Question 147·Hard·Command of Evidence
Paleoecologist Marta Nguyen recently examined charred pine cones preserved in ancient hearths on Isla Roca, a remote island 60 km from the South American mainland. These cones come from Pinus rostrata, a tree species that, according to pollen and fossil records, has never grown naturally on Isla Roca. However, the cones are abundant in hearth layers that date from 800 CE to 1200 CE. Nguyen notes that during this interval the coastal city of Puerto Viejo on the mainland was a major trading hub. Therefore, she proposes that inhabitants of Isla Roca imported P. rostrata cones by boat from forests near Puerto Viejo, using them both as fuel and as a food source.
Which finding, if true, would most strongly support Nguyen’s proposal?
For “Which finding would most strongly support” questions, (1) restate the claim in your own words, including who/where/when and any key mechanism (here: import by boat; use as fuel and food), then (2) pick the choice that provides the most direct, specific, same-time-period evidence for that claim. Prefer physical evidence from the relevant site and layers over broad background facts (like availability on the mainland or general signs of trade).
Hints
Pin down the exact claim
Nguyen isn’t just saying the cones are present—she’s explaining how they got there and how they were used. Identify those two parts.
Prefer direct evidence on Isla Roca
The best support will be something found on Isla Roca (not just on the mainland) that links the cones to human transport or human use.
Weigh “trade exists” vs. “these cones were used”
Some choices may suggest trade or availability in general. The strongest choice will show that these pine products were actually being used in the relevant 800–1200 CE layers.
Step-by-step Explanation
Restate what Nguyen is proposing
Nguyen’s proposal (the bolded part) has two key claims:
- People on Isla Roca imported P. rostrata cones from mainland forests near Puerto Viejo.
- They used the cones as fuel and as a food source.
The strongest supporting finding will connect clearly to these claims, and it should match the 800–1200 CE time window of the hearth layers.
Identify what counts as strong support
The best support would be direct evidence on Isla Roca (not just on the mainland) showing that people were actually using P. rostrata products in the relevant layers. Evidence that only shows (a) trade existed generally, or (b) cones were available on the mainland, is weaker.
Evaluate each option for directness
- Mainland-style pottery in the same deposits suggests contact or trade during 800–1200 CE, but it does not directly connect to P. rostrata cones or their use.
- High cone production near Puerto Viejo could make cones available, but it doesn’t show islanders transported or used them.
- A travel account about merchants carrying pine cones to offshore islands suggests pine cones could be moved by boat, but it still doesn’t show what happened specifically on Isla Roca or whether the cones were used as food.
- The remaining option provides direct physical evidence on Isla Roca tied to the same hearth layers.
Choose the finding that most directly supports the proposal
“Residues of pine-nut oil are detected on ceramic bowls excavated from the same hearth layers on Isla Roca.”
This is strongest because it directly indicates food processing/consumption of pine nuts on Isla Roca in the same dated context as the cones. Given that P. rostrata did not grow naturally on the island, this strongly supports Nguyen’s claim that inhabitants deliberately imported the cones and used them as a food source (and the cones’ presence in hearths aligns with fuel use).