Question

based on the theory of island biogeography, which of the following is the most likely reason that an island in the ocean that is 5 kilometers from a continent would have a higher number of species than one that is 15 kilometers from a continent?
a there are more species that have the ability to travel 5 kilometers than can travel 15 kilometers.
b islands that are closer to continents always have a wider range of habitats than more distant islands do.
c there are smaller populations of each species on islands that are at greater distances from continents.
d islands that are closer to continents always have more ecological niches than more distant islands do.

Explanation:

The theory of island biogeography states that the number of species on an island is determined by the balance between immigration and extinction. Islands closer to the mainland (source of species) are more likely to receive immigrants. Species have a better chance of reaching an island 5 km from the continent compared to one 15 km away. Option B is incorrect as habitat range is not directly related to distance from the continent in this context. Option C is about population size, not the number of species. Option D about ecological niches is not the main factor here.

Answer:

A. There are more species that have the ability to travel 5 kilometers than can travel 15 kilometers.