PrepTest 62, Section 2, Question 7
By Brandon Beaver | Published October 29, 2024
Type: Paradox
Difficulty:
Explanations
This isn't an argument, just facts about some birds and their beaks. In particular, two groups—one captive, one wild—have surprising discrepancies in beak size.
It turns out to be a Paradox question, so our job is to explain why the wild birds' beaks would decrease in average size compared to the captive birds.
This discrepancy most probably stems from some sort of natural selection or competitive pressure out in the wild that the captive birds wouldn't have to face.
Let's see if that prediction will bear any fruit.
A
Nah, this doesn't help. If this is true, then it would have been a pain to catch the long-beaked wild birds over the entire course of the three decades of study and we would expect the discrepancy to remain more or less constant over the time period, not to change.
B
Nope. This presents the same problem as A but actually makes it worse. That is, if the big-beaked birds are easier to catch, why are beaks decreasing in size over thirty years?
C
Yes, this is it. And right in line with our prediction. If short-beaked birds get the food, then long-beaked birds would die off, leaving around an increased proportion of short-beaked birds to be studied. Captive birds wouldn't deal with these same competitive forces, so their beaks didn't need to adapt.
D
Nah, this is irrelevant. Body size staying the same has no immediate impact on either group's change in beak size (or the lack thereof).
E
Nope. It's possible this might have corrupted some of the wild bird data, but we don't know if the birds measured twice were the small-beak birds.
Passage
Researcher: Over the course of three decades, we kept recor
Question 7
Which one of the following, if true, most helps to explain t