The stimulus does tell us that the weather affects the decomposition rate, roesttezz:
the decomposition is slower in cool climates
So if there have been large fluctuations in the climate, the rate of decomposition would have been altered, and we might not be able to tell just how old that fragment was. Maybe it's hot now, so we have fast decomposition, but there was a period of time 100,000 years ago that it was really cold for 10,000 years, and the decomposition slowed during that time. Our measurements now would indicate that the site was older than it actually was, because we would not see as much decomposition as we would have if it had been hot the whole time.
In short, if the temperature affects the rate, and the temperature fluctuates, then the rate fluctuates. If the rate fluctuates, that affects our estimate and potentially reduces our accuracy.
Adam M. Tyson
PowerScore LSAT, GRE, ACT and SAT Instructor
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