Question

According to island biogeography, what is the relationship between an island's distance from the mainland and the number of species present on the island?
a. There is no relationship between the distance from the mainland and the number of species found on an island.
b. The farther an island is from the mainland, the larger the number of species found on the island.
c. The closer an island is to the mainland, the fewer the number of species found on the island.
d. The farther an island is from the mainland, the fewer the number of species found on the island.
e. The closer an island is to the mainland, the fewer the number of species found on the island; and the farther an island is from the mainland, the larger the number of species found on the island.

Answer 1

Answer: D. The farther an island is from the mainland, the fewer the number of species found on the island.

Explanation: Island biogeography estimates the species richness on a new island using environmental factors. Species richness of an island is the number of different species inhabiting an island.

Islands that are far from mainlands have fewer species because the mainland is a source of new species which migrate to the islands to colonize them. Another factor that decides the number of species inhabiting an island is the island size.