Genetic Homogeneity

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Genetic Homogeneity

by amirhakimi » Tue Nov 12, 2013 7:49 am
Some anthropologists believe that the genetic homogeneity evident in the world's people is the result of a "population bottleneck"-at some time in the past our ancestors suffered an event, greatly reducing their numbers and thus our genetic variation.

(A) at some time in the past our ancestors suffered an event, greatly reducing their numbers
(B) that at some time in the past our ancestors suffered an event that greatly reduced their numbers
(C) that some time in the past our ancestors suffered an event so that their numbers were greatly reduced,
(D) some time in the past our ancestors suffered an event from which their numbers were greatly reduced
(E) some time in the past, that our ancestors suffered an event so as to reduce their numbers greatly,

Answer is B
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by GMATGuruNY » Tue Nov 12, 2013 8:10 am
amirhakimi wrote:Some anthropologists believe that the genetic homogeneity evident in the world's people is the result of a "population bottleneck"-at some time in the past our ancestors suffered an event, greatly reducing their numbers and thus our genetic variation.

(A) at some time in the past our ancestors suffered an event, greatly reducing their numbers
(B) that at some time in the past our ancestors suffered an event that greatly reduced their numbers
(C) that some time in the past our ancestors suffered an event so that their numbers were greatly reduced,
(D) some time in the past our ancestors suffered an event from which their numbers were greatly reduced
(E) some time in the past, that our ancestors suffered an event so as to reduce their numbers greatly,

Answer is B
A COMMA + VERBing modifier is attributed to the SUBJECT of the preceding clause.
In A, reducing seems to refer to our ancestors, implying that OUR ANCESTORS were greatly reducing their numbers.
Not the intended meaning: our ancestors did not reduce their own numbers.
The intended meaning is that an EVENT greatly reduced their numbers.
Eliminate A.

So that (in C) and so as (in E) imply PURPOSE.
The result is a strange meaning: that our ancestors suffered for the PURPOSE of reducing their numbers.
Not the intended meaning.
Eliminate C and E.

In D, which seems to refer to an event, implying that our ancestors' numbers were reduced FROM an event -- a nonsensical meaning.
Eliminate D.

The correct answer is B.
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by guptas » Sat Nov 23, 2013 6:12 pm
1. I looked at if we need "that". My first clue was Believe that. Second was I replaced that with which and the sentence didn't work.

2. C doesn't make sense-meaning vise.

3. B makes sense and it is shorter than C.