the plans for a normal person," she says. Understanding genes ultimately means that "we will know more about normal functioning," she says, "we will enhance our knowledge about how the human body works."