What is revealed by ‘mother bird removing the eggshells’?

Directions: Read the passage and answer the question that follows.

It is often believed that human behaviour is pre-determined by factors of nature, as some very prominent anthropologists and everyday people say. It is stated that political conservatives have sometimes favoured genetic explanations of behaviour and example of genetics would be a mother bird that removes the eggshells from the nest after the chicks have hatched. The mother bird does this because the outside of the eggshell is camouflaged and once hatched the inside is revealed which is not camouflaged. The broken eggshells will be seen by predators and will endanger the entire nest. Throwing out the broken pieces is an automatic response favoured by natural selection because birds that practice this behaviour have more surviving offspring.