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D4.1.3—Overproduction and competition

Overproduction of offspring creates competition for limited resources, so individuals with advantageous traits are more likely to survive and reproduce.

Syllabus
First assessment 2025
Objective
D4.1.3
Level
HL

Exam analysis

Chance of appearing1%of analysed past papers
Latest appearanceMay 2015
Most common paperPaper1
Typical marks1

Common command terms

  • Outline
  • Identify
  • State
  • Explain

Recent exam appearances

May 2015Paper1 ["HL"] · TZ218[ 1 ]D4.1.3—Overproduction and competition
Practice this objective

Coverage 2015–2015 · Updated 16 Jul 2026

Overproduction Creates Competition for Limiting Resources

Populations can produce more offspring than the environment can support, so individuals of the same species compete for limiting resources.

Food, water, light, mineral ions, territory, nesting sites or mates can limit carrying capacity. Individuals that obtain these resources more successfully are more likely to survive and reproduce.

Potential offspring exceed available resources → intraspecific competition occurs → heritable differences affect resource access → reproductive success differs.

When food limits a population, individuals whose inherited feeding traits increase food acquisition may leave more offspring than competitors.

Overproduction means reproductive potential exceeds long-term support; it does not require the population to remain permanently above carrying capacity.

Overproduction and competition

Assessment in practice

1–3 marks
How it is assessed

This objective is assessed through structured response, commonly using Outline / Identify / State.

Command terms

Outline / Identify / State / Explain

What earns marks

Build the answer around this relationship: Overproduction means not all offspring survive to reproduce.

Representative question

Question 1

[Maximum number: 4]

Outline how overpopulation of a species in a given environment may lead to evolution.

Retrieve the Core Natural Selection Route

Core D4.1 examples follow the same causal route: heritable variation exists, a selection pressure acts, individuals differ in fitness, and alleles linked to higher reproduction become more common. Endler’s guppies and sexual selection are evidence versions of the same chain.

  • mutation creates alleles; meiosis and fertilization reshuffle combinations
  • overproduction, limited resources, and abiotic factors filter variants
  • passing alleles to offspring in a particular environment
  • Endler controlled predation pressure and guppy colour patterns changed

Core Natural Selection

Core natural-selection exam answers should never stop at “the best adapted survive.” They need the chain: heritable variation exists, a named pressure acts, some individuals have higher fitness, and their alleles become more common over generations. Use this for abiotic pressure, overproduction, sexual selection, and Endler-style data.

  • Explain natural selection using heritable variation, selection pressure, differential survival/reproduction, and population change.
  • Distinguish mutation/recombination as sources of variation from selection as the filtering process.
  • Use examples such as abiotic pressure, sexual selection, or Endler guppy data to support the chain.

Concept essentials

  • Overproduction means not all offspring survive to reproduce.
  • Limited resources create competition among individuals.
  • Competition makes advantageous heritable traits more likely to spread.