AC9S10U02: Evolution by Natural Selection

Heritable variation, selection pressure and differential reproduction change populations over generations.

By the end of this lesson, you should be able to:

• Populations contain heritable variation.
• Selection pressures affect survival and reproductive success.
• Fossils, anatomy, biogeography and molecular evidence support evolutionary theory.

Students should understand inherited variation, genes and populations. AC9S10U01 is the strongest prerequisite because natural selection acts on heritable variation.

Learning sequence: Identify variation → Apply selection pressure → Track reproduction → Evaluate evidence

Core teaching

• Populations contain heritable variation.
• Selection pressures affect survival and reproductive success.
• Fossils, anatomy, biogeography and molecular evidence support evolutionary theory.

Key vocabulary and ideas

• heritable variation
• selection pressure
• survival and reproduction
• population change
• multiple evidence lines

• Individuals evolve because they need to: Track changes in trait frequency across a reproducing population.
• Natural selection is random: Separate random sources of variation from non-random survival and reproduction under a selection pressure.

Keep the Year 10 boundary: Do not describe evolution as progress toward perfection. Do not claim organisms change traits deliberately in response to need.

1. Use a coloured-token population and remove tokens according to one environmental rule.
2. Reproduce survivors and graph trait frequency over three generations.

Work through the sequence Identify variation → Apply selection pressure → Track reproduction → Evaluate evidence, explaining the evidence or mechanism at each step before moving on.

1. Explain why heritable variation must exist before natural selection can change a population.
2. Distinguish a selection pressure from an adaptation using one biological example.
3. Explain antibiotic resistance without saying that individual bacteria changed because they needed to survive.
4. Name two independent lines of evidence for evolution and explain what each contributes to the theory.

A population becomes more resistant to an antibiotic over many generations. Evaluate the claim that individual bacteria changed because they needed to survive.

Reasoning standard: state the claim, use relevant evidence or a scientific mechanism, and explain why the evidence supports the conclusion without overclaiming.

What is the central idea?

Heritable variation, selection pressure and differential reproduction change populations over generations.

What should a strong response do?

Use the sequence Identify variation → Apply selection pressure → Track reproduction → Evaluate evidence. Connect the evidence, mechanism or data to the claim.

What common trap should I avoid?

Individuals evolve because they need to: Track changes in trait frequency across a reproducing population.

1. A drought leaves mainly hard seeds in a bird population’s habitat. Birds vary in beak depth and deeper-beaked birds reproduce more successfully. Explain how the population could change over several generations.
2. Evaluate the statement, “Natural selection is random.” Separate the origin of variation from differential survival and reproduction.
3. Use fossil, anatomical, biogeographical or molecular evidence to construct an evidence-based argument supporting evolutionary relatedness.

Review hint: Use precise scientific vocabulary, show the relevant mechanism or evidence, and state any limitation or uncertainty when the evidence does not justify a stronger claim.

• I can explain and apply: Populations contain heritable variation.
• I can explain and apply: Selection pressures affect survival and reproductive success.
• I can explain and apply: Fossils, anatomy, biogeography and molecular evidence support evolutionary theory.

Exit ticket: Explain the core idea in 3–5 sentences and apply it to one new example without copying the worked model.

Australian Curriculum v9.0 — AC9S10U02: use the theory of evolution by natural selection to explain past and present diversity and analyse the scientific evidence supporting the theory

Victoria — VC2S10U05, Levels 9–10: Levels 9–10 evolution by natural selection, variation, isolation, adaptation and evidence. Victorian Science is banded across Levels 9 and 10, so the VC2S10 code identifies the band rather than a single school year.

NSW: Stage 5 Genetics and evolutionary change — diversity of living things and evolution (SC5-GEV-01). Where NSW places the closest concept in another Stage or spreads it across focus areas, this page states that relationship rather than claiming a false one-to-one Year 10 equivalent.

Use these links to move through the learning sequence rather than studying this code in isolation.

• AC9S10U01
• AC9S10H01

• Australian Curriculum v9.0 — Science
• Victorian Curriculum F–10 Version 2.0 — Science
• NSW Science 7–10 Syllabus (2023) — outcomes

Curriculum equivalents for The theory of evolution by natural selection to explain past...

Mapped skill: use the theory of evolution by natural selection to explain past and present diversity and analyse the scientific evidence supporting the theory

These references identify matching or closely related learning. Curriculum sequence, terminology and depth vary, so teachers should use the mapped skill and lesson difficulty to confirm suitability.

Australian Curriculum v9.0 is the canonical source for this SkillrHub lesson. Victoria and NSW entries name the closest published state codes or outcomes; international entries are planning references rather than claims of identical curricula.