SAT Question f8244f7c: Command Of Evidence answer and explanation

Choice D is the best answer because it most effectively uses data from the table to support Probst and colleagues’ conclusion about the hypothesis regarding the relationship between birds’ bill size and habitat temperature. The text states that although it has been hypothesized that birds’ bill size should increase with habitat temperature (an adaptation that reflects the fact that birds can release excess heat through their bills), Probst and colleagues concluded after studying mean bill surface area in North American thrashers that this hypothesis was not fully supported. In other words, Probst and colleagues did not observe the predicted positive relationship between mean bill surface area and habitat temperature in the thrashers they studied. The data in the table about the ocellated thrasher support Probst and colleagues’ conclusion because this species has the greatest mean bill surface area (3.26 cm²), but its habitat has the lowest mean maximum temperature in the warmest month (27.56°C). If the hypothesis were fully supported, species such as the ocellated thrasher that have colder habitats would likely also have smaller bills. Similarly, the data about the Bendire’s thrasher support Probst and colleagues’ conclusion because this species has the second-smallest mean bill surface area (1.98 cm²), yet its habitat has the highest mean maximum temperature in the warmest month (36.57°C). If the hypothesis were fully supported, the Bendire’s thrasher and other species with warmer habitats would also have larger bills. Because data in the table show that the ocellated thrasher and the Bendire’s thrasher have the opposite or near opposite of the hypothesized relationship between bill size and habitat temperature, these examples support Probst and colleagues’ conclusion that this hypothesis isn’t fully supported.