-According to the theory of sea-floor spreading, oceanic islands, such as the Hawaiian Islands depicted in the accompanying figure, form as oceanic crustal plates move over a stationary "hot spot" in the mantle. Currently, the big island of Hawaii is thought to be over a hot spot, which is why it is the only one of the seven large islands that has active volcanoes. What should be TRUE of the island of Hawaii?
1) Scientists in search of ongoing speciation events are more likely to find them here than on the other six large islands.
2) Its species should be more closely related to those of nearer islands than to those of farther islands.
3) It should have a rich fossil record of terrestrial organisms.
4) It should have species that are not found anywhere else on Earth.
5) On average, it should have fewer species per unit surface area than the other six islands.

Question

Quizplus · Accepted Answer

The island of Hawaii, being the youngest and currently over a hot spot, is likely to have ongoing speciation events due to its active volcanic activity (1). Its species should indeed be more closely related to those of nearer islands than to those of farther islands due to the sequential formation of the islands from the hot spot (2). It should have species that are not found anywhere else on Earth because of its unique environment and ongoing volcanic activity promoting isolation and speciation (4). Lastly, being the youngest island, it would have had less time for species to accumulate, leading to fewer species per unit surface area compared to older islands (5). The rich fossil record (3) is less likely because the island is geologically young.

-According to the Theory of Sea-Floor Spreading, Oceanic Islands, Such