[Campbell Biology P.592] The Hawaiian archipelago is described as a "great showcase" for reg... | Practice Question

The Hawaiian archipelago is described as a "great showcase" for regional adaptive radiation. Which of the following factors, as suggested by the text and figures, best explains why these islands facilitate such extensive diversification of the silversword alliance?

  • A: The islands provided a highly competitive environment that drove rapid evolution.
  • B: The ancestral tarweed had pre-existing adaptations for diverse habitats before arriving.
  • C: The islands are geographically isolated and offer diverse, unoccupied ecological niches.
  • D: The consistent climate across the Hawaiian archipelago led to stable environmental pressures, encouraging specialization.

Explanation

The text explains that regional adaptive radiations occur when a few organisms reach a new, often distant location where they face little competition. The Hawaiian archipelago is geographically isolated and consists of islands of different ages with diverse habitats, providing ample unoccupied ecological niches for the ancestral tarweed to diversify into 'strikingly different adaptations' and new species, as seen in the silversword alliance.