Change Over Time

Evolution describes how species change over generations through natural processes.

Key Ideas

• Natural Selection: Individuals with beneficial traits survive and reproduce more, passing those traits on.
• Mutation and Variation: Random changes in DNA introduce new traits.
• Adaptation: Populations become better suited to their environments over time.
• Speciation: The formation of new species when populations become isolated.

Real-World Connections

• Bacteria can become resistant to antibiotics through evolution.
• Darwin's finches in the Galápagos evolved different beak shapes to exploit various food sources.

Why It Matters

Evolution helps us understand biodiversity, extinction, and the adaptation of life on Earth.