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Grade 8 - Unit 5 - Natural Selection

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Grade 8 - Unit 5 - Natural Selection Unit Focus Through the examination of several natural phenomena related to the evolution of adaptation in organisms, students will craft evidence-based explanations for traits that enable organisms to survive in their environment. Students will engage in a variety of simulations and examine case studies as they uncover the principles of natural selection that result in large variety of differences within and between species. As a foundation to this study, students will learn the basics about the genetic code and how sexual reproduction and genetic mutation give rise to the variations that are crucial for the success of populations. Stage 1: Desired Results - Key Understandings Standard(s) Transfer Next Generation Science T1 Communicate effectively based on purpose, task, and audience to promote collective understanding and/or Middle School Life Science: 6 - 8 recommend actions. T2 Make observations and ask questions to define a problem based on prior knowledge and curiosity that stimulates Use argument based on empirical evidence and further exploration, analysis, and discovery. scientific reasoning to support an explanation for how characteristic animal behaviors and Meaning specialized plant structures affect the probability of successful reproduction of animals and plants Understanding(s) Essential Question(s) respectively. MS-LS1-4 Construct an explanation based on evidence that U1 Evolution results primarily from natural selection: Q1 Why do organisms seem to be so adapted to the places describes how genetic variations of traits in a genetic variation of individuals in a species, competition that they live? What happens when their environment population increase some individuals' probability for resources, and proliferation of organisms better able to changes? of surviving and reproducing in a specific survive and reproduce. Q2 How does the process of natural selection explain the environment. MS-LS4-4 U2 Natural selection leads to organisms with adaptations evolution of a species over time? (anatomical, behavioral, and physiological) that are well Q3 How does sexual reproduction lead to variation Next Generation Science Standards (DCI) suited to survival and reproduction in a particular between parents and offspring? Science: 8 environment. Q4 What impact can mutations have on living things? U3 Species can change over time in response to changes in environmental conditions through natural selection Animals engage in characteristic behaviors that acting over generations. Traits that support successful increase the odds of reproduction. LS1.6.B1 survival and reproduction in the new environment become Organisms reproduce, either sexually or asexually, more common. and transfer their genetic information to their U4 The distribution of traits in a population, as well as offspring. LS1.6.B2 species expansion, emergence or extinction, can change Genes are located in the chromosomes of cells, when conditions change. with each chromosome pair containing two U5 Organisms reproduce, either sexually or asexually, and variants of each of many distinct genes. Each transfer their genetic information to their offspring. Madison Public Schools | July 2019 1 Stage 1: Desired Results - Key Understandings distinct gene chiefly controls the production of U6 The variation and distribution of traits in a population specific proteins, which in turn affects the traits of depend on genetic and environmental factors. the individual. Changes (mutations) to genes can U7 Organisms inherit chromosomes from their parents result in changes to proteins, which can affect the containing genes that code for different proteins which structures and functions of the organism and affect an individual’s traits. thereby change traits. LS3.6.A1 U8 Genetic information can be altered because of Variations of inherited traits between parent and mutations, which may result in beneficial, negative, or no offspring arise from genetic differences that result change to the proteins and traits of an organism. from the subset of chromosomes (and therefore U9 Natural selection occurs only if there is variation in the genes) inherited. LS3.6.A2 genes and associated traits between individuals in a In addition to variations that arise from sexual population. Traits that positively affect survival can reproduction, genetic information can be altered become more common in a population. because of mutations. Though rare, mutations may result in changes to the structure and function of Acquisition of Knowledge and Skill proteins. Some changes are beneficial, others harmful, and some neutral to the organism. Knowledge Skill(s) LS3.6.B2 Natural selection leads to the predominance of K1 Natural selection is the process that explains how S1 Applying the principles of natural selection to explain certain traits in a population, and the suppression of certain traits in populations arose. how adaptations in organisms evolve. others. LS4.6.B1 K2 Charles Darwin's observations of the slight variations S2 Apply knowledge to develop a prediction or a claim Adaptation by natural selection acting over in organisms along the South American coast and the that is justified by evidence. generations is one important process by which Galapagos Islands is an example of how scientific S3 Analyzing a case study and synthesizing concepts to species change over time in response to changes in observations and inferences can explain natural develop a scientifically-based explanation. environmental conditions. Traits that support phenomena. successful survival and reproduction in the new K3 Favorable variations are those traits that help an environment become more common; those that do organism to survive and reproduce, thereby passing on the not become less common. Thus, the distribution of genes for this trait to their offspring. traits in a population changes. LS4.6.C1 K4 When an organism has a favorable variation/trait that makes them more likely to survive to reproduce and pass Student Growth and Development 21st Century on the genes for this trait, it is likely that the trait will Capacities Matrix become more common in a population. Critical Thinking K5 When environments change, species adapt, flee, or die. Analyzing: Students will be able to examine K6 When environments change, sometimes a trait information/data/evidence to make inferences and becomes more favorable and thereby becomes more identify possible underlying assumptions, patterns, common in the population over time. and relationships. MM.1.2 K7 Organisms cannot "will" themselves to change, rather, Synthesizing: Students will be able to thoughtfully the variations in traits that they possess make them more combine information/data/evidence, concepts, or less likely to survive, reproduce, and pass the genes for texts, and disciplines to draw conclusions, create their variations onto their offspring. Madison Public Schools | July 2019 2 Stage 1: Desired Results - Key Understandings solutions, and/or verify generalizations for a given K8 Evolution occurs in species over a very long period of purpose. MM.1.3 time and can result in the formation of new species. K9 Genetic variation can result from sexual reproduction and mutations. K10 Sexual reproduction is primarily responsible for variation in populations because it scrambles the genes in a person and then combines these genes with another. K11 Genes are located on chromosomes in cells. K12 The genetic code of all organisms is comprised of A, T, C, and G bases in a particular sequence. If this sequence is changed due to a mutation, it can change the traits of an organism. K13 Genetic mutations can result in changes to the proteins produced thereby changing traits. K14 Genetic mutations can have a negative, positive, or neutral effect an on organisms traits (physical and behavioral). K15 Natural Selection Vocabulary: meiosis, sexual reproduction, genes, chromosomes, natural selection, evolution, genetic diversity, population, variations, fitness of genes, adaptation (Physical/Behavioral), mutation, genetic code Madison Public Schools | July 2019 3 .
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