Biology, Quarter 4, Unit 4.1. Evolution. Overview

Transcription

1 Evolution Overview Number of instructional days: 21 (1 day = 50 minutes) Content to be learned Distinguish between microevolution and macroevolution. Explain how macroevolution accounts for the speciation, extinction, and evolution of varied structures. Given information about organisms (extinct or living), cite evidence to explain the frequency of inherited characteristics of organisms in a population Cite evidence of how natural selection and its evolutionary consequences provide a scientific explanation for the diversity and unity of past and present lifeforms on earth. Relate how geologic time is determined using various dating methods. Analyze samples of rock to determine the relative age of the rock structure. Illustrate that, when an environment changes, the survival advantage/disadvantage of some characteristics may change. Recognize patterns in molecular and fossil evidence to provide a scientific explanation for natural selection and its evolutionary consequences. Provide supporting geologic/geographic evidence that supports the validity of the theory of plate tectonics. Use given data and advances in technology to explain how scientific knowledge regarding plate tectonics has changed over time. Science processes to be integrated Make predictions based on evidence. Ask questions and formulate hypothesis. Collect, represent, analyze and interpret data. Use evidence to draw conclusions. Interpret divergent ideas as they relate to varied attitudes and dispositions. Apply evidence of scientific theories. Examine patterns of change. Identify relationships between form and function in the natural world. Communicate understanding and ideas. 39

2 Evolution (21 days) Essential questions How do microevolution and macroevolution compare and how do they account for the diversity of specific inherited characteristics within a population? How does natural selection explain the diversity and unity of past and present life forms on earth? What evidence exists for the scientific explanations for natural selection and its evolutionary consequences? What evidence exists for the theory of evolution? How does the environment influence the survival advantage/disadvantage of certain characteristics? How do scientists determine geologic time and the relative ages of rock structures? What geologic/geographic evidence is there for the theory of plate tectonics and how has this evidence changed over time? Written Curriculum Grade-Span Expectations LS3 - Groups of organisms show evidence of change over time (structures, behaviors, and biochemistry). LS3 (9-11) INQ FAF+POC -8 Given information about living or extinct organisms, cite evidence to explain the frequency of inherited characteristics of organisms in a population, OR explain the evolution of varied structures (with defined functions) that affected the organisms survival in a specific environment (e.g., giraffe, wind pollination of flowers). LS3 (9-11) -8 Students demonstrate an understanding of Natural Selection/ evolution by 8b distinguish between microevolution (on small scale within a single population e.g., change in gene frequency within a population) and macroevolution (on a scale that transcends boundaries of a single species e.g., diversity of all beetle species within the order of insects) and explain how macroevolution accounts for speciation and extinction. LS3 (9-11) INQ POC-7 Given a scenario, provide evidence that demonstrates how sexual reproduction results in a great variety of possible gene combinations and contributes to natural selection (e.g., Darwin s finches, isolation of a species, Tay Sach s disease). LS3 (9-11) -7 Students demonstrate an understanding of Natural Selection/ evolution by 7c citing evidence of how natural selection and its evolutionary consequences provide a scientific explanation for the diversity and unity of past and present life forms on Earth. (e.g. Galapagos Islands, Hawaiian Islands, Australia, geographic isolation, adaptive radiation). 40

3 Evolution (21 days) ESS1 - The earth and earth materials as we know them today have developed over long periods of time, through continual change processes. ESS1 (9-11) INQ+POC+ MAS 4 Relate how geologic time is determined using various dating methods (e.g. radioactive decay, rock sequences, fossil records). ESS1 (9-11) 4 Students demonstrate an understanding of processes and change over time by 4bb analyzing samples of rock to determine the relative age of the rock structure. LS3 - Groups of organisms show evidence of change over time (structures, behaviors, and biochemistry). LS3 (9-11) INQ FAF+POC -8 Given information about living or extinct organisms, cite evidence to explain the frequency of inherited characteristics of organisms in a population, OR explain the evolution of varied structures (with defined functions) that affected the organisms survival in a specific environment (e.g., giraffe, wind pollination of flowers). LS3 (9-11) -8 Students demonstrate an understanding of Natural Selection/ evolution by 8a illustrating that when an environment changes, the survival advantage /disadvantage of some characteristics may change. LS3 (9-11) -8 Students demonstrate an understanding of Natural Selection/ evolution by 8c recognizing patterns in molecular and fossil evidence, to provide a scientific explanation for Natural Selection and its evolutionary consequences (e.g. survival, adaptation). ESS1 - The earth and earth materials as we know them today have developed over long periods of time, through continual change processes. ESS1 (9-11) NOS 2 Trace the development of the theory of plate tectonics or provide supporting geologic/geographic evidence that supports the validity of the theory of plate tectonics. ESS1 (9-11) 2 Students demonstrate an understanding of processes and change over time within earth systems by 2a using given data (diagrams, charts, narratives, etc.) and advances in technology to explain how scientific knowledge regarding plate tectonics has changed over time. 41

4 Evolution (21 days) Clarifying the Standards Prior Learning In grades K 2, students demonstrated an understanding of processes and change over time within earth s systems by observing and recording seasonal and weather changes throughout the school year. In grades 3 4, students observed local landforms and how wind, water, or ice have shaped and reshaped the earth. Students used models to simulate the effects of how wind and water shaped and reshaped the land. Students identified sudden and gradual changes, such as floods and erosion, that alter the earth s surface. In grades 5 6, students were first exposed to the concept of evolution. They cited examples supporting the concept that certain traits of organisms may provide a survival advantage in a specific environment and therefore, an increased likelihood to produce offspring. Students demonstrated an understanding of natural selection/evolution by explaining how a population s or species traits affect their ability to survive over time. They researched or reported on possible causes for the extinction of an animal or plant. They explained how fossil evidence can be used to understand the history of life on earth. In grades 7 8, they demonstrated their understanding of this concept by explaining that genetic variations/traits of organisms are passed on through reproduction and random genetic changes. They gathered evidence that demonstrates evolutionary relationships among organisms (e.g.. similarities in body structure and early development). They differentiated between acquired and inherited characteristics, giving examples of each. They also explained how natural selection leads to evolution. They learned how scientists understanding about the way species originate or become extinct has changed over time. Current Learning The instructional level for this unit is both developmental and reinforcement. Students have been exposed to the study of natural selection and the theory of evolution. Instruction about these concepts should be at the reinforcement level. The distinction between microevolution and macroevolution should be taught at the developmental level as well as the examination of scientific evidence for evolution, natural selection, and the plate tectonic theory. Rock analysis to determine relative age should also be taught at the developmental level of instruction. Given information about organisms, extinct or living, students will cite evidence to explain the frequency of inherited characteristics of organisms in a population. This will help students to understand the basis of microevolution. One way to accomplish this is through the use of Hardy-Weinberg Equilibrium Theory. There are many short investigations that demonstrate changes in allele frequencies from one generation to the next. Next, students will explain how macroevolution accounts for speciation, extinction, and the evolution of varied structures. Students will distinguish between microevolution and macroevolution. Students will cite evidence of how natural selection and its evolutionary consequences provide a scientific explanation for the diversity and unity of past and present lifeforms on earth. Through various activities, students will learn what natural selection is and how it could account for adaptations in species. They should demonstrate an understanding of natural selection/evolution by illustrating that, when an environment changes, the survival advantage/disadvantage of some characteristics may change. Again, there are many activities that could be used to demonstrate the effect of changes in the environment (i.e., color of surrounding habitat and appropriate camouflage) on the survival rate of different phenotypes. 42

5 Evolution (21 days) In addition to the study of natural selection, students will explore geologic time and the evidence that exists for both the theory of evolution and plate tectonics. For example, the fossil record provides evidence for both evolution and plate tectonics. Comparison of fossils will show change in species over time and comparison of fossil evidence from different continents (i.e., Africa and South America) shows that earth s plates are in continuous motion. Another way to demonstrate evidence for plate movement is through examination of a hot-spot island chain. Students could predict where the next island will form and/or the direction of plate movement. During this study, they should relate how geologic time is determined using various dating methods by analyzing samples of rock to determine the relative age of the rock structure. They should also recognize patterns in molecular and fossil evidence, to provide a scientific explanation for natural selection and its evolutionary consequences. Students should demonstrate an understanding of processes and change over time within earth systems by using given data and advances in technology to explain how scientific knowledge regarding plate tectonics has changed over time. Many teachers will also use this opportunity to introduce other types of evidence for evolution, such as vestigial and homologous structures. Students will predict, question, and hypothesize about the potential outcomes of various evolutionary scenarios. For example, students might analyze an environmental change and predict the potential evolutionary outcome (i.e., phenotypic change) due to this event. Students should collect, represent, analyze, and interpret data through the use of various activities that utilize the Hardy Weinberg equation and are based on an understanding of Hardy Weinberg equilibrium. Based on the results of this analysis, they should use evidence to conclude whether a population is, in fact, evolving (i.e., microevolution is occurring). Embedded throughout this unit, students will interpret divergent ideas as they relate to varied attitudes and dispositions towards the theory of evolution. Students might be given the opportunity to present their own ideas about this topic. They should be made aware of the history of scientific theories of evolution and plate tectonics, through a brief study of the key scientists that contributed to these theories. Students should learn about evolutionary patterns of change and the relationship of these changes to form and function in the natural world. An example might be evolutionary history of a particular type of organism (i.e., horses or plants) and how changes relate to form and function that suit different environments. As the unit progresses, students will be able to communicate understanding and ideas about these complex topics. Although students have a basic knowledge of natural selection and evolution from the middle grades, they have not investigated these ideas in detail. For example, they understood that characteristics change over time but they now can apply their knowledge of genetics to support the how and why of these changes. The previous unit on genetics is essential to their understanding of microevolution, which is a new concept at this grade level. In addition to microevolution, at this grade level, students explore macroevolution and learn about the history of this scientific knowledge. They investigate evidence from many sources (fossils, plate tectonics, etc.) and utilize this evidence to support claims about the history of life on earth. 43

6 Evolution (21 days) Future Learning In the next unit of study, Classification of Life, they will use a great deal of this information. In order for students to classify organisms, they need to understand the evolutionary history and relatedness of various species. The next unit is really an extension of this unit, in that they apply knowledge in order to construct or use models (such as phylogenetic trees and cladograms) that represent the relatedness and grouping of organisms. Additional Findings History should not be overlooked. Learning about Darwin and what led him to the concept of evolution illustrates the interacting roles of evidence and theory in scientific inquiry. Moreover, the concept of evolution provided a framework for organizing new as well as old biological knowledge into a coherent picture of life forms. (Benchmarks for Science Literacy, p. 124) Opposition has come and continues to come from people whose interpretation of religious writings conflicts with the story of evolution. Schools need not avoid the issue altogether. Perhaps science courses can acknowledge the disagreement and concentrate on frankly presenting the scientific view. Even if students eventually choose not to believe the scientific story, they should be well informed about what the story is. (Benchmarks, p. 124) Some people interpret these ideas to be in inconsistent with their own beliefs about the diversity of life on earth. These ideas, nonetheless, are an important part of modern science and science literacy requires at least knowing what they are, whether students believe them to be true or not. (Atlas of Science Literacy Vol. 1, p. 80) Students appear to show confusion between an individual s adaptation during its lifetime and inherited changes in a population over time. They tend to believe in the Lamarckian theory of inheritance of acquired characteristics. In one study, only 18% of students, even after studying A level biology, could correctly apply a process of selection to evolutionary change. Most gave the Lamarckian interpretation that individuals can adapt to change in the environment if they need to, and that these adaptations are inherited. One researcher considers that preexisting Lamarckian ideas can block the understanding of a Darwinian explanation. (Making Sense of Secondary Science, p. 53). 44

7 Biology, Quarter 4, Unit 4.2 Classification of Life Overview Number of instructional days: 6 (1 day = 50 minutes) Content to be learned Demonstrate an understanding of how organisms are organized into a hierarchy of groups and subgroups based on evolutionary relationships. Use data or models to analyze how organisms are organized into a hierarchy of groups and subgroups based on evolutionary relationships. Explain how evidence from technological advances supports or refutes the degree of genetic relationships among groups of organisms. Use given data and advances in technology to explain how our understanding of genetic variation has developed over time. Essential questions How can genetic and evolutionary relationships be used to classify organisms? How can data and/or models be used to analyze how organisms are organized into a hierarchy of groups and subgroups based on evolutionary relationships? Science processes to be integrated Represent, analyze, and interpret data. Use evidence to draw conclusions about evolutionary change in the natural world. Communicate understanding and ideas. Identify patterns of change. How has evidence from technological advances supported or refuted our understanding of the degree of genetic relationships among organisms? How has our understanding of genetic variation developed over time? 45

8 Biology, Quarter 4, Unit 4.2 Classification of Life (21 days) Written Curriculum Grade-Span Expectations LS3 - Groups of organisms show evidence of change over time (structures, behaviors, and biochemistry). LS3 (9-11) INQ FAF+POC -8 Given information about living or extinct organisms, cite evidence to explain the frequency of inherited characteristics of organisms in a population, OR explain the evolution of varied structures (with defined functions) that affected the organisms survival in a specific environment (e.g., giraffe, wind pollination of flowers). LS3 (9-11) -8 Students demonstrate an understanding of classification of organisms by 8d using data or models (charts, diagrams, table, narratives etc.) to analyze how organisms are organized into a hierarchy of groups and subgroups based on evolutionary relationships. (e.g. creating a taxonomic key to organize a given set of examples). LS3 (9-11) NOS -6 Explain how evidence from technological advances supports or refutes the genetic relationships among groups of organisms (e.g., DNA analysis, protein analysis. LS3 (9-11)-6 Students will demonstrate their understanding of the degree of genetic relationships among organisms by 6a using given data (diagrams, charts, narratives, etc.) and advances in technology to explain how our understanding of genetic variation has developed over time. Clarifying the Standards Prior Learning In grades K 4, students sorted, classified, and compared different things using physical characteristics. This included distinguishing living from nonliving. In the early grades, they focused on observing, recording data, and analyzing data about external features. They were expected to cite evidence to distinguish living from nonliving, and to draw conclusions, explaining why organisms are/are not grouped together. In grades 5 6, students understood that organisms have features that help them to survive in their habitat/environment. They identified that certain features support life in certain habitats/environments. They used a model, classification system, or dichotomous key to illustrate, compare, or interpret possible relationships among groups of organisms. They should have been able to state the value of, or reasons for, classification systems. Additionally, they followed a taxonomic key to identify a given organism. At this 46

9 Biology, Quarter 4, Unit 4.2 Classification of Life (21 days) level, they should have been able to sort organisms into groups based on both internal and external structures. In grades 7 8, students explained how species with similar evolutionary histories/characteristics are classified more closely together with some organisms more than others (e.g., a fish is more closely related to a human than it is to a sea jelly). At this stage they should have also recognized the classification system used in modern biology. Current Learning The instructional level for this unit is both developmental and reinforcement. It is developmental in that students have not previously analyzed or constructed these models in order to determine degree of relatedness among organisms. They have also never analyzed organisms based on molecular evidence. It is reinforcement in that they have already classified organisms based on outward characteristics. They have also been exposed to the modern system of classification. In this unit of study, students will demonstrate an understanding of how organisms are organized into a hierarchy of groups and subgroups based on evolutionary relationships. Additionally, they will use data or models to analyze evolutionary relationships among organisms. Students should be able to explain how evidence from technological advances supports or refutes the degree of genetic relationships among organisms. Finally, they will use given data and advances in technology to explain how our understanding of genetic variation has developed over time. The processes that students will need in order to master the content in this unit of study are representing, analyzing, and interpreting data regarding the classification of organisms. They will use evidence to draw conclusions about evolutionary change in the natural world. They will then communicate understanding and ideas about the classification of life. When students are learning the content/processes, they will be sorting objects and/or living things into groups and subgroups based on relationships. This will introduce the importance of classification. For students to understand how technological advances have changed our understanding of genetic and evolutionary relationships, it is useful for them to be exposed to classical grouping based on physical characteristics as well as current models based on molecular evidence. They should understand that classification systems have changed over time with new advances in technology and that traditional groupings are under revision based on this evidence. Next, the concept of grouping organisms based on evolutionary relationships must be addressed. This could be accomplished through the use of character tables and cladograms, whether students create these or analyze them. By the end of this unit, students should be able to analyze given data and/or models in order to determine the degree of relatedness amongst organisms. They should also understand the importance of a universal classification system for living things. The learning that must be accomplished in this unit is different from previous learning because, although students have grouped/classified living things before, this is the first time that they are expected to analyze the degree of relatedness. In middle school, they should have already learned the classification system used in modern biology. Now they understand how and why organisms are placed into these groups and subgroups. 47

10 Biology, Quarter 4, Unit 4.2 Classification of Life (21 days) Future Learning If students have not yet taken a course in chemistry, this unit will help them to understand how nonliving matter is grouped based on chemical and physical properties. It will also help them to understand the importance of the organized system for grouping elements using the Periodic Table of Elements. Additional Findings At the high school level, to deepen student understanding of technology, students now should be helped to develop a deeper understanding of the relationships linking technology and science. That can come from reflection on project experiences and from a study of the history of science and technology. (Benchmarks for Science Literacy, p. 47). A researcher found that English twelve-year-olds encountered difficulties in classifying organisms into taxonomic categories, more so with plants than with animals. Children of all ages focused on more obvious features such as number of limbs or habitat, rather than on more fundamental differences such as physiology, when classifying living things. Many students relied on every day, rather than on the taxonomic, use of class names such that jellyfish and starfish were classified as fish, and turtles with amphibious habits were classified as amphibians. (Making Sense of Secondary Science, pp ). 48