An island off the coast of Africa contains a larger percentage of specialist species than generalist species. Which of the following describes the most immediate effect if an invasive generalist species is introduced to the island?

As competition for resources increases, the population size of the island's specialist species will decrease.

Explanation:

The options you were given are:

As predation increases, the population size of the invasive generalist species will decrease. As competition for resources increases, the population size of the island's specialist species will decrease. As resources are partitioned, the population sizes of both the generalist species and the specialist species will increase. As niches overlap, the invasive generalist species will be outcompeted by the island's specialist species.

A generalist species is a species capable of surviving in different environments and with different resources. Omnivores, species that feed on food of both animal and plant origin, are usually generalists. The raccoon is a good example of a generalist species.

A specialist species is different - it can thrive only in specific environmental conditions and use specific resources as it usually has a limited diet. Herbivores are often specialists, such as the monophagous koala, which feeds almost entirely on eucalyptus leaves.

An invasive species is any species that is not native to an ecosystem and causes harm. As the overall population increases, competition for resources arises, and this leads to a decrease in population of specialist species, as its resources are more limited than generalists'.