Question 178·200 Super-Hard SAT Reading Questions·Information and Ideas
Archaeologists often identify the earliest domestic dogs through changes in skull and tooth shape. Such criteria, however, track anatomy rather than behavior. At a 9,000-year-old settlement, researchers analyzed stable-isotope profiles in bone collagen from canids, humans, and wild canids from the surrounding region. Three canids buried among the settlement's dwellings had profiles indicating diets rich in millet, a crop cultivated there, and freshwater fish, closely matching the inhabitants' diets. By contrast, regional wild canids mainly consumed terrestrial prey. Yet the skulls and teeth of the three settlement canids remained within the range observed among wild canids. Because bone-collagen profiles reflect diet over extended periods, the findings suggest that _____
Which choice most logically completes the text?
For a Hard inference question, combine all major observations and then compare the scope of the choices. Prefer the conclusion that accounts for the full contrast with cautious wording, and reject choices that turn suggestive evidence into a definitive classification, invent an unsupported sequence of events, or generalize to conditions the passage does not examine.
Hints
Combine both findings
Consider what the long-term dietary similarity indicates and how that evidence contrasts with the canids’ skulls and teeth.
Distinguish association from classification
Ask whether the evidence establishes a sustained relationship, definitively classifies the canids as domestic, or evaluates the general reliability of a research method.
Check the scope of each claim
Treat phrases such as “already,” “only after,” and “even where” as claims that require specific textual support.
Step-by-step Explanation
Interpret the dietary evidence
The bone-collagen profiles reflect diet over an extended period. The settlement canids’ consumption of millet and freshwater fish, combined with their burial among the dwellings, therefore supports a sustained connection to the settlement rather than an isolated encounter.
Compare the anatomical evidence
Despite this connection, the canids’ skulls and teeth remained within the range observed among wild canids. Thus, evidence of sustained association was present even though the usual anatomical markers of domestication were absent.
Choose the appropriately limited inference
The supported conclusion is some sustained human-canid associations may have arisen before canids displayed the anatomical features commonly used to identify domestication. This choice preserves the contrast and uses appropriately cautious language without assigning a definitive classification or making unsupported claims about chronology or other dietary conditions.