Question 53·Medium·Central Ideas and Details
Isotopic analysis of human remains from the coastal settlement of Cala Verde was undertaken to clarify the inhabitants’ primary food sources. Because the village sat beside a sheltered bay and fishing tools littered the site, archaeologists assumed the community relied mainly on seafood. Yet the carbon isotope ratios revealed that most of the calories consumed came from inland cereal grains obtained through trade with agricultural neighbors.
According to the passage, what did the isotopic analysis reveal about the diet of Cala Verde’s inhabitants?
For questions asking what a passage "reveals" or "states" about a topic, first underline exactly what the question targets (here, the result of isotopic analysis about diet). Then go back to the passage and find the sentence that directly reports that result—often signaled by contrast words like "Yet" or "However." Paraphrase that sentence in your own words and choose the option that says the same thing without adding new details or relying on the initial assumptions described earlier in the passage.
Hints
Focus on results, not assumptions
Make sure you separate what archaeologists assumed from what the isotopic analysis actually revealed about the diet.
Locate the revealing phrase
Look for the sentence that starts with a contrast word like "Yet" and mentions what the carbon isotope ratios "revealed." That sentence directly answers the question.
Ask what “most of the calories” refers to
In that key sentence, pay close attention to the phrase describing where "most of the calories" came from, and then find the answer choice that says the same thing in different words.
Step-by-step Explanation
Understand what the question is asking
The question asks: According to the passage, what did the isotopic analysis reveal about the diet of Cala Verde’s inhabitants?
So you are looking for the result of the isotopic analysis, not the archaeologists’ original assumptions based on location and tools.
Find where the analysis results are described
Scan the passage for where the isotopic analysis is actually discussed.
Near the end, look at the sentence starting with "Yet the carbon isotope ratios revealed that...". This is where the passage directly tells you what the analysis showed about their food sources.
Interpret that key sentence and match it to a choice
The passage says that the carbon isotope ratios "revealed that most of the calories consumed came from inland cereal grains obtained through trade", which contrasts with the earlier assumption that they relied mainly on seafood.
This means their primary calories came from cereal grains, not from seafood. That matches choice A) They obtained the majority of their calories from cereal grains rather than seafood.