PT11 S3 Passage 3 - River Basin in South America Forum

[SecondWind]

Lines 6-10 say:

"He argued that such diversity could be attributed to the absence of significant fluctuations in climate and physical conditions, without which the extinction of species should be rare."

The part that is screwing me up here is the "without which". What is "which" referring to and how do you know? Is it referring to "the absence of significant fluctuations in climate and physical conditions" or "significant fluctuations in climate and physical conditions."

What I'm getting is that "Without the absence of significant fluctuations in climate and physical conditions the extinction of species should be rare."

What I was to say is that "Without the absence" effectively negates itself out the sentence so it's saying "With Significant fluctuations in climate and physical conditions the extinction of species should be rare." But that doesn't make any sense, and I'm pretty sure it's not correct. I'm thinking it should say "If there are stable conditions then few species should be becoming extinct", but I don't know how to arrive at this answer. This is driving bonkers!

Thanks in advance!

[crazyvix]

Lines 6-10 say:

"He argued that such diversity could be attributed to the absence of significant fluctuations in climate and physical conditions, without which the extinction of species should be rare."

The part that is screwing me up here is the "without which". What is "which" referring to and how do you know? Is it referring to "the absence of significant fluctuations in climate and physical conditions" or "significant fluctuations in climate and physical conditions."

What I'm getting is that "Without the absence of significant fluctuations in climate and physical conditions the extinction of species should be rare."

What I was to say is that "Without the absence" effectively negates itself out the sentence so it's saying "With Significant fluctuations in climate and physical conditions the extinction of species should be rare." But that doesn't make any sense, and I'm pretty sure it's not correct. I'm thinking it should say "If there are stable conditions then few species should be becoming extinct", but I don't know how to arrive at this answer. This is driving bonkers!

Thanks in advance!

It says: such diversity could be attributed to the absence of significant fluctuations in climate and physical conditions, without the significant fluctuations in climate and physical conditions, the extinction of species should be rare.

[SecondWind]

Thanks. I agree with you on that being the correct form. The link below helped me justify that answer to myself from a grammatical perspective.

http://www.quickanddirtytips.com/educat ... sus-that-0