SAT Reading & Writing · Text Structure and Purpose
The Hawaiian silversword alliance includes an unusually diverse group of plants, ranging from trees to shrubs to ground-hugging rosettes,…
The Hawaiian silversword alliance includes an unusually diverse group of plants, ranging from trees to shrubs to ground-hugging rosettes, all descended from a single tarweed-like ancestor that colonized the islands. This dramatic diversification into such varied forms from one ancestral lineage illustrates how island colonization can, under the right conditions, be followed by rapid evolutionary radiation into a wide range of ecological niches.
Which choice best states the main purpose of the text?
Which choice best states the main purpose of the text?
Answer and explanation
Answer: B: To use a specific example of extreme diversification to illustrate a broader pattern of evolutionary radiation following island colonization
The passage moves from a specific, striking example, one ancestor producing trees, shrubs, and rosettes, to an explicit generalization about island colonization and evolutionary radiation more broadly. B captures that specific-to-general structure. A overstates the passage into a claim about overall plant success it never makes. C overgeneralizes a single lineage's history into a claim about all island plants, which the passage doesn't state. D invents a criticism of botanical classification that the passage never raises.
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