Nothing Tries to Adapt

The motion: “Organisms adapt to their environment during their lifetime, and pass those adaptations on.”

Your opponent: Charles Darwin · Course: Pearson Edexcel International GCSE Biology (4BI1) · Assessment objectives: AO1, AO2

This is the wrong answer — and it is the one almost everyone gives under pressure. Darwin will make you say why it fails.

What you are asked to argue

You must DEFEAT this motion with a mechanism. Naming natural selection is not enough; you must say what varies, what is selected, and what is inherited.

What the specification expects you to bring

• Variation within a population and where it comes from
• Selection pressure and differential survival
• Reproduction and the inheritance of the advantageous variant
• Time and the change in allele frequency across generations
• Why an individual does not evolve — populations do

Positions that are defensible

Disagreeing with the figure is not an error. Any of these can score full marks if argued well:

• That some acquired changes ARE heritable through mechanisms outside the specification, provided the learner is precise that this does not rescue the motion as stated
• That artificial selection is a disanalogy in one respect — there is a selector — and saying so is a strength

Common misconceptions this debate is built to expose

• Wrong: An individual organism evolves to suit its environment.
  The correction: Individuals do not evolve. A population changes because individuals carrying an existing variant survive and reproduce more than others.
• Wrong: Organisms develop features because they need them.
  The correction: Need cannot cause a variation. The variation is already present, by chance, before the environment selects it.
• Wrong: Bacteria become resistant when exposed to an antibiotic.
  The correction: Some bacteria are already resistant. The antibiotic kills the rest, so the resistant ones become the population. The antibiotic selects; it does not instruct.
• Wrong: 'Survival of the fittest' means the strongest survive.
  The correction: Fitness means reproductive success in a given environment. In many environments the smallest, the least conspicuous or the most fertile is the fittest.

What passing it proves

The full mechanism in the correct order, applied to at least one example with the pre-existing variation made explicit, and the acquired-characteristics case defeated by argument rather than assertion.

Why them?

Read the life before you argue with it — the case you are about to meet was built by a real person, over a real career:

• The life of Charles Darwin — Author of On the Origin of Species · Naturalist · 1809–1882

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