Assertion and reason: mechanisms

Exercise and reference answers

Questions

1. Reason

   It works through changes in the distribution of variation across a group.

   Verdict

   Both are true; the reason explains the assertion.

   Assertion

   Evolution is a property of populations, not individuals.

2. Reason

   Fragmented populations diverge without interbreeding to average them out.

   Verdict

   Both are true; the reason explains the assertion.

   Assertion

   Isolation can speed the appearance of new species.

3. Reason

   Drift changes a population by chance.

   Verdict

   The assertion is false and the reason is true.

   Assertion

   Genetic drift favours the fittest.

Explanation