During his voyage on the Beagle, Charles Darwin made many observations that helped him develop his theory of evolution. He was also influenced by other early thinkers — including Lamarck, Lyell, and Malthus — as well as his own knowledge of artificial selection. Darwin’s book, On the Origin of Species, clearly spells out his theory of evolution by natural selection and also provides a great deal of evidence to support it.
- CA.9–12.IE.1.k, n; CA.9–12.LS.7.d; CA.9–12.LS.8.b
- NSES.9–12.C.3.1, 2, 4; NSES.9–12.F.2.1, 3; NSES.9–12.G.3.3, 4
- AAAS.9–12.5.B.5; AAAS.9–12.5.F.1, 4, 7, 9; AAAS.9–12.10.D.1, 2, 3; AAAS.9–12.10.H.1, 2, 3, 4
- McREL.9–220.127.116.11, 4; McREL.9–18.104.22.168, 5; McREL.9–22.214.171.124, 2; McREL.9–126.96.36.199
- State Darwin’s theory of evolution by natural selection.
- Describe observations Darwin made on the voyage of the Beagle.
- Identify influences on Darwin’s development of evolutionary theory.
- Explain how a species can evolve through natural selection.
artificial selection: process in which organisms evolve traits useful to humans because people select which individuals are allowed to reproduce and pass on their genes to successive generations
fitness: relative ability of an organism to survive and produce fertile offspring
Galápagos Islands: group of 16 small volcanic islands in the Pacific Ocean 966 kilometers (600 miles) off the west coast of South America, where Darwin made some of his most important observations during his voyage on the HMS Beagle
inheritance of acquired characteristics: mistaken idea of Jean Baptiste Lamarck that evolution occurs through the inheritance of traits that an organism develops in its own lifetime
Introducing the Lesson
Ask students to recall what they already know about Charles Darwin. (Sample answers: He developed the theory of evolution; he traveled to the Galápagos Islands.) Tell the class they will learn more about Darwin in this lesson.
Assign the activities Darwin and Natural Selection and Evolution and Adaptation at the URL below. The former activity involves the observations and deductions that led Darwin to form his theory. The latter activity explores how various species have evolved adaptations to their way of life.
Tell less proficient readers to make a main ideas/details chart as they read the lesson. Instruct them to divide a sheet of paper down the middle and record the main ideas on the left side and the details for each main idea on the right side. Advise them to write one main idea for each of the main headings in the lesson. LPR
Gifted students may be interested in reading Darwin’s own words. Suggest that they read Chapter 3, “The Struggle for Existence,” in Darwin’s book, On the Origin of Species. (They can access the chapter online at the URL below.) The chapter provides an overview of Darwin’s main ideas.
Discuss why Darwin waited so long to publish his theory of evolution as an example of how society influences science. Relate the discussion to current issues in science and society. For example, discuss social pressure to restrict stem cell research. Ask students to state their views on the issue.
Challenge groups of students to apply Darwin’s theory to explain the evolution to antibiotic resistance in bacteria. They can learn more about the problem at the URL below.
When you discuss the theory of evolution, make sure students do not have the misconception that a scientific theory is just any explanation, which is how the term theory is used in everyday language. Explain that a scientific theory, such as the theory of evolution, is a widely accepted explanation that is supported by a great deal of evidence and can explain many natural phenomena. You may want to show the video Isn't Evolution Just a Theory? (see URL below).
Reinforce and Review
Copy and distribute the lesson worksheets in the CK-12 Biology Workbook. Ask students to complete the worksheets alone or in pairs as a review of lesson content.
Have students answer the Review Questions listed at the end of the lesson in the FlexBook®.
Points to Consider
Darwin’s book On the Origin of Species is a major milestone in science. It introduced biology’s most important theory. It also provided an excellent example of how to think like a scientist. A scientist uses evidence and logic to understand the natural world. In this lesson, you read about some of the evidence Darwin used. This evidence included fossils and artificial selection.
- What other evidence might be used to show that evolution occurs? What about evidence based on molecules?
- Do you think it’s possible to see evolution occurring? How might that happen?