#15 - Extinction is the way of nature. Scientists estimate

[Administrator]

Complete Question Explanation

Flaw in the Reasoning. The correct answer choice is (E)

The argument is that since extinction is a natural process, human use of technology cannot have caused any extinctions that would not have been caused by natural processes, anyway.

The argument unjustifiably assumes that in the absence of technology as a cause would have occurred anyway with natural processes as a cause. The argument treats the species that have become extinct in modern times as, uniformly, species whose time had come.

You are asked to identify a reasoning error, so you should focus on the fact that it is entirely plausible that even if many of the species would have naturally become extinct, human use of technology has exacerbated the problem.

Answer choice (A): The author acquiesces that human technology has damaged the environment, but simply argues that the supposedly resultant extinctions would have occurred anyway. This choice is wrong.

Answer choice (B): The author's flaw is based on assuming that extinctions and threats of extinctions are always no different from that caused by natural processes. The correct choice would have to address that causal source, not simply discuss the effects, so this choice is incorrect.

Answer choice (C): The argument is based on the general premise that species, over time, have an extinction rate of over 50%. It is not relevant whether the author fails to consider a few undiscovered species, because it is implausible that such discoveries would affect that general premise. Even if such discoveries did drastically affect the 50% rate, such discoveries would probably not affect the rate with respect to the species in which the author is most likely interested.

Answer choice (D): The author does not need to cite specific scientists who do not support the theory that over half of all species that have existed have become extinct. The description of the scientific estimate in the first sentence implies strongly that there is uniform scientific consensus, so this choice is not even relevant to the actual situation, and thus is incorrect.

Answer choice (E): This is the correct answer choice. The author asserts that the species that have become extinct in modern times would have become extinct in modern times even without the adverse effects of modern technology, but the author provides absolutely no reason to believe his assertions.

[Tamirra]

Hi,

I got the right answer for this but it took about 100 years.

Flaw questions are my nemeses in LR. What's the best way to approach these larger passages that are kind of dense? Prephrasing? I actually bought the tablet LSAC is using to administer the LSAT so I'm also playing with the highlighters and the underlining feature.

Thanks!
Tamirra

[Claire Horan]

Hi Tamirra,

VIEWSTAMP, VIEWSTAMP, VIEWSTAMP. That's the best way to approach all of the passages. But you are wondering if there are any other tips for very dense passages. The denser the passage, the slower you should read, the smaller chunks you should read at a time, and the more often you should summarize (in your head) what you are reading.

Read slowly, pausing often to put what you have just read into your own words. When you get to the end of each sentence, summarize what the sentence said. Then do the same at the end of the paragraph. Write a few words in the margin summarizing the paragraph (in notes, not in full sentences). You will then have your summaries in the margin that together show you, very quickly, the structure and scope of the passage.

When I model this for students, every single one thinks it is too slow at first. But, more time on the front end means you understand the passage better and can approach the questions more effectively!

[Tamirra]

Thanks!

It just never occurred to me that I could use techniques from the other disciplines! Duh! Some of the denser passages are indeed mini RCs.

Tamirra

[KG!]

Hi! How would we categorize this flaw? I saw the argument as making a temporal flaw. Is this the case? Would you agree that this argument assuming that just because something always happened in the past (extinction of species) that it will continue to happen (hence the absence of technology). This thought process led me to answer choice E.

Please let me know if this was the correct categorization. Thanks!

[Jeff Wren]

Hi KG,

I agree that the temporal flaw is a great way to classify the flaw here. The author is assuming what has happened in the past (natural extinctions) will always continue in the present and future.

You could also think of the flaw in terms of causality. The extinction of different species may have different causes, so even if some species went extinct due to natural causes, it is still possible for other species to go extinct due to human technology, and those species may not have been the same ones that would have gone extinct due to natural causes, which is what Answer E addresses.