Logical Reasoning

PT133 · S1 · Q19 Anthropologist: It was formerly

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Anthropologist: It was formerly believed that prehistoric Homo sapiens ancestors of contemporary humans interbred with Neanderthals, but DNA testing of a Neanderthal's remains indicates that this is not the case.

Conclusion

Neanderthals and early-humans did not interbreed.

Evidence

The DNA of a Neanderthal from from back in the day is very different from the DNA of a contemporary human.

Evaluation

This seems like a shady comparison. Neanderthals lived more than 100,000 years ago. We're comparing that DNA to contemporary human DNA?

Is a contemporary human's DNA even that similar to an early-human's DNA? Maybe DNA changes enough over 100,000 years that of course it's very different now, whether they were interbreeding or not.

Goal

The author seems to be assuming that

19.

Which one of the following is an assumption required by the anthropologist's argument?

  1. At least some Neanderthals lived

    Opposite

    If the author thought that N's and early humans did interbreed, he would need to assume that at least some of them lived in proximity of each other. But since she's arguing they didn't interbreed, it wouldn't hurt her argument if no Neanderthals and early humans ever crossed paths.

    6% picked this

  2. DNA testing of remains is

    Opposite

    This answer would hurt her argument, as written. She is relying on a DNA dissimilarity to get to her conclusion, so she wants to trust in and believe the accuracy of the DNA profiles we have of Neanderthals and modern humans.

    1% picked this

  3. Correct

    The DNA of prehistoric Homo

    Why this is right

    This rules out a big objection. If we negate it, we hear the objection that "yes, the DNA of modern humans is very different from that of Neanderthals, but the DNA of early humans was significantly more similar, so maybe they did interbreed!" Stated positively, the author is thinking that we can trust our modern DNA samples of humans to be pretty close to what the DNA of an early human would have been (it would not be significantly different).

    Skill tested: Necessary Assumption · how this choice captures the argument's function is the move to repeat next time.

    77% picked this

  4. Neanderthals and prehistoric Homo sapiens

    Too Strong: completely isolated

    The author is only arguing that early humans didn't interbreed with Neanderthals. She doesn't need to believe that they were geographically isolated. They might have seen each other and just thought, "Nahhhh, that ain't my species. I ain't breeding with that."

    2% picked this

  5. Any similarity in the DNA

    Opposite Logic Too Strong: any, must

    The author is thinking: DNA is not ? didn't interbreed similar This answer is accusing her of thinking: DNA is ? did interbreed similar That's an illegal negation of her reasoning. We could alternatively just hear this answer as way too strong an idea: every single similarity in DNA must be because of interbreeding?

    14% picked this

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