Relevant material from MIT's introductory courses to support students as they study and educators as they teach the AP Biology curriculum.

Evolution has resulted in changes in the sizes and forms of organisms. Everything about the biology of an animal, including its physiology, anatomy, and ecology, is influenced by its body size. Frequently there seem to be limits on the sizes that different organisms can attain, even when larger size might be thought to be evolutionarily advantageous. Often an increase or decrease in size is correlated with a change in proportions. Understanding the significance of a particular morphology or interpreting the factors that underlie a particular evolutionary trend involve studying the relationships that exist among size, shape, and function. This lab introduces allometry, the study of size and its consequences, using celery and woodlice as subjects.

This is a laboratory exercise appropriate for sophomore level students. No prior math is required, and lab exercise can be adapted if computer facilities are available.

By manipulating a simple kinematic model representing the leg and foot, students can get hands on information about the interaction of bones and muscles in humans. Having worked with the model, they then are able to predict and analyze the properties of bone/muscle systems in other vertebrates and understand how these systems have become modified during the course of evolution for a particular life style. By the end of the exercise, students have learned both traditional information (cellular structure, names of bones, taxonomy of vertebrates) and how to project the knowledge they gained from working with a model to the biological world.

Intelligent Design continues to be a hot political and educational topic in some parts of the country. This discussion case study uses the dramatic setting of a public school board as it considers whether district science teachers should be made to read a statement to their classes identifying Intelligent Design as a competing theory to evolution that is worthy of scientific consideration. The relevant statement is in fact the one that was at the center of the 2004 controversy in Dover, Pennsylvania. This case would be appropriate in general biology or advanced courses where the focus is on evolution.

The discovery of the platypus had the scientific world in an uproar and kept it tantalized for decades. Here was the strangest animal ever seen. How was one to classify it? It had fur. So, was it a mammal? But then what to make of its duck-like bill? And how did it produce and suckle its young? Based on the book by Ann Moyal titled Platypus: The Extraordinary Story of How a Curious Creature Baffled the World, the case focuses on classification and evolution and models the scientific process, with scientists arguing, debating, collecting more information, and revising their opinions as more data become available.

Unlike most population genetics labs, which involve simulations with beans or beads, this lab provides an opportunity to study a population of living organisms. Using Bar and wild-type Drosophila, students compare allele and genotype frequencies to Hardy-Weinberg expectations. Because the Bar mutation in Drosophila is sex-linked and incompletely dominant, students can determine the exact genotype of a fly from its phenotype. These data are evaluated to determine which (if any) of the five Hardy-Weinberg assumptions have been violated. This real-data approach allows students to appreciate the value of this null model and helps the instructor to discover and correct students' misunderstandings of the model.

At what point in evolutionary development does a group of individuals become two distinct species? This case addresses that fundamental question by asking students to decide whether apple maggot flies are distinct as a species from hawthorn maggot flies. In making their decision, students examine the different models of speciation and consider the primary forces that effect evolutionary change. Developed for an advanced undergraduate course in evolutionary biology, it would be appropriate for any biology course in which students are taught about the models of speciation. It could also be used in a general ecology course in which students consider the distribution and use of resources leading to niche specialization or in a genetics course if restrictions in gene flow are taught in the context of speciation.

This case is based on Kate Chopin's short story "Desiree's Baby," a tragic tale of race and gender in antebellum Louisiana first published in 1893. Students read the story and then answer a series of questions about the genetics and evolution of skin color. The case was developed for a general biology course organized around the general theme of evolution. It could also be used in anthropology and biology courses for non-majors.

This case examines the hormonal control of the development and maturation to adulthood and the role of stress hormones in that developmental process. The case was adapted from results summarized in Maggioncalda and Sapolsky's (2002) article in Scientific American. It presents evidence for why an unusual adaptation for reproduction in subordinate male primates may have evolved as a means of reducing stress. Students are presented with data from the published studies and asked to analyze and interpret the results to formulate hypotheses. Initially developed for an upper division endocrinology course, the case has been used in an upper division comparative anatomy-physiology course, and could be used in an animal behavior or behavioral ecology course.

This interrupted case study focuses on the research of Dr. Beatrice Hahn, who investigates DNA sequences in chimpanzee droppings in order to explore the origins of the human immunodeficiency virus (HIV). Students first consider the types of data that can be gained through collecting chimpanzee feces and studying the behavior of these animals. Students then apply this information to learn more about microevolution when they compare DNA sequences. Finally, students learn about ELISA tests and consider the role of basic and applied science. This case study is appropriate for an introductory biology course for non-majors or majors.

This "clicker case" is a redesign of a case, also in our collection, by Robert H. Grant titled "A Strange Fish Indeed: The 'Discovery' of a Living Fossil." The case follows the story of Marjorie Courtenay-Latimer and her discovery of the coelacanth, a fish of considerable evolutionary interest. It uses the story as a springboard to explore evolutionary concepts and the scientific method. It has been reformatted to use student personal response systems ("clickers") and a PowerPoint presentation (~4.2MB), and further emphasizes the role of Ms. Courtenay-Latimer. The case is designed for large introductory biology courses.

Why has it been easier to develop a vaccine to eliminate polio than to control influenza or AIDS? Has there been natural selection for a 'language gene'? Why are there no animals with wheels? When does 'maximizing fitness' lead to evolutionary extinction? How are sex and parasites related? Why don't snakes eat grass? Why don't we have eyes in the back of our heads? How does modern genomics illustrate and challenge the field? This course analyzes evolution from a computational, modeling, and engineering perspective. The course has extensive hands-on laboratory exercises in model-building and analyzing evolutionary data.

This "clicker case" about female mimicry in spawning salmon was developed for an introductory-level, non-majors biology course to help address one of the most common misconceptions that students have about natural selection, namely, that only the "strong" survive and reproduce. Female mimicry is an alternative male reproductive strategy. As observed in spawning salmon, some males assume certain female characteristics that enable them to remain close to reproducing females without being viewed as competition by more dominant males. Students learn about concepts of natural selection, including overproduction and differential reproductive success, as well as patterns of natural selection. The case is presented in class via a PowerPoint presentation (~3MB) that is punctuated by multiple-choice questions students answer using personal response systems ("clickers").

This workshop, which is half wet lab and half Internet lab, uses DNA sequences to examine the relatedness of different species. DNA from several insect and/or fish species are compared. This chapter includes instructions for extracting DNA from gels and making PCR products. We prepare PCR products to send to a computerized automated sequencing facility. (No radioisotopes are used in this sequencing!) We recover sequence from the facility over the Web as four-color graphics on a computer screen and as text. We make pair-wise DNA sequence comparisons between species with BLAST2 and multi-species comparisons with MultAlin. We see substitutions, insertions, and deletions. Then we make a distance-based evolutionary tree with GeneBee.

In this "clicker case," students learn about natural selection through the research of Peter and Rosemary Grant and colleagues on the finches of the Galapagos Islands. Students are presented with data in the form of graphs and asked to determine what is happening to a population of finches as the changing environment produces changes in the shape of the finches' beaks. This case is suitable for any size course in introductory biology, ecology, or evolution, and does not require any pre-requisite knowledge of evolution or natural selection. The case consists of a PowerPoint presentation (~4.5MB) punctuated by questions that students answer in class using "clickers." It can be adapted for use without these technologies.

In this role-playing case study, students attempt to determine the identity of a variety of human fossils based on characteristics described during a "quiz show." The case was designed to be used in a general biology class for freshman students where the focus is on evolution. It could also be used in an anthropology or paleontology course.

This "clicker case" teaches students about the distinction between proximate and ultimate causes of behavior using the fascinating courtship and mating rituals of the Australian redback spider. The case is presented in class via a PowerPoint presentation (~3MB) punctuated by multiple-choice questions that the students answer using personal response systems, or "clickers." It could be adapted for use without these technologies. Although developed for a general biology class, the case would also be suitable for use in non-majors introductory biology or behavioral ecology courses.

This directed case study on a genetic disorder was developed for an exam on genetics for a general biology course. The case is based on an article by scientist and author Jared Diamond titled "Founding Fathers and Mothers" that appeared in Natural History magazine in June 1988. In the article, Diamond illustrates the significance of the "founder effect" in small isolated populations like the one described in this case.