SAT Reading & Writing · Command of Evidence (textual)
Galápagos flightless cormorants have small, reduced wings along with genetic changes in pathways related to skeletal development. A…
Galápagos flightless cormorants have small, reduced wings along with genetic changes in pathways related to skeletal development. A researcher claims that a single identified gene mutation is the sole cause of the birds' flightlessness. Which finding would most directly undermine the researcher's claim?
Answer and explanation
Answer: B: Multiple genetic changes across several developmental pathways have been associated with the flightless trait, and selection pressures related to body size and diving ecology likely also played a…
The researcher's claim requires a single mutation to be sufficient on its own, and B directly challenges that by showing multiple genetic pathways and separate ecological selection pressures were all likely involved, which is inconsistent with one mutation being the sole cause. A restates a basic anatomical fact without addressing genetic causation. C and D are background facts about geography and diet unrelated to the genetic-cause question.
More Command of Evidence (textual) questions
- Question 1A team analyzing an iridescent glass fragment recovered from a first-century Roman burial proposed…
- Question 2A curator claims that a museum's newly acquired painting was created by a specific well-known…
- Question 26A popular claim holds that the QWERTY keyboard layout was deliberately designed to slow typists…
- Question 28A theater historian claims that a controversial ending added to a classic play during a famous…
- Question 29A stream ecologist claims that the isotopic signature of marine-derived nitrogen found in forest…
- Question 52Cleaner wrasse fish sometimes "cheat" by biting a client fish's protective mucus instead of…
Learn the method behind questions like this one
The SAT Reading & Writing course teaches each tested skill through lessons, step-by-step solutions to sample problems, the complete study guide and full-length practice tests.