PrepTest 89, Section 2, Question 3
Biologist: DNA analysis shows that Acacia heterophylla, a tree native to the Indian Ocean's Réunion Island, is descended from the Hawaiian tree Acacia koa. Some think this occurred because A. koa seeds floated from Hawaii to Réunion, but that explanation is implausible, since the seeds will not germinate after being soaked in seawater. Moreover, both trees grow in the mountains, not near the shore. Seabirds sometimes carry seeds great distances, so they probably caused the dispersal.
Biologist: DNA analysis shows that Acacia heterophylla, a tree native to the Indian Ocean's Réunion Island, is descended from the Hawaiian tree Acacia koa. Some think this occurred because A. koa seeds floated from Hawaii to Réunion, but that explanation is implausible, since the seeds will not germinate after being soaked in seawater. Moreover, both trees grow in the mountains, not near the shore. Seabirds sometimes carry seeds great distances, so they probably caused the dispersal.
Biologist: DNA analysis shows that Acacia heterophylla, a tree native to the Indian Ocean's Réunion Island, is descended from the Hawaiian tree Acacia koa. Some think this occurred because A. koa seeds floated from Hawaii to Réunion, but that explanation is implausible, since the seeds will not germinate after being soaked in seawater. Moreover, both trees grow in the mountains, not near the shore. Seabirds sometimes carry seeds great distances, so they probably caused the dispersal.
Biologist: DNA analysis shows that Acacia heterophylla, a tree native to the Indian Ocean's Réunion Island, is descended from the Hawaiian tree Acacia koa. Some think this occurred because A. koa seeds floated from Hawaii to Réunion, but that explanation is implausible, since the seeds will not germinate after being soaked in seawater. Moreover, both trees grow in the mountains, not near the shore. Seabirds sometimes carry seeds great distances, so they probably caused the dispersal.
Which one of the following, if true, most strengthens the support for the biologist's hypothesis?
A. koa branches carrying seeds can remain afloat for prolonged periods of time.
There are mountain-nesting seabird species common to Réunion and Hawaii.
A. koa is thought to be descended from Acacia melanoxylon, a tree native to eastern Australia.
Ocean currents have sometimes carried buoyant objects from Hawaii to Réunion.
Many seabird species return to land very infrequently, and often do so only to breed.
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