dents, demonstrate the importance of the prepared mind, and convey a sense of adventure and excitement.
Scientific discoveries and how they were made can be communicated in many mutually reinforcing ways. First, lectures can be made more vivid and engaging by presenting carefully chosen exemplars of the process of discovery, such as Darwin’s finches, Mendel’s peas, Morgan’s flies, and McClintock’s maize. Roentgen’s discovery of x-rays, von Laue’s and the Braggs’ use of them to reveal atomic structure, and Watson and Crick’s reading of x-ray diffraction patterns in discovering the DNA double helix could be presented as a remarkable sequence of major scientific advances over more than a half century that led to the birth of a new biology. Second, many textbooks contain lucid accounts of the process of discovery that are interwoven with expositions of basic principles. Students should also be encouraged to read the full text of classic papers, which can be made accessible by posting them on the Web. Third, problem sets included in texts or written by instructors for their courses can be choice devices for exploring scientific advances that are inherently quantitative, such as the Hardy-Weinberg equilibrium and Shannon’s measure of information. Fourth, laboratory courses can motivate an experiment by recounting the historical background. For example, a biochemistry laboratory experiment on a glycolytic enzyme could begin with the Buchners’ discovery of fermentation in a cell-free yeast extract, a chemistry laboratory experiment on halogenation with Scheele’s discovery of chlorine, and a physics laboratory experiment on lasers with Einstein’s prediction of stimulated emission. Indeed, a classic discovery can be the basis of an extended experiment in which students explore new terrain, as in the use of the Hill reaction (light-induced electron transfer in illuminated chloroplasts), to find herbicides (an experiment in the interdisciplinary laboratory course described in Case Study #6).
Noteworthy current advances should be presented along with classic discoveries. The covers of major journals often have striking images depicting important research findings. They can be used as evocative starting points in lectures and group discussions to motivate as well as inform students. For example, the recent discovery of fossils suggesting that the divergence between the human and chimpanzee lineages occurred earlier than previously thought (Brunet et al., 2002) would inform and enliven the teaching of human origins, especially if the paper were contrasted with previous estimates of the time of divergence based on molecular clocks.