Evolution & Natural Selection
Reading Comprehension Packet with Illustrations
Name: __________________________
Class: __________________________
Section 1 — Charles Darwin and the Galápagos Islands
Charles Darwin studied organisms on the Galápagos Islands and noticed that animals such as finches
had different beak shapes adapted to different food sources. These observations helped him develop
the theory of evolution by natural selection.
Questions
1. What observations did Darwin make in the Galápagos Islands?
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2. How did finch beaks demonstrate adaptation?
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Section 2 — Natural Selection
Natural selection occurs when organisms with beneficial traits survive and reproduce more successfully
than others. Over time these traits become more common in the population.
Questions
1. What conditions are necessary for natural selection?
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2. Why does variation matter in populations?
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Section 3 — Plant Adaptations
Plants also evolve adaptations to survive in their environments. For example, some plants develop
thick leaves to store water in dry climates while others grow large leaves to capture sunlight in forests.
Questions
1. What are some plant adaptations?
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2. Why might plants evolve different leaf shapes?
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Section 4 — Cladograms and Evolutionary Relationships
Cladograms are diagrams used to show evolutionary relationships between organisms. Branch points
represent common ancestors.
Questions
1. What does a branch point represent?
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2. How do scientists use cladograms to study evolution?
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