Biologists Try New Tacks To Teach College Students

REVERSING A TREND: A textbook by Ken Miller of Brown takes an unconventional macro-micro approach. In one controversial pedagogical technique, the conventional order of instruction is reversed. Biologists who teach their subject to first-year college students face a troubling dilemma. Over the past 20 years, the amount of subject matter that they must cover has expanded severalfold. During the same time, by most accounts, incoming students' scientific background and ability to understand theoretical concepts has declined. So freshmen with less preparation than their predecessors must somehow acquire more biological knowledge than those predecessors ever did. Teachers, textbook writers, and publishers have tried several ways to solve the problem. One relatively new approach reverses the conventional order of instruction. It starts with animals, plants, and other familiar objects and works down to cells, molecules, and atoms, rather than the other way round. A more recent teaching technique emphasizes depth over breadth in imparting the essentials of biology and other science subjects. And publishers are increasingly complementing the traditional student-teacher-textbook triangle with CD-ROMs, interactive Web sites, and other accoutrements designed to appeal to the MTV generation. Based on textbook adoptions, the macro-to-micro approach has gained little acceptance so far. But authors and editors continue to tamper with the idea. They also are incorporating it into multimedia efforts to teach biology-efforts that have yielded some successes. Meanwhile, advocates of in-depth approaches-taught this past academic year at Princeton and Stanford universities, among others-concede that it's too early to tell how effective their methods will be for teaching fundamental scientific principles. Supporters of new approaches to teaching freshman biology agree on one point: "What we're doing now in college biology doesn't work," says Bruce Alberts, a biologist who is president of the National Academy of Sciences (NAS). "But changing our system is difficult, because there's so much inertia." According to several editors of textbooks, that inertia manifests itself as a reluctance by teachers to alter their curricula or the textbooks they use. Biologists see several reasons for changing first-year college curricula. Alberts points to the huge increase in the amount of subject matter in recent decades. Teaching every subset of life science, from cell biology to ecology, via genetics, botany, and zoology, "might have made sense 30 years ago," he says. "Now we know so much more that it doesn't." Gerald Audesirk, half of a husband-and-wife textbook-writing team of biology professors from the University of Colorado, Denver, points to the attitudes of some nonscience majors entering college. "There's a subset of students for whom science is a really frightening experience," notes Audesirk, whose spouse and coauthor is Teresa Audesirk. "They have avoided it in high school. In college, they only do it because they have to." David Botstein, a professor of genetics at Stanford University, agrees, with a caveat. "Fewer and fewer students have any background in science," he says. "But this is not the fault of the students; it's the fault of the system. It is no longer fashionable to be an excellent teacher of science." 'EDGY' AUDIENCE: Oregon State's Paul Farber observes that freshmen "students' eyes glaze over" in biology class. 'USEFUL': Michael Mix codeveloped a macro-micro course at Oregon State. Whatever the causes, the effect is obvious to teachers of freshman biology courses. "Students' eyes glaze over," declares Paul Farber, a historian of science at Oregon State University. "They come in a little edgy anyway, because they are less prepared. If you turn them off, you'll never get them back." Farber is one of a small group of science faculty members trying a different way to teach basic biology at the college level. Instead of starting with atoms and molecules and working up the size ladder to cells, plants, and animals, they teach in reverse. They concentrate first on large organisms, which they often relate to ecological issues that strike a chord with several students otherwise uninterested in biology. At Oregon State, Farber along with biologists Michael Mix and Keith King have developed a biology course for nonmajors that takes this type of macro-micro approach. "We found it useful to teach students," says King. "They know the macro objects-deer, elk, grasses. They don't know endoplasmic reticulation." "We do start with a consideration of chemistry and cells, but in a much broader context than normal," explains Mix. "We examine the big questions of the origin of the universe and the Earth, and how new chemicals are formed." Several textbooks, aimed at both majors and nonmajors, are available for freshman biology courses. The following list is not exhaustive. Books for Biology Majors Biology, by Neil A. Campbell, 4th ed., Menlo Park, Calif., Benjamin Cummings, 1996. Biology, by Peter H. Raven and George B. Johnson, 4th ed., Dubuque, Iowa, WCB/McGraw-Hill, 1996. Biology: The Unity and Diversity of Life, by Cecie Starr and Ralph Taggart, 7th ed., San Francisco, Wadsworth Publishing Co., 1995. (8th ed. in press) Life: The Science of Biology, by William K. Purves, Gordon H. Orians, and H. Craig Heller, 4th ed., Sunderland, Mass., Sinauer Associates, 1995. Books for Nonmajors Biology: A Critical Issues Approach, by Robert D. Allen, 1st ed., Dubuque, Iowa, WCB/McGraw-Hill, 1995. Biology Concepts and Applications, by Cecie Starr, 3d ed., San Francisco, Wadsworth Publishing Co., 1997. Biology: Life on Earth, by Teresa Audesirk and Gerald Audesirk, 4th ed., Upper Saddle River, N.J., Prentice Hall, 1996. Biology Today: An Issues Approach, by Eli C. Minkoff and Pamela J. Baker, 1st ed., Dubuque, Iowa, WCB/McGraw-Hill, 1996. Invitation to Biology, by Helena Curtis and N. Sue Barnes, 5th ed., New York, Worth Publishing, 1994. Life, by Ricki Lewis; 3d ed., Dubuque, Iowa, WCB/McGraw-Hill, 1998. The course has had tangible teaching results. According to King, the drop-out rate for the macro-micro course is less than 5 percent in the first quarter. That contrasts with 30 percent or more for traditional nonmajors' biology courses at Oregon State. In 1992, the trio published Biology: The Network of Life (2d ed., Menlo Park, Calif., Benjamin Cummings/Addison Wesley, 1996), a textbook that uses the same approach. "There wasn't a book out there like this; all the books on the market at the time were clones," says King. "Also, we wanted to bring a different mix of topics than in most books, and bring ecology back into the mix." Another book in its second edition follows much the same approach. In Biology: Discovering Life (2d ed., Boston, D.C. Heath, 1994) Brown University biologist Ken Miller and biologist-turned-science writer Joseph Levine aim at nonbiology majors with material that they developed for a college course in general biology during the past decade. In traditional courses, "we were throwing the most abstract and least biological material at them first," notes Miller. "Students were asking: 'When are we going to learn biology?'" In developing the course, Miller ignored traditionalists' objections that students must learn basic principles first. "I studied that, and decided it wasn't true," he reports. "If you look at biological cycles, all you need to know is what an atom is and what a molecule is." Arranging a course that starts with ecology also permitted Miller to establish a logical sequence. "There is a very logical way of setting up a sequence of topics so that mastering one leads to a hunger to learn the next," he states. For example, studies of the growth of populations lead to the idea of effects on other populations, thereby setting up an understanding of concepts relevant to evolution. Miller has a glib answer to comments that students must understand genes in order to understand evolution. "I say: 'Darwin didn't know much genetics, and he did pretty well on evolution,'" he comments. His teaching involves "units of inheritance," which lead directly to genes. The macro-micro course has had an impact at Brown. Since it was introduced, Miller says, the number of students concentrating in biology at the university has almost doubled. The total number of enrollments in biology courses at Brown increased from 1,847 in academic year 1988-89 to 3,581 last year. And the number of bachelor's degrees that the university awarded in biology and related subjects rose from 131 in June 1988 to 287 in June 1997. Nevertheless, several academic biologists object to the macro-micro approach for fundamental reasons. "It's a weird offshoot of the ecology movement that gives students something green," complains George Johnson, a biologist at Washington University in St. Louis who has written best-selling biology texts for college and high-school levels. The macro-micro approach "involves learning based on faith, and that's the wrong way to learn science. It teaches the wrong deep lesson." NAS's Alberts amplifies that thought. "If students don't know chemistry, they won't know molecules," he says. SMALL MARKET: Textbook coauthors Gerald and Teresa Audesirk found scant publisher interest in the macro-micro concept in 1982 In fact, teachers must cope with the fact that biology has its own catch-22: "Everything in biology is understandable as long as you know everything " says Gerald Audesirk. He recalls that he and his wife set out to write a macro-micro book in 1982. However, publishers' surveys showed little interest in the concept. Significantly, the macro-micro books by Miller and Levine and Mix, Farber, and King have had relatively little success according to the criteria of adoptions and sales. "In my experience, this type of book went over big-time with ecologists," says Pat Reidy, biology editor at WCB/McGraw Hill College Publishing, based in Dubuque, Iowa. "The problem was the reality that most professors found it difficult to make the jump from how they taught to teaching in a new way." New approaches also need intensive marketing. "Publishers must know that they're going to lose money in the first three or four editions," says Reidy. "But nowadays, because of the demands of the industry, you have to make it in the first two editions." "Most professors don't want to teach it this way," concurs Jack Carey, biology editor at San Francisco-based Wadsworth Publishing Co. Those professors are the most influential individuals in adopting textbooks. "The students prefer the books to be more exciting," says Julie Keck, a senior marketing manager at WCB/McGraw Hill, "but the professors don't necessarily agree." Publishers are pushing hard to make textbooks more acceptable to a generation used to obtaining information in bite-sized chunks off the Web and CD-ROMs. Increasingly, publishers expect authors to write with flair, to focus on pithy two-page spreads devoted to single subjects, and to help develop bright illustrations for their books. Publishers themselves are setting up three-dimensional animations and Web sites related to individual textbooks, and even chapters. "The Web connection is big," says Carey. Biology teachers, meanwhile, are pioneering courses that emphasize entirely different methods of teaching first-year biology. A group of scientists at Stanford University is about to start the second year of what Botstein calls a "just-in-time" way of teaching premed students. The structured approach starts by focusing on a topic familiar to students and develops the topic to impart basic ideas relevant to the scientific method. The life science course taught in the last academic year, for example, started with the broad topic of heart disease. Classes moved quickly from discussions on how deaths from heart disease are counted to causes of heart disease and the nature of the heart. In that way, the teaching approach exposes the premed students to statistics and probability; the effects on human health of smoking, excess weight, and cholesterol; energy; and "a nontrivial amount of thermodynamics," in Botstein's words. The teaching team followed two principles. "We endeavored never, ever to use the classical way of presenting any theory," Botstein recalls,"on the principle that students have in common the fact that they do not like the classical way." In addition, individual scientists found that they were more competent teaching fundamentals outside their own field "because we were keeping our eyes more on fundamental principles and less on details." At Princeton, geneticist Shirley Tilghman has developed a biology course for nonscientists that takes a similar approach. "We're trying to increase science literacy, but not the number of facts," she explains. "We completely abandoned any idea that we would cover a large body of knowledge. We focus on two or three ideas that have an effect on the lives of students, and explore them in quite a bit of depth." The two-semester course, which started last academic year, examines "origins and beginnings"-of the universe, biological molecules, and the human condition, for example. A chemist and a physicist teach the first semester, while Tilghman and an evolutionary biologist take the second. Rather than labs, the course requires research projects in which students, working in groups of three, have to answer specific scientific questions. Typical subjects include the learning abilities of inbred mice and the behavior of slime molds. After devising their approach to their problem and carrying out the necessary research, the groups must present their results in an end-of-year scientific symposium. "They became scientists," says Tilghman. "Their level of intellectual sophistication amazed me." As a result of the course, many students gained a feel for the role of science in their lives. On the other hand, she says, the course was very staff-intensive and required enormous dedication by faculty and teaching assistants. "This is not an approach I could see working well in a big state school with 400 students in the course," she comments. It does, however, illustrate the steps that the biology community is taking to improve college teaching, for both future biologists and those who might influence biology indirectly via their tax dollars. As NAS's Alberts explains, the new courses and textbooks have one theme in common. "The fundamental issue," he says, "is to teach for understanding." Peter Gwynne, a freelance science writer based in Marstons Mills, Mass., can be reached online at Pgwynne767@aol.com.

Biologists Try New Tacks To Teach College Students

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