PrepTest 115

Incorrect. This answer provides counterexamples—species that saw the supposed cause but not the effect. This weakens Fisch's argument.

Incorrect. These animals would have been subjected to the same climate without dying out, so they, too, serve as counterexamples. They also suggest that animals that had adapted to humans survived and those that didn't, didn't—evidence for Foster's theory.

Incorrect. This answer provides more examples of Foster's cause and effect going together, strengthening his view.

Incorrect. If anything, this suggests that the humans could have taken out the large mammals, which would support Foster's argument. (It requires too many jumps for it to really strengthen his argument, but it's more in that direction than in supporting Fisch's argument.)

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen

Stimulus Summary:
Fo: Large NA mammals went extinct when humans showed up, so they must have died off because of the humans.

Fi: The climate shifted too rapidly to adapt to, so that's the real cause.

Answer Anticipation:
When you have a two-speaker stimulus and it's not a Point at Issue question, be sure to ID which speaker the question stem is addressing. Here, we're focused on strengthening Fisch's argument.

Fisch makes an argument for a specific cause of large mammal extinctions. Foster does, as well, and we should be aware of it because incorrect answer will likely address it! However, we should focus on the cause that Fisch puts forward—climate change.

Since we're trying to strengthen a causal conclusion, we can look for the standard answers:
(1) Eliminate alternative causes (e.g., humans, as Foster posits)
(2) More instances of the cause and effect going together (a previous ice age that wiped out a lot of large mammals)
(3) A "control" group (an instance of the cause being absent without the effect)
(4) An answer that explains how the causality works

Answer Explanation:
This answer plays a role in an explanation for how climate change could have been responsible for the extinctions. If the large mammals couldn't move to warmer areas, and it's true that the climate change was so quick that species could't adapt (which is established in Fisch's premise), then the argument for the climate being the real culprit here is strengthened.

Key Takeaway:
Notice how many of the incorrect answers would be harder (or impossible) to eliminate if the question stem asked about Foster's argument. This is a common pattern when there are two viewpoints in the stimulus.