Describe one reason why the introduction of brown and black European rats may have led to the extinction of Darwin's rice rat.

Brown and black European rats have higher adaptive fitness.

Explanation:

According to evolutionary theory, the adaptive fitness of an organism is the ability to successfully survive and reproduce in specific environmental conditions. In this case, the invasive species may show to have higher adaptive fitness and better performance compared to a local one because their individuals have, for example, a higher ability to avoid predators, to find food, to reproduce, etc., thereby these individuals will be selected by natural selection in order to occupy this ecological niche.

They were competing for the same type of food.

Explanation:

The introduction of brown and black European rats may have led to the extinction of Darwin's rice rat due to competition for food and resources. These are the main factors that affects am organisms survival.

The brown and black rat were better adapted for survival and competition of the food and resources available which lead to the death and extinction of Darwin's rice rat.