Join us for MBA Spotlight – The Top 20 MBA Fair      Schedule of Events | Register

 It is currently 06 Jun 2020, 00:07

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Thirty years after the forests of the Randall Valley were

Author Message
TAGS:

### Hide Tags

Senior Manager
Affiliations: UWC
Joined: 09 May 2012
Posts: 328
GMAT 1: 620 Q42 V33
GMAT 2: 680 Q44 V38
GPA: 3.43
WE: Engineering (Entertainment and Sports)
Thirty years after the forests of the Randall Valley were  [#permalink]

### Show Tags

Updated on: 31 Oct 2013, 11:42
00:00

Difficulty:

5% (low)

Question Stats:

85% (01:25) correct 15% (01:42) wrong based on 280 sessions

### HideShow timer Statistics

Thirty years after the forests of the Randall Valley were destroyed by fire, none of the twelve species of lizards native to the valley remain. Since the absence of trees has increased the average annual temperature in the area by 4 degrees, scientists have hypothesized that the climate change has played a significant role in the disappearance of the lizards.

Which of the following, if true, would most strengthen the scientists' hypothesis?

A. Most of the twelve species of lizards native to the Randall valley were already declining in population thirty years ago.
B. The very same species of lizards can still be found in a neighboring valley, where the destruction of the forests was not accompanied by a rise in temperature.
C. Scientists believe that even if the region can be replanted it will take many generations before the lizards can be reintroduced into the forests.
D. Two of the twelve species of lizard have been on the worldwide endangered species list for fifty years.
E. The loss of the forests also caused a reduction in the population of snails, slugs and worms, the three main sources of food for the lizards.

Originally posted by macjas on 08 Jun 2012, 03:23.
Last edited by Narenn on 31 Oct 2013, 11:42, edited 1 time in total.
Necessary corrections for 'Bumping for review' project
Manager
Status: Rising GMAT Star
Joined: 05 Jun 2012
Posts: 113
Location: Philippines
Concentration: General Management, Finance
GPA: 3.22
WE: Corporate Finance (Consulting)
Re: Thirty years after the forests of the Randall Valley were de  [#permalink]

### Show Tags

08 Jun 2012, 04:36
1
Thirty years after the forests of the Randall Valley were destroyed by fire, none of the twelve species of lizards native to the valley remain. Since the absence of trees has increased the average annual temperature in the area by 4 degrees, scientists have hypothesized that the climate change has played a significant role in the disappearance of the lizards.

Structure:
Premise: After 30 yrs 0/12 lizards remain (no one alive)
Premise: Absence of trees ---> increased temperature
Conclusion: Climate change ----> disappearance of lizards

Which of the following, if true, would most strengthen the scientists' hypothesis?

How do we strengthen an argument? We strengthen an argument by showing that the causation is indeed true (that climate change did cause the disappearance of the lizards). How can we show such causation? We show it by providing evidence.

A. Most of the twelve species of lizards native to the Randall valley were already declining in population thirty years ago. This actually WEAKENS the statement. If this were true then the scientists' hypothesis would be wrong.
B. The very same species of lizards can still be found in a neighboring valley, where the destruction of the forests was not accompanied by a rise in temperature. This is what we want. We are trying to show evidence that causation really holds.
C. Scientists believe that even if the region can be replanted it will take many generations before the lizards can be reintroduced into the forests. Out of scope. Yes, this COULD be true but the question still remains, "does this answer choice affect the conclusion?" Ask that and you'll come into terms that it doesn't.
D. Two of the twelve species of lizard have been on the worldwide endangered species list for fifty years.And so? Again, doesn't answer affect the conclusion.
E. The loss of the forests also caused a reduction in the population of snails, slugs and worms, the three main sources of food for the lizards. Like answer choice (A), this WEAKENS the conclusion. Why do we say this? Remember, one of the ways to weaken an argument is to disrupt the causation by introducing another event. For example, the argument says x causes y. One way to weaken the argument is to introduce z and to say that it, not x, causes y.

Hope I helped.
Manager
Status: I will not stop until i realise my goal which is my dream too
Joined: 25 Feb 2010
Posts: 150
Schools: Johnson '15
Re: Thirty years after the forests of the Randall Valley were de  [#permalink]

### Show Tags

08 Jun 2012, 05:50
macjas wrote:
Thirty years after the forests of the Randall Valley were destroyed by fire, none of the twelve species of lizards native to the valley remain. Since the absence of trees has increased the average annual temperature in the area by 4 degrees, scientists have hypothesized that the climate change has played a significant role in the disappearance of the lizards.

Which of the following, if true, would most strengthen the scientists' hypothesis?

A. Most of the twelve species of lizards native to the Randall valley were already declining in population thirty years ago.
B. The very same species of lizards can still be found in a neighboring valley, where the destruction of the forests was not accompanied by a rise in temperature.
C. Scientists believe that even if the region can be replanted it will take many generations before the lizards can be reintroduced into the forests.
D. Two of the twelve species of lizard have been on the worldwide endangered species list for fifty years.
E. The loss of the forests also caused a reduction in the population of snails, slugs and worms, the three main sources of food for the lizards.

anything that is supporting this conclusion "scientists have hypothesized that the climate change has played a significant role in the disappearance of the lizards" is the answer...

Manager
Joined: 12 Mar 2012
Posts: 90
Location: India
Concentration: Technology, General Management
GMAT Date: 07-23-2012
WE: Programming (Telecommunications)
Re: Thirty years after the forests of the Randall Valley were de  [#permalink]

### Show Tags

08 Jun 2012, 06:19
I also marked B as it strengthen the stimulus by justifying that the rise in temperature was the actual reason for extinction of lizards.
_________________
FOCUS..this is all I need!

Ku-Do!
Retired Moderator
Joined: 23 Jul 2010
Posts: 412
GPA: 3.4
WE: General Management (Non-Profit and Government)
Re: Thirty years after the forests of the Randall Valley were  [#permalink]

### Show Tags

04 Nov 2013, 01:59
1
2
Bumping for review and further discussion*.

Manager
Joined: 04 Nov 2017
Posts: 209
Location: United States
Thirty years after the forests of the Randall Valley were destroyed by  [#permalink]

### Show Tags

18 Dec 2017, 19:22
Thirty years after the forests of the Randall Valley were destroyed by fire, none of the twelve species of lizards native to the valley remain. Since the absence of trees has increased the average annual temperature in the area by 4 degrees, scientists have hypothesized that the climate change has played a significant role in the disappearance of the lizards.

Which of the following, if true, would most strengthen the scientists' hypothesis?

A. Most of the twelve species of lizards native to the Randall valley were already declining in population thirty years ago.
B. The very same species of lizards can still be found in a neighboring valley, where the destruction of the forests was not accompanied by a rise in temperature.
C. Scientists believe that even if the region can be replanted it will take many generations before the lizards can be reintroduced into the forests.
D. Two of the twelve species of lizard have been on the worldwide endangered species list for fifty years.
E. The loss of the forests also caused a reduction in the population of snails, slugs and worms, the three main sources of food for the lizards.
Manager
Joined: 20 Feb 2017
Posts: 117
Location: United States
Re: Thirty years after the forests of the Randall Valley were destroyed by  [#permalink]

### Show Tags

18 Dec 2017, 19:32
Choice C: By mentioning neighboring valley, choice indicates that all other conditions are similar except water and deforestation.
Retired Moderator
Joined: 13 Feb 2015
Posts: 196
Re: Thirty years after the forests of the Randall Valley were  [#permalink]

### Show Tags

18 Dec 2017, 20:06
Merged topics. Please, search before posting questions!
_________________
Retired Moderator
Joined: 13 Feb 2015
Posts: 196
Re: Thirty years after the forests of the Randall Valley were  [#permalink]

### Show Tags

18 Dec 2017, 20:06
Merged topics. Please, search before posting questions!
_________________
Re: Thirty years after the forests of the Randall Valley were   [#permalink] 18 Dec 2017, 20:06