LSAT 149 – Section 4 – Question 02

LSAT 149 - Section 4 - Question 02

December 2017

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Question
QuickView		 Type Tags Answer
Choices		 Curve Question
Difficulty		 Psg/Game/S
Difficulty		 Explanation
PT149 S4 Q02
+LR
+Exp
Weaken +Weak
Causal Reasoning +CausR
A
2%
155
B
95%
163
C
1%
149
D
1%
151
E
0%
150
128
136
144
 +Easier 147.325 +SubsectionMedium

When the ancient fossils of a primitive land mammal were unearthed in New Zealand, they provided the first concrete evidence that the island country had once had indigenous land mammals. Until that discovery, New Zealand had no known native land mammals. The discovery thus falsifies the theory that New Zealand’s rich and varied native bird population owes its existence to the lack of competition from mammals.

Summarize Argument
The author concludes that New Zealand’s rich and varied native bird population was not caused by the lack of competition from mammals. This is based on evidence that New Zealand once had indigenous land mammals.

Notable Assumptions
The author assumes that the indigenous land mammals on New Zealand existed at the same time as New Zealand’s birds existed. The author also assumes that there were enough members of indigenous land mammal species to create competitive pressure with New Zealand’s birds.

A
The unearthed land mammal is only one of several ancient land mammals that were indigenous to New Zealand.
The number of different kinds of mammals doesn’t impact the significance of the evidence. And even if it did, (A) might strengthen by providing additional reason to think birds faced competition from mammals.
B
The recently discovered land mammal became extinct long before the native bird population was established.
This undermines the assumption that the indigenous land mammal recently discovered actually competed with New Zealand’s birds. If it was extinct before the birds came around, it’s not evidence that birds faced competition from land mammals.
C
The site at which the primitive land mammal was unearthed also contains the fossils of primitive reptile and insect species.
The argument concerns competition between birds and land mammals. Reptiles and insects are not mammals and are therefore irrelevant.
D
Countries with rich and varied native land mammal populations do not have rich and varied native bird populations.
We know NZ has a rich and varied bird population, which, in connection with (D), would imply that it doesn’t have a rich and varied population of land mammals. But this doesn’t affect anything concerning the recently discovered mammal and how it might have affected birds.
E
Some other island countries that are believed to have no native land mammals in fact had indigenous land mammals at one time.
Whether other island countries also had indigenous land mammals doesn’t affect whether the recently discovered land mammal on New Zealand implies that birds had competition from land mammals.

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LSAT PrepTest 149 Explanations

Section 1 - Logical Reasoning

Section 2 - Reading Comprehension

Section 3 - Logical Reasoning

Section 4 - Logical Reasoning

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