Asking About Life - Hardcover

Tobin, Allan J.; Dusheck, Jennie

Hardcover

ISBN 10: 003072046X ISBN 13: 9780030720468

Publisher: Cengage Learning, 1997

Synopsis

Asking About Life is an introductory biology textbook for first-year college students and other interested readers. The strengths of the book include engaging stories about the process of science, an emphasis on experimentation, and stylish prose. It is unusually current for an introductory text, and has a striking art program. The authors, a distinguished research scientist and a professional science writer, use a unique approach to biology that emphasizes questions, experimentation, and principles as well as the human drama that has allowed scientists to arrive at these principles. The text introduces biology as an engaging human quest fraught with conflict and illuminated by discovery. The authors accomplish this by telling stories of individuals struggling against ignorance, ideology, and other barriers to understanding. This new approach brings to the classroom the human drama needed to sustain student interest, without the dreary emphasis on disease and suffering that some biology textbooks use as a "human" approach. Subjects for profile range from outspoken mavericks such as Nobel Laureate Kary Mullis and immunologist Polly Matzinger to quiet and tenacious researchers such as geneticist Barbara McClintock and Charles Darwin. The profiles feature scientists whose flaws, passions, and independence play a significant role in the way they do science. In this way, Asking About Life shows that science is a social endeavor and that discoveries may hinge on which researchers work in groups and which ones work in isolation. This approach to teaching biology gently engages the reader in the process of doing science and humanizes both biologists and biology. Asking About Life also emphasizes that science is primarily a series of questions. The way in which biologists ask questions and attempt to answer those questions is the book's central theme. Each chapter is structured around a series of questions and answers that engage the reader step by step in the process of discovery. Readers learn that sometimes the greatest contribution a scientist can make is not the answer to an important question, but the question itself. The authors of Asking About Life ask: What questions have the most engaged biologists argued about in the past? How have past controversies led to our current understanding of biology and to the questions that fascinate today's biologists? Finally, they ask, what are the important unanswered questions in biology? In keeping with this emphasis on asking and answering questions, Asking About Life describes the experiments that provided the answers to important questions in biology. Students who have learned the experimental underpinnings of current concepts are in a better position to assimilate new information as it emerges(whether in later classes or in the daily news. Asking About Life is unusually current for an introductory text, using up-to-date examples throughout and grappling with topical issues such as gene therapy, the cloning of humans, the role of dietary salt in hypertension, and the role of nicotine in heart disease. These examples engage not only the student but the instructor as well. The authors operate from the premise that when an instructor is intellectually engaged with the text, students benefit.

About this title

About the Author:

Allan J. Tobin is Director of the UCLA Brain Research Institute. He holds the Eleanor Leslie Chair in Neuroscience at UCLA, where he is both Professor of Neurology and Professor of Physiological Science. Tobin is also Scientific Director of the Hereditary Disease Foundation (HDF), where he helped organize the consortium that identified the gene responsible for Huntington's disease. Both at UCLA and at HDF, he has encouraged the application of cell biology and molecular genetics to disorders of the brain.

Tobin's undergraduate degree is in literature and biology (MIT, 1963), and his doctoral degree is in biophysics, with an emphasis on physical biochemistry (Harvard, 1969). Tobin did postdoctoral work on cell surface molecules at the Weizmann Institute of Science, in Israel, and on red blood cell development at MIT. At UCLA, he has an active research laboratory that studies the production and action of GABA, the major inhibitory signal in the brain. These studies may eventually lead to new therapeutic approaches to epilepsy, Huntington's disease, and juvenile diabetes. Tobin is the recipient of a Jacob Javits Neuroscience Investigator Award from the National Institute of Neurological Disorders and Stroke.

For more than 25 years, Tobin has taught introductory courses in cell biology, molecular biology, developmental biology, and neuroscience. He is the recipient of a Faculty Teaching and Service Award and is regarded as an excellent and highly interactive teacher.

Excerpt. © Reprinted by permission. All rights reserved.:

CHAPTER 1 THE UNITY AND DIVERSITY OF LIFE Bacteria: enough to give you an ulcer In 1984, an obscure Australian physician named Barry Marshall secretly performed a dangerous experiment that would ultimately deprive some of the world's largest corporations of billions of dollars (Figure 1-1). Marshall's radical idea was born in 1979 when his colleague and friend J. Robin Warren, a pathologist at Royal Perth Hospital, in Australia, noticed that tissues from patients with ulcers and other stomach problems were often infected with bacteria. To find even one bacterial infection in the stomach would have been strange; to find dozens of stomach infections was bizarre. The human stomach secretes acid so concentrated that few organisms can survive it for more than a few minutes, let alone live and reproduce in it. Yet Warren found bacteria flourishing there. Warren's discovery suggested an alternative to doctors' longstanding belief that ulcers are caused by excess stomach acid. Ulcers, every medical textbook reported, were caused by the oversecretion of stomach acid in people with overanxious, frustrated personalities. Such personality problems were thought to be aggravated by the stressful pace of modern life. But if a bacterium could infect the stomach, Marshall and Warren realized, maybe it could cause ulcers. Intrigued by this idea, Marshall began ordering biopsies for all his patients with stomach problems. He found that nearly every patient with ulcers was infected with the same bacterium. The most common kind of ulcer is a peptic ulcer, an open wound located where the stomach joins the small intestine, at the bottom of the stomach. The word peptic comes from the Greek word peptein, to digest. Nearly one in ten adults has a peptic ulcer. Some people with ulcers feel no discomfort, but most experience at least mild pain, and many suffer excruciating pain for weeks at a time throughout their adult lives. In rare cases, blood may pour from the wound so freely that the victim bleeds to death. The standard treatment for ulcers had always been a high-fat, bland diet, tranquilizers, psychotherapy, and, in severe cases, surgery. But mainly doctors prescribed antacids-lots of antacids. Antacids are the biggest-selling prescription drugs in the world. In 1992, Americans bought $4.4 billion worth of the drugs. Prescription antacids are remarkably effective at controlling the secretion of stomach acid, but remarkably ineffective at controlling ulcers. Ninety-five percent of ulcer patients have a new ulcer within two years of treatment. That means people with ulcers take the $100-a-month antacids almost continuously. In a lifetime, an ulcer-sufferer can spend tens of thousands of dollars on antacids. Yet, if ulcers were caused by a bacterium, a two-week course of antibiotics might permanently cure millions of people of what would otherwise be a lifetime of suffering. If Marshall's hunch was right, he had very good news, although not for the companies that were selling antacids. Marshall, however, had insignificant credentials as a doctor and none as a researcher. In 1980, he seemed to have no more chance of selling his idea to the biomedical community than his bacteria had of flourishing in the corrosive environment of the stomach. Nevertheless, in 1983, Marshall presented his hypothesis at a scientific conference in Brussels. His presentation was a disaster. He was unknown, he was young, inexperienced, and overexcited, and he had a seemingly screwball idea. "He didn't have the demeanor of a scientist," later recalled Martin Blaser, professor of medicine at Vanderbilt University. "He was strutting around the stage. I thought, this guy is nuts." When it was over, his audience of eminent medical researchers shifted uneasily in their seats, embarrassed. A few laughed. They couldn't believe he was serious. Most bacteria can barely survive a brief passage through the stomach. How could they flourish there for months or years? Besides, Marshall had no scientific evidence to back up his claim. Maybe, his audience told him, the bacteria had contaminated the stomach samples after the stomach tissues had been removed. Or maybe the bacteria were harmless and unrelated to the ulcers. Or maybe the bacteria were able to colonize the stomach as a result of the ulcer. Marshall realized that the only way to settle these questions was to study the bacterium in an experimental animal. He needed to find an animal whose stomach could be infected with the bacterium. After returning to Australia, he began feeding the bacteria to rats. The bacteria died in the rats' stomachs without having any effect. He fed the bacteria to pigs, with the same result. Now he began to wonder, could the bacteria really infect a stomach? Maybe the researchers in Brussels had been right to laugh at him. Desperate to prove that he was no nut, Marshall did something highly unusual and not very scientific. First, he had a stomach exam and biopsy to make sure his stomach was healthy. Then he made an "ulcer bug" cocktail, containing at least a billion bacteria, and, in a few swift gulps, drank it down. The cocktail was enough, he hoped, to infect his stomach. He told no one ahead of time-not the medical ethics board at the hospital, not his wife. They wouldn't have approved, he knew. At first, nothing happened. Then, eight days later, nausea woke him early and he vomited. For another week he was tired, irritable, and hoarse. He had headaches and foul breath. A second stomach exam and biopsy showed that his stomach was inflamed and swarming with bacteria. By the third week, Marshall was lucky enough to have recovered completely. He had not proved that the bacterium could cause ulcers, or even that it could infect the stomach for years at a time. But he had done something that strongly suggested that the bacterium, still unnamed at the time, could at least infect a healthy human stomach-one that didn't already have an ulcer. In time, other, more-established researchers began to take an interest. Mainly they were interested in proving Marshall wrong. But by the end of the 1980s, the evidence that the bacterium could infect the stomach was unassailable. In 1989, the bacterium was named Helicobacter pylori because of the bacterium's helical shape and because it was known to colonize the pylorus, near the stomach's exit (Figure 1-2). By 1993, definitive studies by other researchers had shown that some 80 percent of ulcers were caused by H. pylori, and were treatable with antibiotics. Drug companies, initially somewhat negative about Marshall's idea, began to see a silver lining in the cloud the Australian had created. It was true that people treated with only $20 worth of antibiotics had a relapse rate of only about five to ten percent-which meant an ulcer sufferer would spend thousands of dollars less on drugs. On the other hand, infection by H. pylori turned out to be one of the most common bacterial infections in humans in the world-infecting up to half of all people worldwide. And mounting evidence suggested that chronic infection by H. pylori not only caused ulcers but also increased the risk of developing stomach cancer. Here was a market for antibiotics consisting of billions of people. Marshall's cloud definitely had a silver lining. By 1993, drug companies were hastily developing new diagnostic tests for H. pylori and new antibiotics to treat the infection. Biotechnology companies were trying to develop a vaccine, to be given in childhood, that would protect against H. pylori, ulcers, and maybe even stomach cancer, a leading cause of death in Asia. In early 1994, experts at the National Institutes of Health declared antibiotics the official treatment for ulcers. For the first time, doctors began treating their patients with antibiotics that would offer a permanent cure. Change came slowly. By 1996, only one-third of doctors were prescribing antibiotics for ulcer patients. The rest continued to prescribe antacids only. Marshall ultimately won acceptance as a scientist, earning a position on the faculty at the University of Virginia Medical School. He succeeded in part because he possessed many of the attributes of a good scientist. He had curiosity, intelligence, vision, and the dogged determination to pursue an idea-even when his stubbornness made him appear foolish. Perhaps most important, Marshall displayed an unusual independence of thought that allowed him to pursue an idea unimaginable to more dogmatic thinkers. In this book we will meet many scientists who are as curious, independent, and stubborn as Marshall. Some are occasionally impulsive, like Marshall. Others are careful thinkers, who take years to reach their conclusions. Most work long hours for years on end. A very few seem merely to play at science, reaping brilliant discoveries from a few hours work. We'll see some of them risk their reputations to defend the ideas they believe in. A few even lose their lives. Right or wrong, all are fascinated by questions about what makes living things tick. Good biologists, like other scientists, are people who are intensely engaged with life. In this first chapter of Asking About Life, we will examine two important aspects of biology, the science of life. We will see how biologists try to answer questions about life, and we will try to define life itself. What makes life what it is? How do biologists study it? TABLE OF CONTENTS: Chapter 1. The Unity and Diversity of Life Part I: Chemistry and Cell Biology Chapter 2. The Chemical Foundations of Life Chapter 3. Biological Molecules Small and Large Chapter 4. Why Are All Organisms Made of Cells? Chapter 5. Directions and Rates of Biochemical Processes Chapter 6. How Do Organisms Supply Themselves with Energy? Chapter 7. Photosynthesis: How Do Organisms Get Energy from the Sun? Part II: Genetics: The Continuity of Life

Chapter 8.

Cell Reproduction Chapter 9.

From Meiosis to Mendel Chapter 10. The Structure, Replication and Repair of DNA Chapter 11. How Are Genes Expressed? Chapter 12. Jumping Genes and Other Unconventional Genetic Systems Chapter 13. Genetic Engineering and Recombinant DNA Chapter 14. Human Genetics Part III: Evolution Chapter 15. What Is the Evidence for Evolution? Chapter 16. Microevolution: How Does a Population Evolve? Chapter 17. Macroevolution: How Do Species Evolve? Chapter 18. How Did the First Organisms Evolve? Part IV: Diversity Chapter 19. Classification: What's in a Name? Chapter 20. Prokaryotes: How Does the Other Half Live? Chapter 21. Classifying the Protists and Multicellular Fungi Chapter 22. How Did Plants Adapt to Dry Land? Chapter 23. Protostome Animals: Most Animals Form Mouth First Chapter 24. Deuterostome Animals: Echinoderms and Chordates Part V: Ecology Chapter 25. Ecosystems Chapter 26. Communities: How Do Species Interact? Chapter 27. Biomes and Aquatic Communities Chapter 28. Populations and the Human Place in the Biosphere Chapter 29. The Ecology of Animal Behavior Part VI: Structural and Physiological Adaptations of Flowering Plants Chapter 30. Structural and Chemical Adaptations of Plants Chapter 31. What Drives Water Up and Sugars Down? Chapter 32. Growth and Development of Flowering Plants Chapter 33. How do Plant Hormones Regulate Growth and Development? Part VII: Structural and Physiological Adaptations of Animals Chapter 34. Form and Function in Animals Chapter 35. How Do Animals Obtain Nourishment from Food? Chapter 36. How Do Animals Coordinate Cells and Organs? Chapter 37: Blood, Circulation, and the Heart Chapter 38. How Do Animals Obtain and Distribute Oxygen? Chapter 39. How Do Animals Manage Water, Salts, and Wastes? Chapter 40. Defense: Inflammation and Immunity Chapter 41. The Cells of The Nervous System Chapter 42. The Nervous System and the Sense Organs Chapter 43. Sexual Reproduction Chapter 44. How Do Organisms Become Complex?

About this edition

• Publisher: Cengage Learning
• Publication date: 1997
• ISBN 10: 003072046X
• ISBN 13: 9780030720468
• Binding: Hardcover
• Edition number: 1
• Number of pages: 962