Q8 - Measurements of the extent

[zacharymosesdavid]

The stimulus reads:
Measurements of the extent of amino-acid decomposition in fragments of eggshell found at archaeological sites in such places as southern Africa can be used to obtain accurate dates for sites up to 200,000 years old. Because the decomposition is slower in cool climates, the technique can be used to obtain accurate dates for sites almost a million years old in cooler regions.

I got it right, but I picked C only because the other answers were not supported at all by the stimulus. Still, I'm not 100% sure I agree that C is supported to a significant extent by the stimulus. C says that if a site being dated has been subject to large unsuspected climatic fluctuations during the time the eggshell has been at the site, then application of the technique is less likely to yield accurate results. The stimulus gives me cause to believe that how far back sites can be dated depends on whether the climate of the site is cooler or warmer. In addition, we already know that no matter what, the apparent best the technique can do is identify sites up to a million years old. But where do we infer that changes in climate are going to make the technique less accurate or effective? Is it because if a site dates back 500,000 years, but experienced some climatic fluctuations that included bouts of warm weather, the decomposition would have occurred more rapidly, thus negatively impacting the technique's efficacy? I don't know, it just seems like a stretch to, from the stimulus, infer that in order for the technique to be effective, the climate has to be stable. Maybe the word "unsuspected" is what it all hinges on? If so, then climatic fluctuations can be accounted for they're "suspected"? What does that really even mean?

Maybe I'm just being pissy, but I thought this wasn't the brightest question.

[nthakka]

Could somebody go over why (C) is correct and why (D) is not?

My big problem with (C) is that it seems unsupported that climate fluctuations would result in less accurate results, just that the fluctuations may cause the results to be accurate for a lesser period of time, such as 200,000 years compared to a million years. I believe they intend to use "accurate" in the broader sense. If something cannot be predicted back a million years, and instead only 200,000 years, they equivocate this difference as "less accurate". At least, that is the best explanation I can think of.

With (D), I think everything looks good until the last part, "and will thus no longer be suitable for examination by the technique". Maybe they can still put to use the decomposed fragments and examine it.

Is my line of reasoning correct?

[ManhattanPrepLSAT1]

The question asks us to identify a conclusion for which the statements offer the most support. We know the following:

1. a technique measuring amino-acid decomposition can be used to date archeological sites in place like South Africa as far back as 200,000 years.
2. because amino-acid decomposition is slower in cooler climates, this technique can be used to date archeological sites in cool climates as far back as one million years.

Answer choice (C) is supported because the technique relies on the rate of decomposition of amino-acids which are affected by climatic conditions. If the climatic conditions have fluctuated and can not be taken into account, then the rate of decomposition would vary during the climatic fluctuations and so cannot be accounted for during the analysis.

Incorrect Answers
(A) is unsupported. The statements do not suggest where the oldest archeological sites are located. It only discusses the effectiveness of using this technique based on climatic conditions.
(B) is unsupported. We know that this technique is used by measuring amino-acid decomposition in eggshells, but the statements do not suggest that this amino-acid decomposition only occurs in eggshells.
(D) is contradicted by the statements. We know that this technique is suitable in cooler climates for dating archeological sites as far back as one million years.
(E) is unsupported. The statements do not suggest where eggshells are more likely to be found.

[aaronwfrank]

The question asks us to identify a conclusion for which the statements offer the most support. We know the following:

1. a technique measuring amino-acid decomposition can be used to date archeological sites in place like South Africa as far back as 200,000 years.
2. because amino-acid decomposition is slower in cooler climates, this technique can be used to date archeological sites in cool climates as far back as one million years.

Answer choice (C) is supported because the technique relies on the rate of decomposition of amino-acids which are affected by climatic conditions. If the climatic conditions have fluctuated and can not be taken into account, then the rate of decomposition would vary during the climatic fluctuations and so cannot be accounted for during the analysis.

Incorrect Answers
(A) is unsupported. The statements do not suggest where the oldest archeological sites are located. It only discusses the effectiveness of using this technique based on climatic conditions.
(B) is unsupported. We know that this technique is used by measuring amino-acid decomposition in eggshells, but the statements do not suggest that this amino-acid decomposition only occurs in eggshells.
(D) is contradicted by the statements. We know that this technique is suitable in cooler climates for dating archeological sites as far back as one million years.
(E) is unsupported. The statements do not suggest where eggshells are more likely to be found.

D is also wrong because it states 200,000 years and less than one fifth. 200,000 is one fifth of a million so it could not be less than one fifth. If it was less than one quarter, it might be closer to the right answer.

[JinZ551]

The question asks us to identify a conclusion for which the statements offer the most support. We know the following:

D is also wrong because it states 200,000 years and less than one fifth. 200,000 is one fifth of a million so it could not be less than one fifth. If it was less than one quarter, it might be closer to the right answer.

I think we should be careful here.
Though 200,000 is 1/5 of a million, but the "one fifth" in answer choice D refers to the decomposition percentage of amino acids of eggshell. And the stimulus only tells us that the decomposition is slower in cool climates, never tells us the exact amino acids decomposition rates. So I think the "one fifth" here is totally unsupported.

The unsupported assumption it made here is that the amino acids of eggshells in cool climate will be 100% decomposed in a million years and must decompose at constant rate, which we cannot infer from the stimulus.