Logical reasoning PrepTest 153 · Section 3 · Question 10

Incorrect. This would weaken the argument. If there's no evidence of one common means by which humans reduce the population of a particular type of animal, that would make it less likely to be true that humans drove that animal to extinction.

Incorrect. Irrelevant to our giant, ice age era sloths. The tree-dwelling sloths may be fundamentally different in a way that shielded them from harm when humans arrived in their habitat.

Incorrect. This would point to "failed to adapt to climate change" rather than "got slaughtered by humans." If giant sloths have trouble adapting, the end of an ice age might be hard for them.

Incorrect. "Not the only" is just an incredibly weak argument overall. That just means "at least one other" large mammal species also disappeared around the same time, and just knowing two animals disappeared doesn't tell us anything about whodunit.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen

Stimulus Summary:
Aw man, there are no giant sloths in the Americas anymore, and there haven't been since roughly the end of the last ice age. Kristen Bell is gonna be so sad. Scientists used to think they died of climate change, but now they're starting to think humans, upon their arrival in the Americas, were responsible for killing off the sloths.

Answer Anticipation:
What a bummer of a stimulus. It's our own ancestors' fault we don't get to see any giant sloths? But the stimulus doesn't give us any reason why the scientists have changed their thinking, so we're probably anticipating a correct answer choice that fills the gap. Maybe there's evidence that humans hunted and ate way too many sloths? Or sloths caught human diseases? Sloths were terrified of humans and died of heart attacks when they saw us?

Correct Answer:
Here we go, some actual evidence. If giant sloths that were isolated from humans survived the end of the ice age, then climate change doesn't inevitably extinct giant sloths. If they went extinct only after humans arrived, well, that's a pretty big clue linking humans to the disappearance of giant sloths. Cue the Law & Order "cell door slams shut" noise.

Key Takeaway:
When strengthening causal reasoning, always look for evidence that goes directly to causation. Eliminating a potential alternate cause, in this case climate change, will always succeed in strengthening a causal argument.