D4.1 Natural selection

Natural selection explains how heritable variation, selection pressures, differential survival, reproduction and allele-frequency changes drive evolutionary adaptation in populations in evolving populations.

What you’ll learn

8 learning objectives

Choose one objective for a focused lesson, or study the complete topic.

Exam analysis

An aggregate view of how the complete D4.1 Natural selection appears across past papers.

Chance of appearing30%of analysed past papers

Latest appearanceNovember 2025

Most common paperPaper2

Most tested objectives

D4.1.1—Natural selection as mechanism19 questions
D4.1.2—Roles of mutation and sexual reproduction8 questions
D4.1.10 (HL)—Allele frequencies7 questions

Common question formats

Process explanation
Data analysis
Definition or recall
Calculation
Diagram interpretation
Experimental design
Comparison

Exam question appearances

November 2025Paper2 ["SL"] · TZ36(c)[ 7 ]D4.1.1—Natural selection as mechanism

November 2025Paper1A ["SL"] · TZ129[ 1 ]D4.1.7—Sexual selection

May 2025Paper1A ["SL"] · TZ229[ 1 ]D4.1.2—Roles of mutation and sexual reproduction

May 2025Paper1A ["SL"] · TZ129[ 1 ]D4.1.8—Modelling selection

May 2025Paper2 ["SL"] · TZ12(b)[ 2 ]D4.1.4—Abiotic factors as selection pressures

Coverage 2010–2025 · Updated 16 Jul 2026