Science Lesson Kit · Teacher Resource
Natural Selection: Why Some Traits Become More Common — 5E Lesson Plan
Life Science · 55 minutes
Grade 6
5E lesson flow
01
Engage
7 min
Teacher Does
Display two different shell-color beetles before discussing birds.
Students Do
Identify variation and ask which information is missing.
Ask
- Did the birds create the variation?
Look For
Colors differed before the challenge.
02
Explore
12 min
Teacher Does
Reveal the 12/20 and 5/20 fictional survival cards.
Students Do
Compare proportions and distinguish observation from explanation.
Ask
- Does a higher fraction mean certainty?
Look For
12/20 is higher but not all survive.
03
Explain
10 min
Teacher Does
Connect inherited trait, survival probability and number of offspring.
Students Do
Build a sequence across several generations.
Ask
- What must be inherited for a population change to occur?
Look For
Passing on existing traits through reproduction.
04
Elaborate
13 min
Teacher Does
Switch the habitat from pale sand to dark rocks and challenge a one-habitat model.
Students Do
Revise the claim with context and uncertainty.
Ask
- Will the same trait always be useful?
Look For
Fitness depends on the environment.
05
Evaluate
13 min
Teacher Does
Hand out an unrelated cricket evidence problem.
Students Do
Calculate, justify, and name missing evidence.
Ask
- What observation would make your conclusion stronger?
Look For
Inheritance and offspring data across generations.
Student goal
I can use survival, inheritance and offspring evidence to explain why a trait may become more common in one environment.
Learning objectives
- Interpret fictional population data as evidence that inherited trait variations may change an individual's chance of surviving and reproducing in a particular environment.
- Explain how selection acts on existing inherited variation, not purposeful trait changes by individuals.
- Construct and qualify an explanation using trait, environment, probability, reproduction and a limit of simplified models.
Materials
- Fictional beetle survival cards
- Pale and dark habitat cards
- 20-count counters for each group
- New cricket transfer worksheet
Before class
- Label data as invented rather than real measurements.
- Use equal starting groups and never present survival as a guarantee.
- Ask students to identify when inherited variation already existed.
- Prepare the two environments without labeling a 'winner' in advance.
Prior knowledge
- Individuals in one species can differ.
- Traits may be inherited from parents.
- A fraction compares a part with a starting whole.
Vocabulary
- natural selection
- A process in which individuals with some inherited traits tend to leave more offspring in a particular environment.
- inherited trait
- A characteristic that can be passed from parents to offspring through genetic information.
- variation
- Differences in traits among individuals of the same species.
- population
- Members of the same species living in the same area.
- environment
- The living and nonliving conditions in a place.
- survival
- Staying alive through a period of time or challenge.
- reproduction
- Producing offspring that may inherit some parental traits.
- probability
- How likely an outcome is; not a guarantee for each individual.
- evidence
- Data or observations used to test an explanation.
Differentiation
- Offer shaded 20-square fraction cards and a sentence frame: 'In this sample ___ out of 20...'.
- Allow partner comparison before an individual written explanation.
- Extension: compare a mixed habitat with different predators and predict why no single trait is always best.
Assessment
- Correct 12/20 versus 5/20 comparison.
- Uses 'may' and refers to an inherited trait and offspring.
- Rejects purposefully acquired inherited change.
Exit ticket
Why is a higher survival rate not enough by itself to prove a trait will become more common in later generations?
Extension
Design a controlled simulation with different habitats and record trait frequency for five generations.