Patterson: Bone flutes dating to the Upper Paleolithic are the earliest evidence for music.
Patterson's Conclusion
Music probably first arose during the Upper Paleolithic period.
Patterson's Evidence
Bone flutes from this U.P. period are the earliest evidence for music.
Garza's Response
The U.P period was unusual for its intensive use of bone.
Stuff made of bone can last forever, so we still dig it up archaeologically. Meanwhile, other common instrument materials like wood do not survive well in dug-up ruins.
Evaluate
It might take us a bit to process what Garza is saying, but it's crucial we understand the point she's making.
The fact that her paragraph started with "But" suggests that she is pushing back against Patterson's notion that "music probably arose during the Upper Paleolithic period".
She isn't proposing a specific alternative period when music arose, but she seems to be questioning how Patterson interprets the evidence.
Since the earliest archaeological evidence of musical instruments we have are bone flutes from this U.P. period, Patterson assumes that this is when music started.
But Garza is saying,
Her idea is kind of an alternate explanation for why the earliest instruments we've found were made of bone. It's not because humans started with bone instruments; it's because only bone instruments would survive from that long ago.
Goal
If we know the typical 8 method answers (analogy, counter/example, ruling out options, implications of logic, distinctions, alternate explanations, overlooked considerations, dubious assumptions), this one seems to feel like calling out a Dubious Assumption or suggesting an Alternate Explanation.
Look for something like, or .