Concept map

***Note*** All numbers in the yellow squares refer to relevant Massachusetts Middle School Science Technology & Engineering Life Science (MA STE MS-LS) frameworks, unless otherwise stated. For more detail, refer to the STE Frameworks document on the Resources page.

Unit Overview

During Unit 3, students will transition from studying physical systems to studying life science. They will begin by developing a model for how natural selection could act as a mechanism by which evolution could occur. They will then begin to investigate various lines of evidence that support that these processes have, and continue to occur in the natural world. Next they will investigate how human genetic material is structured, organized, and replicated, and how cell division facilitates this process. Finally they will develop a model for how scientists trace the prevalence of certain traits and features throughout many generations as a means to consider why they are, in a sense, like they are. From NGSS: The Performance Expectations in Natural Selection and Adaptations help students formulate answers to the questions: “How does genetic variation among organisms in a species affect survival and reproduction? How does the environment influence genetic traits in populations over multiple generations?” Middle school students can analyze data from the fossil record to describe evidence of the history of life on Earth and can construct explanations for similarities in organisms. They have a beginning understanding of the role of variation in natural selection and how this leads to speciation. They have a grade-appropriate understanding and use of the practices of analyzing graphical displays; using mathematical models; and gathering, reading, and communicating information. The crosscutting concept of cause and effect is central to this topic.

Unit 3 Essential Questions

• What are the limitations of our models for predicting the prevalence of traits in a generation?
• How do we use population data support the mechanism of evolution by natural selection?
• How do organisms change over time in response to changes in their environment?
• What are costs and benefits of human designed artificial selection?
• What can the fossil record tell us about changes in species over time?
• Does comparing anatomical structures accurately tell us about evolutionary relationships?

Lesson Descriptions

Lesson 3.1-Flight of the loop bird

Students will model the reproductive success of the loop birds as a means to examine how different features can lead to differences in biological fitness and subsequent reproductive success for the birds.

Lesson 3.2-Natural selection

Students will generate symbolic storyboards involving correct and incorrect models of natural selection so that they can generate an accurate model for how populations change over time.

Lesson 3.3-Becoming whales

Students will compare segments of whale DNA with those of other animals in order to infer how closely the different species are related in evolutionary terms.

Lesson 3.4-Genomes, chromosomes and DNA

Students will follow a webquest in order to learn about the different levels of organization for genetic material.

Lesson 3.5-Mr. Potato Head genetics

Students will identify patterns of inheritance for several traits with a familiar toy model.

Lesson 3.6-Mendel's peas

Students will learn about the role of probability in determining the frequencies of traits through the generations based upon Gregor Mendel's experiments.

Lesson 3.7-The royal disease

Students will learn how to design and interpret a pedigree chart in order to deduce whether inherited traits are dominant or recessive.

Unit Project-Flight of the loop bird lab report

Using a graphic organizer (the graph choice chart), students will identify evidence for changes in the loop bird population and develop a justification for why this occurred.