Explanation
Correct answer: B.
Choice B is the best answer because it most accurately states the main idea of the text. The text notes that Tetragnatha spiders have diversified their web architecture, or web design, through adaptive radiation and that Alicea-Serrano et al. investigated whether silk material properties were also affected by this process. After examining chemical composition, tensile strength, and viscosity of silks from three Tetragnatha species, the team found significant interspecies variation in these material properties, meaning that there were observable differences in these traits across the studied species. In the context of the study’s research question, this finding suggests that the material properties of silk from species of Tetragnatha spiders have indeed diversified during adaptive radiation, which is the main idea of the text.
Why the other choices are wrong
Choice A
Choice A is incorrect because the text doesn’t compare the rate of diversification in web architecture to the rate of diversification in silk properties. Although the text notes that web architecture diversified “over a relatively short timescale,” it doesn’t make a corresponding temporal claim about silk properties or suggest that one changed more rapidly than the other.
Choice C
Choice C is incorrect because the study investigated silk properties as a separate question, not as an explanation for differences in web architecture. The researchers discussed in the text investigated whether silk properties were “similarly affected” by adaptive radiation, not whether they caused the variations in web design.
Choice D
Choice D is incorrect because it contradicts the findings described in the text. The study found “significant interspecies variation” in silk biomaterials, suggesting that adaptive radiation did affect the properties of Tetragnatha spiders’ silk rather than showing that adaptive radiation cannot explain silk variation.