Critical Reasoning

bblast wrote:Naturalist: The recent claims that the Tasmanian tiger is
not extinct are false. The Tasmanian tiger's
natural habitat was taken over by sheep farming
decades ago, resulting in the animal's systematic
elimination from the area. Since then naturalists
working in the region have discovered no hard
evidence of its survival, such as carcasses or
tracks. In spite of alleged sightings of the animal,
the Tasmanian tiger no longer exists.

Which one of the following is an assumption on which
the naturalist's argument depends?

(A) Sheep farming drove the last Tasmanian tigers
to starvation by chasing them from their
natural habitat. Method is out of scope
(B) Some scavengers in Tasmania are capable of
destroying tiger carcasses without a trace. What about the Tracks?
(C) Every naturalist working in the Tasmanian
tiger's natural habitat has looked systematically
for evidence of the tiger's survival. Strong usage
(D) The Tasmanian tiger did not move and adapt to
a different region in response to the loss of
habitat.
(E) Those who have reported sightings of the
Tasmanian tiger are not experienced naturalists. No idea who is claiming


OA later

mundasingh123 wrote:Hi Whats the source ?

bblast wrote:Naturalist: The recent claims that the Tasmanian tiger is
not extinct are false. The Tasmanian tiger's
natural habitat was taken over by sheep farming
decades ago, resulting in the animal's systematic
elimination from the area. Since then naturalists
working in the region have discovered no hard
evidence of its survival, such as carcasses or
tracks. In spite of alleged sightings of the animal,
the Tasmanian tiger no longer exists.
Which one of the following is an assumption on which
the naturalist's argument depends?

Conclusion - Tasmanian Tigers are extinct since they have been eliminated from the area.

(A) Sheep farming drove the last Tasmanian tigers
to starvation by chasing them from their
natural habitat.

This choice talks about how the tigers might have gone extinct. It bears no support to the conclusion whether the tigers are extinct. Hence Incorrect.


(B) Some scavengers in Tasmania are capable of
destroying tiger carcasses without a trace.

Negate this one. If the scavengers were not capable of destroying the trace, the naturalists would have found it in the area. This contradicts the premise (but not the conclusion) that naturalists haven't found a evidence. Hence Incorrect.


(C) Every naturalist working in the Tasmanian
tiger's natural habitat has looked systematically
for evidence of the tiger's survival.

It tries to disprove a premise (the same one obtained by negation of choice B) and thus is not an assumption. Incorrect. Remember - premise of an argument is a fact and cannot be disputed.

(D) The Tasmanian tiger did not move and adapt to
a different region in response to the loss of
habitat.

Negate this one. Tasmanian tigers did move and adapt to a different region - aha! this would imply that the tigers are alive in a different area, thereby destroying the argument. Thus, it is an assumption. Correct


(E) Those who have reported sightings of the
Tasmanian tiger are not experienced naturalists.

This again tries to disprove a premise, which states for a fact that tigers have not been sighted in the area. Thus incorrect.

OA later

stormier wrote:

bblast wrote:Naturalist: The recent claims that the Tasmanian tiger is
not extinct are false. The Tasmanian tiger's
natural habitat was taken over by sheep farming
decades ago, resulting in the animal's systematic
elimination from the area. Since then naturalists
working in the region have discovered no hard
evidence of its survival, such as carcasses or
tracks. In spite of alleged sightings of the animal,
the Tasmanian tiger no longer exists.
Which one of the following is an assumption on which
the naturalist's argument depends?

Conclusion - Tasmanian Tigers are extinct since they have been eliminated from the area.

(A) Sheep farming drove the last Tasmanian tigers
to starvation by chasing them from their
natural habitat.

This choice talks about how the tigers might have gone extinct. It bears no support to the conclusion whether the tigers are extinct. Hence Incorrect.


(B) Some scavengers in Tasmania are capable of
destroying tiger carcasses without a trace.

Negate this one. If the scavengers were not capable of destroying the trace, the naturalists would have found it in the area. This contradicts the premise (but not the conclusion) that naturalists haven't found a evidence. Hence Incorrect.


(C) Every naturalist working in the Tasmanian
tiger's natural habitat has looked systematically
for evidence of the tiger's survival.

It tries to disprove a premise (the same one obtained by negation of choice B) and thus is not an assumption. Incorrect. Remember - premise of an argument is a fact and cannot be disputed.

(D) The Tasmanian tiger did not move and adapt to
a different region in response to the loss of
habitat.

Negate this one. Tasmanian tigers did move and adapt to a different region - aha! this would imply that the tigers are alive in a different area, thereby destroying the argument. Thus, it is an assumption. Correct


(E) Those who have reported sightings of the
Tasmanian tiger are not experienced naturalists.

This again tries to disprove a premise, which states for a fact that tigers have not been sighted in the area. Thus incorrect.

OA later

stormier wrote:There is. Not discovered implies there was no trace. Did not look systematically implies the trace could be present but wasn't found.

However, this disproves (or raises doubts over) a premise. A premise is always true. In other words, if a premise mentions the sighting of flying pigs it cannot be disputed.

Choice C tries to find a hole in the premise. The question is to find a hole in the link that connects the premise to the conclusion.

mundasingh123 wrote:

stormier wrote:There is. Not discovered implies there was no trace. Did not look systematically implies the trace could be present but wasn't found.

However, this disproves (or raises doubts over) a premise. A premise is always true. In other words, if a premise mentions the sighting of flying pigs it cannot be disputed.

Choice C tries to find a hole in the premise. The question is to find a hole in the link that connects the premise to the conclusion.

I agree with u on the pt that if an option disproves a premise , the choice has to be incorrect.
But My version of "looked systematically" is that the Naturalists didnt follow a step-by-step process which means that this answer choice doubts the effectiveness of the search that the naturalists conducted .Its just that i dont see a conflict between the premise and the choice.