IMO C.

Whats the OA ?

I will go with A....

I will go with A.

Whereby means "by what or which means". Hence its usage is incorrect here. Use of "in which"defines the theory and that is what is intended in the underlined statement.

B is incorrect: Incorrect use of present tense. Use of past tense is correct.

I will choose C

I found 2 mistake:
"in which" modify "natural selection", not "his therory"
"evolved" should be in present tense

C correct all these error.

OA is "D" . Source : Grockit.

I dont know why it should be "have evolved" here

geekforu wrote:Prompted by observations of seemingly related species in neighboring locales that he made during his five-year voyage around the world on the HMS Beagle, Charles Darwin conceived his theory of natural selection in which all species evolved over time from a single ancestor or very few common ancestors.


A. in which all species evolved over time from a single ancestor or very few common ancestors

B in which all species evolve from a single ancestor or very few common ancestors over time

C whereby over time all species evolve from a single ancestor or very few common ancestors

D whereby all species have evolved over time from a single ancestor or very few common ancestors

E whereby all species evolved over time from a single ancestor or very few common ancestors

in which is wrong here, remember, which is a noun modifier, meaning, the noun and modifier should always touch each other. Here which wrongly refers to selection, it should modify theory. We cannot skip of natural selection considering it is a prepositional phrase. A & B out.
C = evolve - present tense, wrong
D = have evolved = correct, evolution started earlier and still it is going.
E = evolved, past tense is wrong, evolution cannot stop.

D is correct because if u notice A and B option then in both of them "in which" is there and acc to GMAT which should be preceded by a comma and moreover it points to natural selection rather than the theory......................

geekforu wrote:Prompted by observations of seemingly related species in neighboring locales that he made during his five-year voyage around the world on the HMS Beagle, Charles Darwin conceived his theory of natural selection in which all species evolved over time from a single ancestor or very few common ancestors.


A. in which all species evolved over time from a single ancestor or very few common ancestors answer choice

B in which all species evolve from a single ancestor or very few common ancestors over time

C whereby over time all species evolve from a single ancestor or very few common ancestors

D whereby all species have evolved over time from a single ancestor or very few common ancestors

E whereby all species evolved over time from a single ancestor or very few common ancestors

i doubt that the answer you guys posted is D because the tense it used here is past simple so we can eleminate B, C, D
in E and A, "whereby" is not in preference to " in which" thus A is correct

aspirant2011 wrote:D is correct because if u notice A and B option then in both of them "in which" is there and acc to GMAT which should be preceded by a comma and moreover it points to natural selection rather than the theory......................

umm not true on "in which", see og12 sc #70 "Louis Agassiz"

I am also not sure on this because I have also seen few sentences where even if a comma is not preceding "which" then also the sentence in GMAT is correct.....................can anyone let me know the concept when to place a comma before "which"...............

aspirant2011 wrote:I am also not sure on this because I have also seen few sentences where even if a comma is not preceding "which" then also the sentence in GMAT is correct.....................can anyone let me know the concept when to place a comma before "which"...............

Indeed, all instances of which are prceded with a comma on GMAT, exceptwhen 'which' is used in a prepositional phrase. For example, in this case, 'in which' is a prepositional phrase (since it starts with a preposition in) and hence, no comma is required before 'which'. In fact, in such case, comma before which would actually be wrong.

Got a PM for some more clarification on this question.

In this question, the point is not so much about the difference between "in which" and "where". This should be taken as a through and thorough "tense question". Let us take it this way:

Would you say:

(a) Human beings have evolved from monkeys.

Or would you rather say:

(b) Human beings evolved from monkeys.

Perhaps you would agree that (a) is more appropriate. It is called "Present perfect". For one thing, there is nothing to suggest that the process of evolution is over (and hence, "Simple Past", as used in (b) is not the correct usage, since Simple Past is used to depict events that have already finished).

Also, a very clear point of distinction between Present Perfect and Simple Past is that Present Perfect is used when the sentence conveys an event that occurred at an "unspecified time" in the Past; Simple Past is used when an event occurred at a "specific time" in the past.

So, if we look at the following sentences:

(a) Human beings have evolved from monkeys 50,000 years ago.

Or

(b) Human beings evolved from monkeys 50,000 years ago.

In this case, Simple Past (as used in (b)) would be the correct choice, since we are mentioning a "specific time" (50,000 years ago).

In the sentence under consideration, D is the only choice that uses Present Perfect, and is hence, the correct choice.

Ashish,

Thanks for the reply. So basically the take away from this question would be:

Past tense is used when an event has finished or has a specific mention of time period.

Present Perfect tense is used when an event that started in the past and has its impact still in the present or for past events which have no specific mention of a time period.

Please correct me if am wrong.

went with D