Learn on PengiAmplify Science (California) Grade 8Chapter 3: Mutation and Adaptive Traits

Lesson 2: Mutations and Adaptation

Key Idea.

Section 1

Mutation is Random

Key Idea

It is critical to understand that mutations are random.

Organisms cannot "try" to mutate because they need a new trait. A newt didn't get a poison mutation because snakes were eating it. The mutation happened by accident.

Section 2

Selection is Non-Random

Key Idea

While the arrival of a trait is random, its survival is not.

Once a mutation introduces a new trait, the environment decides its fate. If the mutation makes the newt more poisonous (Adaptive), it spreads. If the mutation makes the newt slower (Non-Adaptive), it disappears. This explains how random changes can lead to perfect adaptations.

Lesson overview

Expand to review the lesson summary and core properties.

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Section 1

Mutation is Random

Key Idea

It is critical to understand that mutations are random.

Organisms cannot "try" to mutate because they need a new trait. A newt didn't get a poison mutation because snakes were eating it. The mutation happened by accident.

Section 2

Selection is Non-Random

Key Idea

While the arrival of a trait is random, its survival is not.

Once a mutation introduces a new trait, the environment decides its fate. If the mutation makes the newt more poisonous (Adaptive), it spreads. If the mutation makes the newt slower (Non-Adaptive), it disappears. This explains how random changes can lead to perfect adaptations.