Logical Reasoning

PT144 · S2 · Q21 Although the first humans came to

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Although the first humans came to Australia 56,000 years ago and undoubtedly brought new diseases with them, human-borne diseases probably did not cause the mass extinction of large land animals and birds that took place over the following 10,000 years.

Evidence

More than 55 different species went extinct 10,000 years ago, and no single disease could be fatal to animals across that many different species.

Conclusion

Human-borne diseases probably did not cause the mass extinction of large land animals and birds 10,000 years ago.

Evaluate

There's no conditional logic or quantifiers in there, so this probably isn't a great contender for symbolizing / turning into algebra.

Instead, we should probably just figure out how we would object to this argument.

Given That no single disease could take out 55 completely different species,

How Could We Still Say That human diseases did probably cause those extinctions?

What if there were more than one disease? What if a dozen or so different human-borne diseases collectively took out those 55 species?

What is the abstract form of that objection? We can help ourselves here by reminding ourselves whenever we're doing Parallel Flaw that they love to test some of the Famous Flaws: - Necessary vs. Sufficient - Part vs. Whole - Unproven vs. Proven False - Correlation vs. Causality - Ad Hominem - Sampling

This is Part vs. Whole, since the premise and the conclusion are repeating the same trait: PREMISE any single disease could not kill those 55 CONCLUSION human diseases did not kill those 55

Goal

Let's look for an answer that says

21.

Which one of the following arguments exhibits flawed reasoning that is most parallel to that in the argument above?

Even though high interest rates
No Part/Whole Relationship
The conclusion is correctly anti-causal sounding - high interest rates probably didn't cause the economic downturn. But to match the original argument, we'd need a premise saying "After all, no single interest rate could ever cause an economic downturn."
24% picked this
Correct
Even though I can fix
Why this is right
This is drifting a lot from the original, but it's still our closest match for Part vs. Whole. It's vulnerable to a similar objection we used with the original argument — even though no single disease alone could kill all those species, a bunch of diseases together could have killed al those species. Here we'd be saying — even though neither person alone can repair the apartment, the two of them together could repair it.
Skill tested: Parallel Flaw · how this choice captures the argument's function is the move to repeat next time.
39% picked this
Even though Lena, Jen, and
Bad Conclusion Match
A similar Part to Whole flaw would take a premise like, no single restaurant is liked by all three of them and then conclude restaurants aren't liked by all three of them This argument's conclusion (probably go home) is not recycling an idea from the premise. In the original argument and in correct answer (B), an idea from the conclusion (did not cause 55 extinctions / cannot repair whole apartment) shows up in the premise too. The argument didn't say, "Since each of the three people are likely to go straight home, it is likely that all three of them will go straight home."
25% picked this
Even though this painting is
Bad Conclusion Match
The conclusion of the original argument and the correct answer is about a group of things. This argument's conclusion is about one thing: this painting. The flaw in this argument is assuming that "Because most X's are Y, this specific X must be a Y."
11% picked this
Even though the influenza vaccine
No Part/Whole Relationship
This argument is just discussing whether the flu vaccine means you get no flu, a reduced flu, or you still get the flu. There's nothing like "no single vaccine can X" or "no single person who gets the vaccine is X".
1% picked this

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