Evolution Adventure! Study Sheets for the Natural Mysteries exhibit These four-page study sheets are designed to help engage learners in the evolution stories of one or two organisms while exploring the Natural Mysteries exhibit at the Museum of Science, Boston. Each Evolution Adventure cover page presents a picture of something to find within the exhibit. The next pages include an activity, background content on the connection between the activity and the study of evolution, and common mis- conceptions. The final page provides additional activities for home or school, standard connections, and references. Birds 2 Birds show us that behavior evolves. Geese 6 Understanding adaptive radiation with geese. Hippos and Whales Hippos and whales help us understand how morphology 10 can be misleading. Leopards and Jaguars 14 Defining a species with leopards and jaguars. Rhinos 18 Envisioning extinct animals with rhinos. Trilobites 22 Overview: what is evolution? Turtles 26 Turtles can teach us about natural selection Woodchucks 30 Woodchucks help us understand symbiosis. Museum of Science, Boston Birds show us that behavior patterns evolve Turdus migratorius (American Robin) Icterus galbulae (Baltimore Oriole) Hylocichla musfelina (Wood Thrush) Museum of Science, Boston Explore the connections Scientists can study fossil remains, anatomy, and DNA to find out how animals evolved. Likenesses in body shape and genetics indicate that robins and thrushes share a common ancestor. However, DNA studies and comparative anatomy do not inform us about differences in animal behavior, which is some- times the only trait that separates closely related species. Nest building is one such behavior that scientists can demonstrate has evolved over time in various ways among different species.2 Since American Robins and Wood Thrushes live in the same general area as Baltimore Orioles, the same materials used for building nests are available to all the birds. But, thrushes and orioles are choosey. These birds decide on par- ticular materials and arrange them in a particular pattern. Because these birds are not taught to build nests by their parents, we can deduce that their nest-building technique is actually a sequence of evolved behaviors influenced by their genes.3 Birds held in captivity supply us with another piece of evidence indicating that birds are born with the predisposition to build nests in certain ways. A robin raised by human hand—without exposure to other robins—will build a typical robin nest. Bird researchers speculate on the adaptive value of various nest shapes. They ask themselves: why do birds build nests in such different ways? did their nest-building techniques help them beat out competitors? They also wonder what types of selection pressures could have caused other evolved bird behaviors, like migration and vocal patterns. Concepts and misconceptions COncePT • While some human behaviors are learned, others are inherited genetically. There are some behaviors that have aspects of both learned and genetic control. MIscOncePTIOns Many people mistakenly think that: • Human behavior is inherited in different ways than the behavior of other animals. Many people may not recognize that some human behaviors are under genetic control. They also may not realize that other animals have the ability to learn behavior patterns just as people do. • Animals are aware of the significance of their behaviors. This is called anthropomorphism. An animal’s insight may exist, but should not be assumed. Exhibit scavenger hunt Go to the Natural Mysteries exhibit, located in the Blue Wing, Lower Level, and find an American Robin, a Wood Thrush, a Baltimore Oriole, and the nests that they make. 1. Draw a circle around the two nests that are similar. Wood Thrush Nest Oriole Nest Robin Nest 2. Exit Natural Mysteries and turn left to enter A Bird’s World. Find the Baltimore Oriole and the Wood Thrush in the broadleaf forest cabinet. Find the American Robin in the cities and suburbs cabinet. 3. Use the touch screens to investigate the calls, habitats, and diets of each bird. Additional activities for home or school 1. a. Consider the various factors influencing appetite. First, perform a test taste. Use PTC taste paper (available from Connecticut Valley Biological Supply) NOTE TO TEACHERS to test your student’s ability to taste PTC. PTC paper is made out of a This activity relates to the nontoxic chemical—phenylthiocarbamide—used in genetic research. This following Massachusetts exercise shows that some people are genetically predisposed to notice Learning Standards: some tastes, while others do not notice them. Pre K – 2 • Heredity b. Next, take a survey to consider what your students’ favorite foods are and • Living things and why. After the survey is taken, note that their own surroundings tend to their environment dictate their food selections. For instance, some people can grow up eating and enjoying insects or raw fish as delicacies—both of which may 3 – 5 be distasteful to others. This exercise illustrates the notion that both genetic • Adaptations of living things and environmental factors can influence a behavior, such as appetite. • Characteristics of plants and animals 2. Compare your facial expressions to those of chimpanzees.4 In front of a mirror, make these same faces yourself. Since we share a very recent 6 – 8 common ancestor with chimpanzees, note that our facial expressions are • Reproduction and heredity similar to theirs, although they might be used for different purposes. This • Living things and their indicates that our ancestor most likely shared this wide-range set with us environment because some behaviors, like facial expressions, are based in genetics. 9 – 12 • Ecology • Evolution and heredity play pout anger fear References: 1Sibley, D.A. The Sibley Guide to Birds. New York: Alfred A. Knopf, 2000. 2Winkler, D.W., et al. “Evolution of Nest Construction in Swallows (Hirundinidae): A Molecular Phylogenetic Perspective.” Proceedings of the National Academy of Sciences. 90 (1993): 5705-5707. 3Brown University. 2002. Evolution of Behavior. Providence. Available online: http://biomed.brown.edu/Courses/BIO48/16.Evol.Behavior.HTML. 4Parr, Lisa. 2002. Living Links. Emory University. Available online: http://www.emory.edu/LIVING_LINKS/parr.html. Explore our connectedness to other species, past and present, in the new permanent Human Evolution exhibit. Now open in the Human Body Connection. PDF9/06JFFL Understanding adaptive radiation with geese Branta canadensis (Canada Goose) Museum of Science, Boston Explore the connections Five hundred thousand years ago, migrating geese, very similar to the Canada geese we know today, landed on the recently formed islands of Hawaii.1 The geese had virtually no predators on these islands and were free to wander and reproduce in many different niches of their new habitat. Several new species of geese, including the Nene, evolved. This branching spread of new species is called adaptive radiation. They adapted differently than their parent population on the mainland of North America, where relatives of the ancestral Canada geese changed very little in behavior or appearance. The adaptive radiation illustrated by the Nene shows us that geographic separation of animal species into two or more groups can lead to substantial evolutionary changes among different subpopulations. The new environment introduces new selection pressures that favor different traits. As a consequence, geese with these different traits survive more often and leave more offspring in the next generation. Adaptive radiation generally occurs when there is a rapid change in the environment that causes differential selection for certain genetic traits within a population of organisms. Geographic isolation is a process whereby rivers, mountains, oceans, and other geographic features split apart groups of organisms, supplying the background for adaptive radiation to take place. Concepts and misconceptions CONCEPT • The rate of evolutionary changes in living things can vary dramatically depend- ing on the organism’s lifespan, environmental pressures, or the introduction of a new trait. Evolution can proceed very quickly if there is rapid reproduction and strong environmental pressures. MISCONCEPTIONS Many people mistakenly think that: • Evolutionary changes always take place over millions of years. In fact, in organisms that reproduce rapidly (like bacteria and insects) change can be seen in a very short period of time. • Appearance strictly determines relatedness. This is not true. Looks can often be deceiving. They should not be used to indicate an evolutionary relationship. Scientists use various methods of comparison to determine relatedness. Exhibit scavenger hunt Go to the Natural Mysteries exhibit, located in the Blue Wing, Lower Level, and find two Canada Geese flying high in the room. When you look at the Canada Geese, take note of the size of their wings and the shape of their feet. Now look at this drawing of the endangered Hawaiian goose called the Nene. It is much smaller than the Canada Goose, with different coloration, longer toenails, and less webbing on its feet. Recent DNA studies show how several geese are related (illustrated in the chart below).1 Draw a circle around the species of goose that is most closely connected on the chart to the Nene. This is the species that is most closely related to the Nene. Notice that although Nenes and Canada Geese look different, genetics shows us that they are actually closely related. Goose Family Tree Pick an animal and trace the line from right to left. The point where your animal Nene intersects the line of another animal is where the two share a common ancestor. Branta sandvicensis — Nene Branta canadensis — Greater Goose Branta canadensis parvipes — Lesser Goose Branta bernicla — Brant Additional activities for home or school 1. Because species on islands are geographically isolated, they are interesting places to study evolution. Research the kinds of animal life on Madagascar NOTE TO TEACHERS and Australia, islands that have separated from other land forms; and on This activity relates to the Hawaii and the Galapagos, islands created by volcanism.