Q25 - By examining fossilized beetles

[nmop_apisdn2]

This is a necessary assumption question.

The argument is basically about that they examined fossils of species that still exist, they now know the maximum temperature that could have existed at that place and period.

(A) is incorrect because this is an unnecessary comparison of what weather beetles can tolerate more, and this is clearly out of scope.
(B) is wrong because we are not concerned with if the fossils are from different periods. The argument is trying to establish that through dating from the beetles, they were able to find out the maximum temperature of that place and period.
(C) is incorrect because the accuracy of dating whatever insects and how its more accurate for beetles is completely out of scope.
(D) is incorrect because the highest actual summer temperature does not have to be the same (equal) to the average highest temperature that could be tolerated by the beetles. In other words, the HIGHEST temperature does not necessarily HAVE to be the same as the average highest temperature in order to establish the highest temperature at that place/period. This answer choice is too strong anyway.

Finally, (E) is the correct answer choice because if we used the negation technique, we get, "The temperature tolerances of the beetle species DID change significantly during the 22,000 year period". We can see that this would ruin the argument entirely, because if the temperature tolerances changed significantly, then there is no way whatsoever that they would have been able to accurately assess the highest temperature at that place/period based on the contemporary beetles since, well, their temperature tolerances have completely changed!

[ohthatpatrick]

Very well done!

As you stated in another post, most correct answers to necessary assumption questions are ruling out the possibility of an objection to the argument.

Hence, many correct answers are phrased like (E), saying "_____ did NOT happen." or "It is NOT the case that _____".

These are ripe for negating! In fact, when an answer is phrased as though it's ruling something out, my immediate response is to remove the negative word and see if the statement becomes an objection to the argument.

Keep up the good work.