One Stop Shop For Educator The following instructional plan is part of a GaDOE collection of Unit Frameworks, Performance Tasks, examples of Student Work, and Teacher Commentary. Many more GaDOE approved instructional plans are available by using the Search Standards feature located on GeorgiaStandards.Org. HOW DO WE KNOW? Content: S7L5. Students will examine the evolution of living organisms through inherited characteristics that promote survival of organisms and the survival of successive generations of their offspring. a. Explain that physical characteristics of organisms have changed over successive generations (e.g. Darwin s finches and peppered moths of Manchester). c. Trace evidence that the fossil record found in sedimentary rock provides evidence for the long history of changing life forms. Habits of Mind: S7CS1. Students will explore the importance of curiosity, honesty, openness, and skepticism in science and will exhibit these traits in their own efforts to understand how the world works. a. Understand the importance of and keep honest, clear, and accurate records in science. b. Understand that hypotheses can be valuable, even if they turn out not to be completely accurate. S7CS3. Students will have the computation and estimation skills necessary for analyzing data and following scientific explanations. d. Draw conclusions based on analyzed data. S7CS4. Students will use tools and instruments for observing, measuring, and manipulation equipment and materials in scientific activities. a. Use appropriate technology to store and retrieve scientific information in topical, alphabetical, numerical, and keyword files, and create simple files. JULY 2008 Page 1 of 4
One Stop Shop For Educators S7CS5. Students will use the ideas of system, model, change, and scale in exploring scientific and technological matters. b. Understand that different models (such as physical replicas, pictures, and analogies) can be used to represent the same thing. S7CS6. Students will communicate scientific ideas and activities clearly. c. Organize scientific information using appropriate simple tables, charts, and graphs, and identify relationships they reveal. S7CS7. Students will question scientific claims and arguments effectively. a. Question claims based on vague attributions (such as Leading doctors say ) or on statements made by people outside the area of their particular expertise. b. Identify the flaws of reasoning that are based on poorly designed research. (i.e., facts intermingled with opinion, conclusions based on insufficient evidence.) c. Question the value of arguments based on small samples of data, biased samples, or samples for which there is no control. d. Recognize that there may be more than one way to interpret a given set of findings. Nature of Science: S7CS8. Students will investigate the characteristics of scientific knowledge and how that knowledge is achieved. c. As prevailing theories are challenged by new information, scientific knowledge may change. S7CS9. Students will investigate the features of the process of scientific inquiry. a. Investigations are conducted for different reasons, which include exploring new phenomena, confirming previous results, testing how well a theory predicts, and comparing competing theories. b. Scientific investigations usually involve collecting evidence, reasoning, devising hypotheses, and formulating explanations to make sense of collected data. d. Scientists often collaborate to design research. To prevent this bias, scientists conduct independent studies of the same questions. e. Accurate record keeping, data sharing, and replication of results are essential for maintaining an investigator s credibility with other scientists and society. Scientists use technology and mathematics to enhance the process of scientific inquiry. JULY 2008 Page 2 of 4
One Stop Shop For Educators Enduring Understandings: Physical characteristics of populations of organisms change over time due to changing conditions. Fossils provide evidence for change. Essential Question: How does a paleontologist use observations of fossils to make inferences about ancient living organisms. ADMINISTRATION PROCEDURES Outcome / Performance Expectations: General Teacher Instructions: The students will utilize reading comprehension strategies such as comparing and contrasting and graphic organizers to understand how we come to know about the evolutionary past. Look to the following essential question to drive the task(s): How does a paleontologist use observations of fossils to make inferences about ancient living organisms? Materials Needed: 1. Ask Jeeves article 2. Ask Jeeves graphic organizer Safety Precautions: Task with Student Directions: None I. Teaching/Learning Task: Ask Jeeves Purpose: To apply reading and comprehension skills to ascertain an understanding of how paleontologists base claims with evidence JULY 2008 Page 3 of 4
One Stop Shop For Educators Materials: One copy of the Ask Jeeves article for each student, one Ask Jeeves graphic organizer for each student. 1. Dispense the graphic organizer to students. 2. Give the directive that they will be comparing and contrasting a paleontologist with a criminal investigator. 3. As the students read the first page of the Ask Jeeves article, they will need to fill out section one of the graphic organizer. 4. As the students read the second page of the Ask Jeeves article, they will need to fill out the second section of the graphic organizer. II. Summarizing Activity: Ticket Out the Door Purpose: To challenge students to synthesize the essential concepts learned Materials: A ticket out the door (scrap paper will work) 1. Give students a small slip of paper. 2. Inform students that this is their ticket-out-the-door. 3. Ask the students to respond to the prompt, Is what we know about extinct organisms based on our beliefs? JULY 2008 Page 4 of 4
Back Dear Jeeves How do scientists know? I mean how do they know about living things that existed long ago, like dinosaurs? How do they know what they looked like? How do they know what they ate? How do they know how fast they grew? It seems a little far fetched to me, because no humans were roaming the planet making observations, taking pictures, or making video recordings at this time. Are scientists pulling our legs about what they claim to know so much about extinct organisms? --Cynthia Cynthia, great questions! Many others like you have these similar questions. Let s make an analogy. Let s relate the job of a paleontologist (someone who studies extinct life forms) to a criminal investigator who solves murder mysteries. Both individuals are faced with a mystery to solve. For the criminal investigator, the mystery is Who committed the murder? For the paleontologist, the mystery is What was the nature of this extinct organism? The challenge exists, because the answers lie in the events of the past. How do they come to understand an event that happened in the past? How can they answer their questions? There is no room for mistakes for either the paleontologist or the criminal investigator. They are both called to adhere to high ethical standards. For the paleontologist, his/her duty is to science, a discipline that seeks to understand the natural world. His/her reputation is on the line if false claims are made. For the criminal investigator, his/her duty is to a democratic society that promotes justice for all. A man or women s life may be on the line if a conviction is made. Neither wants to fail his or her respective disciplines. However, there are some crooked criminal investigators and some scientists who do poor science. Shame on them! Neither the paleontologist or the criminal investigator directly witnessed the event under investigation. So, there are no direct observations to make. However, indirect observations (evidence collected after the fact) can be made. The criminal investigator can go to the crime scene to collect/observe the body of the deceased, blood samples, hair samples, the murder weapon, a note left by the perpetrator, and statements made by witnesses. The criminal investigator uses these indirect observations to recreate, as accurately as possible, what occurred at the crime scene. Likewise, the paleontologist can make indirect observations. They can collect fossils during fossil digs and date the sediment from which the fossils were studied. Based on this indirect evidence, a picture of the past can be recreated. Let s summarize. How are paleontologists and criminal investigators similar?
Example One: How do we know what the extinct organisms looked like? This image shows the skeletal remains of an extinct tetrapod (one of the first living things to walk on land). Notice how the fossil has characteristics for living successfully in water and on land, limbs for walking and a fin like tail for swimming. Paleontologists use the skeletal remains of the fossil as the basis for reconstructing a picture of the organism (see the images below). These images may change as more tetrapod fossils are collected. Yes, science can change. Will our reproductions of this tetrapod greatly change with new information? Example Two: How do we know what extinct organisms ate? Almost always, an organism s teeth gives it away. A carnivore has many sharp pointy teeth called canines or a combination of canines and sharp, pointy molars. An herbivore has flat molars for grinding vegetation, and incisors for cutting (incisors are the front teeth of a rabbit). An omnivore has a combination of incisors, canines, and molars. What inference can you make about the diet of this tetrapod based on its teeth? If you chose carnivore you are correct. This tetrapod has many canine teeth. Scientists have also observed that these teeth are very similar to the teeth of current day fish. Example Three: How fast did dinosaurs grow? Scientist Kristi Curry-Rogers can answer this question. She is an expert on dinosaur bones. She knows that the blood vessel patterns made in bones can tell us how fast the bones developed. Orderly patterns of blood vessels suggest that the bones developed relatively slowly. Irregular blood vessels patterns suggest that the bones developed very quickly. Dinosaur bones show irregular blood vessel patterns. After comparing dinosaur bones with current day reptilian bones, Kristi estimates that dinosaurs developed to maturity in 10-12 years. Kristi s estimate may be slightly off, but it s the best estimate we have based on the evidence that exists. Future studies of dinosaur bones may develop our understanding of dinosaurs and growth rates. Dr. Curry-Rogers collects dinosaur bone slices and views them under a microscope. Images were copied from: http://www.pbs.org/
Back Graphic Organizer Student name: I. Comparing and contrasting a paleontologist with a criminal investigator. Paleontologists Only Both Paleontologists and Criminal Investigators Criminal Investigators Only II. Basing Claims on Evidence: 1. Scientists base claims on evidence. In other words, they draw their conclusions from the observations that are made. Based on the reading, fill in the chart below, showing the claims that paleontologists make, and the evidence or observations that support these claims. Claim Made Evidence