OG9 阅读 Q26

Choice B is the best answer. Reznick's team found that guppies, when moved from predator-ridden environments to a site where there was not the same level of predation, "evolved to mature later, and have fewer, bigger offspring in each litter, just like the guppies that naturally occurred in the cichlid-free streams," according to the fourth sentence of the last paragraph. If it were discovered that the new site into which Reznick released the guppies were inhabited by fish found to be as predatory as the cichlids in the original sites, this discovery would undermine Reznick's findings. Such a finding would mean that the pressure of predation on the guppies remained constant from one site to the next. As a consequence, some other factor or factors would be responsible for the developmental changes in the guppies that Reznick's team recorded.
Choice A is incorrect. If guppies examined in other parts of the globe were found to exhibit genetic shifts in traits at a different rate from the guppies Reznick examined, these findings would not undermine his research because they would have occurred outside the confines of his experimental conditions. Choice C is incorrect. If experimental evolution were shown to be harmful to the environment, this finding, though important, would not undermine Reznick's findings. Choice D is incorrect. If the descendants of Reznick's transplanted fish were proven to mature later than the guppies living below the waterfall, this finding would support, rather than undermine, Reznick's findings.