PrepTest 136, Section 2, Question 11
In the last year, biologists have learned that(29 more words not shown)
The reasoning in the argument(15 more words not shown)
- Akinds of things(8 more words not shown)
- Ba condition necessary(10 more words not shown)
- Ca cause and(2 more words not shown)
- Da correlation between(8 more words not shown)
- Echanges in our(9 more words not shown)
Reading the argument
Discovering more species doesn't stop other species from disappearing.
Suppose biologists once thought there were a million species of amphibians and now think there are five million. Those are made-up numbers to illustrate the change in knowledge. The newly discovered species didn't necessarily come into existence when the scientists learned about them. They might have been there all along.
Meanwhile, pollution could still be eliminating many species each year. Learning that the starting population of species was larger than we thought doesn't tell us that fewer are being lost. The author treats an increase in the number we know about as though it were evidence against a decline in the number that actually exists.
What we’re looking for
For the flaw question, I'd put the confusion this way: what we know about the world versus what's happening in the world. The answer may say that abstractly, so connect each part back to the discoveries and the claimed extinctions.
Working the answers
- A
A kind of thing could be a species; individual frogs would be things belonging to that species. Confusing those would mean treating the number of individual animals as though it were the number of species, or the other way around. Both the discovery and the environmentalists' claim concern species. The shift here is between knowledge and reality, not species and individuals.
- B
The author doesn't take one way of producing an outcome and mistake it for a requirement for that outcome. The reasoning tries to use newly learned information about species to challenge ongoing extinctions. That is a different mistake.
- C
The environmentalists say pollution eliminates species. Confusing cause and effect would involve treating the extinctions as the cause of the pollution. The author doesn't do that; the author questions the claim on the basis of the discoveries.
- D
We aren't told that two things vary together and then asked to accept that one causes the other. There is a claim about pollution causing losses, but the author's reason for doubting it concerns how many species have been discovered. Merely mentioning a cause doesn't make this a mistake about correlation.
- ECorrect
Our knowledge has changed: scientists now know of more species. That needn't mean the species themselves have increased or that pollution is eliminating fewer of them. Newly discovered species could have existed for a long time while other species continued to disappear. The premise and the environmentalists' claim can both be true.
More Flaw questions
Learn the LSAT our way
Our platform drills Flaw questions at your level and adjusts as you improve.