- Identify and explain a scientific theory
- Demonstrate an understanding of the theory of evolution.
- Communicate an explanation about the theory of evolution using evidence from multiple sources.
- Disciplinary Core Idea: LS4.A Evidence of Common Ancestry and Diversity
- Science and Engineering Practice: Constructing Explanations and Designing Solutions
- Crosscutting Concepts: Scientific Knowledge Assumes an Order and Consistency in Natural Systems
- Scientific knowledge is based on the assumption that natural laws operate today as they did in the past and will continue to do so in the future.
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Common practice in science is to test and improve or discard standing theories. The geocentric universe theory is an example of a theory that was repeatedly tested and subsequently discarded. It was first theorized by Greek astronomers that Earth was the center of the universe. Over time, astronomers improved their methods of observation and measurement. Using a telescope, Galileo noted that the Geocentric model could not explain the phases of Venus and Mercury or how four moons were revolving around Jupiter. Kepler used evidence from astronomer Tycho Brahe to determine that the planets moved in an elliptical course with the sun at one focus of the ellipse, not Earth. As Newton developed his laws of motion to describe the behavior of celestial objects, it was clear that the solar system did not follow a geocentric model. Sufficient evidence led the geocentric universe theory to be incorrect.
In everyday use, the term theory is regarded as a guess or hunch. In science, theories are true as far as science can establish. Theories are often built on multiple ideas with complex relationships. Theories explain some aspects of the natural world based on observations and evidence. Current theories apply to gravity, the big bang, Kepler’s laws of planetary motion, and evolution.
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For each group of/individual students:
- Ask students to fold a piece of paper into two columns and label one as “Applies to scientific theories” and the other as “Does not apply to scientific theories.” Write the following statements on the board. Guide students to sort the statements into the two columns.
- A theory never changes
- Theories are guesses scientists haves
- Theories can include opinions or personal beliefs
- Theories can be improved or modified
- There is no hierarchal relationship between theories and laws
- Theories include observations
- Theories are incomplete ideas scientists have
- A scientific law has been proven while a theory has not
- A theory is built upon one or more hypotheses, and upon evidence
|Applies to Scientific Theories||Does Not Apply to Scientific Theories|
|d) Theories can be improved or modified||a) A theory never changes|
|e) There is no hierarchal relationship between theories and laws||b) Theories are guesses scientists have|
|f) Theories include observations||c) Theories can include opinions or personal beliefs|
|i) A theory is built upon one or more hypotheses, and upon evidence||g) Theories are incomplete ideas scientists have|
| ||h) A scientific law has been proven while a theory has not|
- After five minutes of sorting, ask students to review their columns and develop a list of requirements for something to be considered a theory.
- Ask students to compare their lists and requirements with a partner. Were their lists the same or different? Were any of the statements more difficult to sort than others? Do they have a common list of requirements for something to be considered a theory?
- Guide students to identify the two key ideas in Darwin’s theory of evolution as they watch the video Introduction to Charles Darwin's Theory of Evolution (00:54). It is suggested you play the video once and then view it a second time, asking students to identify the two key ideas. Students should identify: 1) all modern species evolved from earlier forms of life, and 2) species have changed in order to adapt to their environments through a process called natural selection.
- Ask students to return to their list of requirements. Clarify to students that theories are often built on multiple ideas with complex relationships. Theories explain some aspect of the natural world based on observations and evidence.
- Explain that students will read articles to investigate why the theory of evolution is a theory and what evidence exists to support it.
- Assign students articles from the list below, and ask them to number the paragraphs in their articles. This helps pace students as they read and enables them to quickly reference parts of the article.
- Guide students to read each paragraph. Explain that after each paragraph, they should do the following:
- Summarize the main idea from a text paragraph.
- Construct a question that sums up the paragraph.
- Clarify any confusing content in the paragraph. This might require looking up key words.
- After reading, provide students with an opportunity to synthesize the text as a whole. Students should consider how the information read relates to either or both of the two key ideas of the theory of evolution: 1) all modern species evolved from earlier forms of life, and 2) species have changed in order to adapt to their environments in a process called natural selection.
- Direct students to prepare a thirty second-elevator pitch to explain whether their article supported one or both theories. Alternatively, students can read another article and compare and contrast the key ideas regarding the theory of evolution.
- Explain to students that effectively displaying information and data is a critical part of communicating science. The graphical representation of ideas has become part of our world and is a powerful way to convey information.
- Guide students to research a specific area of evolutionary evidence and create an infographic to summarize their topic. Some examples might include: fossil records, comparative anatomy, biochemical reactions, genetics, evolutionary medicine, and adaptations. Teacher note: These types of graphics can be created using many different software packages, such as PowerPoint or the free OpenOffice equivalent. Vector graphics programs, such as Inkscape (free) and Xara, can make this process easier. For the especially computer savvy, flash animations can be created.
- Students can use the Research Notes Graphic Organizer to record their information as they review their sources.
- Share with students that many people believe scientific knowledge is absolute and never changes. This is a misconception. Science is a process for producing knowledge that depends on making careful observations of phenomena and on inventing theories to make sense of those observations. Change in knowledge is expected, because new observations often challenge prevailing theories. No matter how well one theory explains a set of observations, it is possible that another theory may fit just as well or better. A common practice in science is to test and improve or discard standing theories.
- Guide students to write a one-page essay debunking the belief that scientific knowledge is absolute and static. Explain that students should use information they gathered from their articles as well as their understanding of theories as support. Additionally or alternatively, students can use evidence drawn from infographics displayed in the classroom to support their responses. Teacher Note: Students’ submitted essays can be scored using the following rubric.
|Constructing Explanations||Emerging (1 point)||Emerging (2 points)||Emerging (3 points)||Comments|
|The Nature of Science|
|Explains the misconception that scientific knowledge is absolute and never changes|| || || || |
|Restates that a theory is built upon evidence and can be improved or modified|| || || || |
|The Use of Evidence|
|Explains why their evolutionary evidence is important and how it is relevant to explaining the misconception|| || || || |
|Links the evidence from their evolutionary topic to explain the theory of evolution|| || || || |
|The Language of Science|
|Appropriate use of term scientific theory|| || || || |
|Used phrases that are consistent with the nature of science to explain the theory of evolution|| || || || |
|Total score||/18 |
| ||Name ______________________________|
| ||Date ______________________________|
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|Paraphrase or summarize information ||Paraphrase or summarize information ||Paraphrase or summarize information ||Paraphrase or summarize information |