Evaluate the hypothesis that females prefer to mate with males whose feathers are a brighter blue.

Explain how natural selection can cause mate selection behaviour patterns to develop in a species such as eastern bluebirds.

Another type of behaviour is altruistic behaviour. Outline an example of altruistic behaviour.

Strengths:
a. (slight) increase in mate choice at higher male brightness index;

Weaknesses:
b. dots are scattered without a trend/no clear correlation
OR
most females choose mates around normal (brightness);

c. insufficient data/information provided;

Allow any other data-based statement.

a. natural selection favours specific types of mate selection/behaviour;

b. (behaviour/mate selection) increases the chances of survival/reproduction;

c. chosen organisms/males will leave more offspring;

d. pass on gene(s) for behavior to offspring;

e. (behaviour/allele) will become more prevalent/frequent in a population;

vampire bats share blood to ensure survival;

Other verified, outlined example.

Most candidates managed to provide at least one evaluation statement, but it was difficult for many to provide a complete evaluation.

It was difficult for many to provide focused answers for this question, although most candidates could provide valid partial explanations.

A large number of candidates could outline a valid example, but many answers lacked precision, either because "vampire" bats were not specified or the behaviour description was absent; a number of irrelevant examples were seen, including examples of human behaviour.