IB Biology D4.1: Natural selection (first exams in 2025)

This lesson can be purchased as part of the IB Complete course bundle (first exams 2025) at a heavily discounted price, formed of 40 fully resourced lessons, end of topic exams and student checklists. It can be found here

This PowerPoint contains everything you need to teach the Theme/Unit D4.1: Natural selection in the new IB Biology specification.

YouTube video is a preview of the full resource (does not include all slides)

This Powerpoint consists of over 80 slides and contains the followings:

• All the information the IB have included in the new spec.
• Clear diagrams
• Student friendly content
• Summary videos
• Student research tasks
• Clearly identified HL and SL content
• Student checklist
• Summary

The following content is included:

D4.1.1: Recognise that natural selection is the mechanism that drives evolutionary change.
D4.1.2: Explain the roles of mutation and sexual reproduction in generating variation.
D4.1.3: Identify and explain the biotic and abiotic factors that promote natural selection.
D4.1.4: Explain that differences in adaptation, survival and reproduction form the basis of natural selection.
D4.1.5: Recall that heritable changes lead to evolutionary change.
D4.1.6: Define sexual selection as a special case of natural selection.
D4.1.7: Describe the effects of sexual and natural selection through simulation of selection pressure.
D4.1.8: Define the concept of a gene pool.
D4.1.9: Describe the changes that occur in allele frequencies in geographically isolated populations.
D4.1.10: State the causes for the changes in allele frequency in the gene pool.
D4.1.11:  Differentiate among directional, disruptive and stabilising selection.
D4.1.12: Define Hardy-Weinberg equilibrium.
D4.1.13: Identify the Hardy-Weinberg conditions that need to be maintained for genetic equilibrium in a population