Tough one !

[himu]

Although blue herons can still be found along the Maine coast, their population has declined dramatically when compared to the 1970's, a period in which there were fewer bald eagles competing with them for food and nesting sites.

their population has declined dramatically when compared to the 1970s

their population has declined dramatically compared with the 1970s

their populations have declined dramatically since the 1970s

their populations have declined in comparison to those of the 1970s

their population has declined in comparison with that of the 1970s

[aditya8062]

my take is C

[aditya8062]

E is wrong coz :"that" can refer to only to "population" and not "their population"
so the the option E becomes : their population has declined in comparison with population of the 1970s
hence E as written above gives a very strange meaning

[GMATGuruNY]

Although blue herons can still be found along the Maine coast, their population has declined dramatically when compared to the 1970's, a period in which there were fewer bald eagles competing with them for food and nesting sites.

their population has declined dramatically when compared to the 1970s

their population has declined dramatically compared with the 1970s

their populations have declined dramatically since the 1970s

their populations have declined in comparison to those of the 1970s

their population has declined in comparison with that of the 1970s

In A and B, their population is illogically compared to the 1970s.
APPLES must be compared to APPLES.
A comparison must compare LIKE THINGS.
Eliminate A and B.

D and E change the intended meaning by omitting dramatically.
Since C maintains the intended meaning and is free of errors, eliminate D and E.

The correct answer is C.

[ranjeet75]

[quote="aditya8062"]E is wrong coz :[b]"that" [/b]can refer to only to [b]"population"[/b] and not [b]"their population"[/b]
so the the option [b]E becomes [/b]: [i]their population has declined in comparison with population of the 1970s[/i]
hence E as written above gives a very strange meaning[/quote]

Why "that" can refer to "population" and not to "their population"

[EducationAisle]

The correct idiom would be population in the 1970s and not population of the 1970s.

Basically, the intent is to refer to population of blue herons in the 1970s.

[aditya8062]

@RANJIT

Why "that" can refer to "population" and not to "their population"

RON has said abt this rule many times and i have made a note of it
for example : japan's population is shrinking faster than that of any other nation
here "that" again refers to just japan and not to japan's population [/i]

[ranjeet75]

[quote="aditya8062"]@RANJIT [quote]Why "that" can refer to "population" and not to "their population"[/quote]
RON has said abt this rule many times and i have made a note of it
for example : [i]japan's population is shrinking faster than that of any other nation [/i]
here [b]"that" [/b]again refers to just [b]japan [/b]and not to [b]japan's population[/b] [/i][/quote]

Please quote any link of Ron's explanation. I just want to know the details of the rule.

[Brian@VeritasPrep]

One way to look at this distinction:

"Their population" or "Japan's population" exists with either "Their" or "Japan's" signifying possession (the population belongs to them).

The word "of" in "that of" or "those of" also serves to assign possession. So because "of" is in there, possession now belongs to "the 1970s".

For example, if you were to say "Harvard University's endowment is far greater than that of any other school." "Harvard University's" assigns possession to its endowment, and "that of" assigns possession to the other schools. This sentence DOES NOT mean "Harvard's endowment is the same a Harvard's endowment of any other school". "that of" reassigns possession.

So in the original sentence, "their" is the possession for the first part of the comparison (blue herons) and "that of / those of" is the possession for the second part (the 1970s).


Hope that helps...

[iongmat]

Hello Brian, in view of your comments, can you please see how the following is correct:

One of the primary distinctions between our intelligence and that of other primates may lie not so much in any specific skill as in our ability to extend knowledge gained in one context to new and different ones.

"our intelligence" should also be possessive.

[aditya8062]

One of the primary distinctions between our intelligence and that of other primates may lie not so much in any specific skill as in our ability to extend knowledge gained in one context to new and different ones.

"our intelligence" should also be possessive.

this sentence as it is perfect ."that" is referring to intelligence

[Brian@VeritasPrep]

Hello Brian, in view of your comments, can you please see how the following is correct:

One of the primary distinctions between our intelligence and that of other primates may lie not so much in any specific skill as in our ability to extend knowledge gained in one context to new and different ones.

"our intelligence" should also be possessive.

It is - "our" means "belonging to us". So in this sentence you have two possessives for "intelligence" - "our intelligence" and "that of primates".[/quote]