BIOLOGY TODAY: AN ISSUES APPROACH PROTOTYPE SYLLABUS FOR A ONE-SEMESTER COURSE (revised Dec. 2003) Week 1. Introduction to science and its context. (Chapter 1.) 1. Introduction to the course. Introduction to science and its methods. Characteristics of Living Systems. 2. Science and scientists in a social context. History of science as an organized community of scientists. 3. Ethics and social decision-making. Animal rights as a case in point. DISCUSSION QUESTIONS: What is science? What are its boundaries? Does science have one method or many? Can science be made value- free? Is science exclusively a European invention? On what basis do we say that people have certain rights? What rights do animals have, and why do we recognize certain rights and not others? Week 2. Principles of genetics. Gene structure. Chromosomes. (Ch. 2, plus beginning of ch. 3.) 1. Simple inheritance patterns; dominant & recessive traits, linkage and crossing over. 2. DNA and the basis of inherited traits: DNA and RNA structure; meiosis and mitosis; transcription from genes to RNA; translation from RNA to proteins 3. Chromosomes and genes: inherited metabolic diseases; sex determination; chromosomal variations. DISCUSSION QUESTIONS: How does meiosis differ from mitosis? Does "information" flow only in one direction from DNA to RNA to protein? Is DNA the Master Molecule? Is genetics value-laden? Are there cultural biases in its terminology? Week 3. Human genetics and new uses of genetics. (Ch. 3-4.) 1. Hereditary risks in humans: identifying traits and risks; possible actions. 2. New DNA technologioes: genetic engineering, gene therapy, identification using DNA. 3. The Human Genome Project; genomics & proteomics. DISCUSSION QUESTIONS: What are the differences between a gene and a trait? What are the differences between a trait and a risk? What ethical issues are raised once genetic traits are identified? Should individual genotypes be altered? Should individual phenotypes be altered? Should we try to alter the human gene pool? Is genetic engineering ethical? Is it cost- effective? How is DNA used in identification? What are some forensic applications of DNA? What have we learned from the Human Genome Project? Are new safeguards needed to deal with the new technologies? Week 4. Evolution. (Chapter 5, plus beginning of chapter 6.) 1. The Darwinian paradigm: the dynamic earth (geologic change, fossils); adaptation and selection; patterns of evolution; branching descent with modification. 2. Creationist objections to evolution and scientific responses. Varieties of creationism, including "intelligent design"; evidence for and against creationist claims. 3. Species and modern evolutionary theory: forces of evolution; speciation and isolating mechanisms; biogeography Procaryotic & eucaryotic cells. Six-kingdom classification of organisms; procaryotic kingdoms. DISCUSSION QUESTIONS: What observations did Darwin try to explain? Did his theories explain them adequately? What objections have creationists raised? Are creationist objections made within the boundaries of science? What constitutes evidence for or against creationist claims? Why are species central to modern evolutionary theory? Week 5. Classifying nature. (Chapter 6.) 1. Taxonomic theory. Evolution and diversity of protists, fungi, and plants. 2. Evolution and diversity of animal life. 3. Human evolution; evidence of continuing evolution today. DISCUSSION QUESTIONS: How are classification schemes developed? Why did multicellularity evolve so many times? What major steps occurred in the evolution of each group, and why? What evidence do we have that humans evolved, or that evolution is still occurring? Week 6. Human variation; sociobiology. (Chapters 7-8.) 1. The genetic basis of human variation. Concepts of population and race. Variation within and between populations. Population genetics and population ecology: Genetic drift. 2. Adaptive value of many human variations. Specialization and adaptation. Forces of evolutionary change: disease as an agent of selection; traits protecting against malaria, traits related to vitamin D. 3. Sociobiology and its paradigm. Social organization is adaptive. Altruism; Eusociality Reproductive strategies: asexual and sexual reproduction. DISCUSSION QUESTIONS: What are races? Do races exist, and how do we define them if they do? Is it possible to recognize races without being a racist? What are the assumptions that socio- biologists commonly make? Which assumptions are necessary (in the sense that you cannot study sociobiology without making them)? How are these assumptions justified? Why do males and females follow different reproductive strategies in many species? How do these reproductive strategies complement one another? FILMS make an excellent addition here, as local availability permits. We recommend devoting a class period to films if at all possible. Week 7. Sociobiology (continued); population growth; reproductive biology and birth control. (Chapters 8-9.) 1. Primate sociobiology and human sociobiology. 2. Human population growth and its control. Demography; r- and K-selection. 3. Reproductive anatomy and physiology. Birth control methods. DISCUSSION QUESTIONS: How far can the findings of sociobiology be extrapolated from other species to humans? Are humans fundamentally different, and, if so, why? Do we know how fast human populations are growing? Can we reduce the rate of human population growth? What are some social implications of urging population control on other populations? Why are different birth control methods appropriate to different people or different societies? MIDTERM EXAMINATION (for schedules that have a single major midterm plus a final). Week 8. Nutrition and health. (Chapter 10.) 1. The processes of digestion and absorption. Metabolism and energy; cell membranes; membrane transport. 2. Nutrients that the body needs: molecular structures and characteristics of carbohydrates, lipids, proteins. The circulatory system and cardiovascular health. 3. Nutritional inadequacies and the problems that they cause. Eating disorders. Protein deficiency. Micronutrient malnutrition. Variations in nutrition around the world. DISCUSSION QUESTIONS: What is each nutrient needed for? What happens when there is an inadequate supply? What happens when the supply is excessive? Which problems are of greatest concern in the population around you? Which problems are of greatest concern in other populations? Week 9. Plants and crops. (Chapter 11.) 1. Plant pigments and photosynthesis. Energy and metabolism. Plant structures. Plant fluids and their flow. 2. Plant products other than carbohydrates. Nitrogen and its compounds in plants. Sources of nitrogen for plants. Nitrogen cycle. Communities, ecosystems and the biosphere. 3. Improving crop yields. Fertilizers, soil conservation and irrigation. Pest control: trophic pyramids and biomagnification. Genetic engineering. DISCUSSION QUESTIONS: In chapter 10 we studied the Krebs cycle and other processes of cell metabolism. What do these processes have in common with photosynthesis? What differences exist among these processes? What are some of the many ways in which plants and their products may be considered useful? What sorts of value judgements are embedded in terms like "useful"? How can crop yields be increased? Will methods that work in some places always work in other places? What limitations exist to world- wide adoption of agricultural practices that increase crop yields? Why might a pesticide like DDT be used in some places and banned in other places? What are some long-term consequences of pesticide use? What are some alternatives? Should genetic engineering be used to improve plant species? What risks do we need to test for? Week 10. Stem cells, cell division, and cancer. (Chapter 12.) 1. Cell division and its control. Evolution of multicellularity. Cell differentiation and tissue formation. Cellular detection of environmental stimuli. Gene expression and control of cell division. Stem cells and their possible uses and risks. 2. How cancers arise. Possible mechanisms and known risk factors. Oncogenes and proto-oncogenes. Mutagenesis and carcinogenesis. 3. Cancer prevention and treatment: Risk factors. Smoking and alcohol, nutrition. Testing of mutagens: The Ames test. DISCUSSION QUESTIONS: How is cell division controlled? What are stem cells, and why are they important? What evidence can implicate something as a risk factor for cancer? as a cause of cancer? How do we evaluate disputed claims? Bruce Ames says that we are surrounded by thousands of natural as well as artificial carcinogens, but that we should not be alarmed over this fact-- what does he mean by this? Week 11. The nervous system. (Chapter 13.) 1. The brain and its parts. Neurons and nerve impulses. Sense organs. 2. Neurotransmitters and their malfunctions. Diseases of the brain. 3. Circadian rhythms and sleep. Learning and memory. DISCUSSION QUESTIONS: What evidence do we have that certain parts of the brain govern certain activities? What evidence allows us to name a particular neurotransmitter as responsible for a particular type of malfunction? Can we distinguish between neurological and psychiatric disorders? How might we investigate why depression occurs more often among women than among men? It is ethical to give drugs that alter personality? What rights do Alzheimer's patients have in specifying how and when their lives should be terminated? Brain wave patterns change in people who are sleep-deprived; what does this tell us about the function of brain activity during sleep? Week 12. Drug use & abuse. Stress. Mind and body. (Chapters 14-15.) 1. Drugs in general. Drug uptake by various routes: via gas exchange in the lungs, via absorbtion from the digestive tract, and via blood circulation in the placenta. Drug elimination: the excretory system. Drug interactions. 2. Psychoactive drugs and their activity. Cellular mechanisms of drug action; receptors. Drug abuse and addiction: Effects on individuals. Effects on development. Effects on populations. 3. Mind and body: The immune system as a sense organ. Feedback loops. The neuroendocrine system. The autonomic nervous system. The stress reaction. Stress and immunity: mechanisms; evidence. Individual variation. Theories of health and disease. DISCUSSION QUESTIONS: What are some reasons why the same drug dose might affect different individuals differently? What causes certain drugs to be addictive? What evidence is needed to conclude that a particular drug is addictive? Pick a drug for discussion that is currently illegal or legally regulated; what evidence would cause you to change your mind one way or the other on the question of tightening or loosening restrictions on the use of this drug? What relationship does the "mind" bear to the neuroendocrine and immune systems? How can this relationship be studied? What statements about the mind are falsifiable? Week 13. HIV/AIDS and other infectious threats. (Chapters 16-17.) 1. AIDS as a disease. HIV and the processes that lead to AIDS. Viruses and their life cycles. Discovery of HIV; evidence that it causes AIDS; how HIV infection leads to AIDS; testing for HIV and AIDS. 2. Avoiding HIV and AIDS. Reducing the incidence of HIV infection in populations. 3. Other infections and their threats: characteristics of pathogens; evolution of virulence; factors favoring the spread of pathogens; bioterrorism. Sexually transmitted diseases and their increased spread. New transmission risks for foodborne diseases, for water- borne diseases, and for vector-borne diseases. Bacterial diseases: plague, tuberculosis, botulism, etc. Viral diseases: herpes, papilloma, West Nile, etc. Other diseases: giardiasis, leishmaniasis, etc. DISCUSSION QUESTIONS: How good is the evidence that HIV causes AIDS? Why are some people unconvinced? Why is it so difficult to study HIV infection? What technical and ethical limitations make it difficult to study the effectiveness of drugs that might help prevent AIDS? Are some people naturally more susceptible or more resistant to AIDS? What are the most effective ways to reduce the incidence of AIDS, and what objections might be raised to these measures? What new and changing factors are responsible for the spreading of new disease threats? What new diseases are spreading, and how? What old diseases are spreading once again, and why? How can we control these various new threats? Week 14. Biodiversity, threatened habitats, and the biosphere. (Chapters 18-19.) 1. Biodiversity: extinction and endangered habitats; conservation biology; communities and ecosystems; biomes. 2. Pollution and threatened habitats: desertification; rainforest diversity and rainforest destruction. Pollution on a local and regional scale; acid rain; bioremediation and water treatment. How can habitats and biodiversity be protected? 3. The biosphere and the atmosphere: Earth's atmosphere and its history; Origin of life; life's impact on the atmosphere; Chlorofluorocarbons and ozone layer destruction; Carbon dioxide and global warming. DISCUSSION QUESTIONS: What is biodiversity, and how is it threatened? How (and in what circumstances) has extinction occurred in past geologic ages? How would you evaluate conflicting theories regarding past extinctions? Are the extinctions occurring today similar to or different from extinctions in the past? Does habitat have intrinsic value, or only instrumental value? Will it be easy or difficult to get both wealthy and poor people to help protect biodiversity? Is there any way around the problem of NIMBY ("not in my back yard") thinking? How did life on Earth originate? How do we know that Earth's atmosphere has changed? What is the evidence that life was responsible for a major portion of this change? How can acid rain in one place be controlled if its causes are someplace else (e.g., in a different country)? Why is the ozone layer important? What causes damage to this layer, and how? Is there a way to repair the damage to the ozone layer? What causes global warming? How can global warming be mitigated? FINAL EXAMINATION. MISCELLANEOUS NOTES AND HELPFUL HINTS FOR INSTRUCTORS: 1. We assume that the above syllabus will need to be locally modified to adjust for differing semester lengths, numbers of meetings per week, and so forth. 2. If possible, we recommend weekly discussion sessions in addition to lectures. There are several possible ways of doing this. For example, students could be arranged into study groups and assigned in rotation the task of presenting material, after which all students in each group ask questions and check on each other's understanding. Instructor-led discussions are another possibility. In any event, we recommend that these discussion sections be small groups. Some instructors may even run the whole course through these discussions, without traditional lectures at all. Many additional thought questions for discussion may be found at the end of each section within each chapter. 3. The discussion questions listed on the preceding pages, as well as the Thought Questions in each section, may also be used as written critical thinking assignments. One or more questions each week may be assigned as the subject for short position papers or similar short writing assignments. The ensuing discussions often flow more smoothly if students have individually researched and/or thought about these or similar topics. 4. You may ask each student to keep a notebook or folder of clippings from newspapers and popular magazines related to course topics (or to science in general). It may be profitable to discuss some of these articles publicly in class near the end of the semester. 5. The scheduled frequency of long exams and shorter quizzes varies greatly from place to place. We fully expect individual instructors to adjust the above schedule to suit their own needs. 6. Although it is possible to teach this course without a lab, we recommend that a lab be included. We welcome hearing about any particularly successful laboratory experiences. PERMISSION IS HEREBY GRANTED to instructors who have adopted the book BIOLOGY TODAY for classroom use to download, modify, and use these notes as needed to aid them in in their teaching. Students of such instructors may likewise use and modify these notes as study aids.