Reading Comprehension

PT150 · S1 · P4 · Q27 Evolutionary Implications of Cooking

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It might reasonably have been expected that the adoption of cooking by early humans would not have led to any changes in human digestive anatomy.

Topic

Evolutionary effects on humans of cooking

Framework

Old / New

Main Point

People used to think that humans' use of cooking probably didn't have any effect on digestive anatomy, but now we think we've evolved so much to having a cooked diet (our teeth, jaws, and possibly intestines) that we'd be unable to survive in most cases on a raw food diet.

Summary

FIRST PARAGRAPH

- It might reasonably have been expected that X. After all, Y. However, current evidence suggests ...

These rhetorical features warn us about what the passage will likely be doing. We open with an allusion to Old beliefs, or Typical beliefs, or usual assumptions, and then we get our Author's (but / yet / however / recently) Pivot right after that.

Upon reading the first sentence, we should already be pausing and saying to ourselves,

And we'd be right. That's essentially the main point right there.

From the "However" until the end of the first paragraph, we're getting the current evidence for the fact that cooking has changed us: - we wouldn't be able to live off raw food (except under special circumstances) - this suggests we've now evolved to a form that requires cooked food - there has actually been plenty of time (on an evolutionary scale) for these changes to take place, since we have evidence that cooking started over 250,000 years ago.

The author crystallizes her takeaways at the end of the first paragraph, saying

Because we could cook, we were able to eat a diet with more high caloric density food. Because we were able to eat that type of food, our bodies adapted ways to optimize eating that type of diet, and now we're so adapted to a cooked diet that we'd struggle to live on a raw diet.

SECOND PARAGRAPH

The topic sentence here indicates that this paragraph will be discussing questions about how we've changed, to be more adapted to a cooked diet. - there's a known change in the fossil record to our tooth and jaw size around 100,000 years ago. - the author thinks that was the restul of adapting to cooked food. - she thinks it's possible that cooking started over 1 million years ago and some adaptations occurred then, but then the adaptations seen around 100,00 years ago were ones that happened when we invented the concept of boiling water.

THIRD PARAGRAPH

Since this paragraph begins by saying , it looks like this paragraph still falls under the framing idea at the beginning of the 2nd paragraph: important questions therefore arise

We know that our guts are different from those of other great apes. Some people think it's because we eat more raw meat than apes do. This author thinks that "adaptations to cooking" could just as easily explain it.

She suggests a future research direction in the final sentence, to help determine which hypothesis is more likely.

27.

The authors' primary purpose in the passage is to

describe a scientific puzzle
More than Description
There is a scientific puzzle, as the beginning of the 2nd paragraph suggests: "Important questions therefore arise ..." But the authors aren't just trying to describe it. They're trying to provide some actual answers. If this answer choice said "describe efforts to solve a scientific puzzle" it would seem fair. The fact that the authors of this passage have some conclusions they'd like to offer us makes "describe" too neutral and passive: - Selection for efficient use of high caloric density, we suggest, led to inability to survive on raw food. - Human tooth and jaw size shows signs of decreasing 100k years ago; we suggest that this was a consequence of eating cooked food.
19% picked this
identify a common scientific misconception
Trap
Too Narrow Out of Scope: common scientific This answer seems to address the Challenge a Position (clarify a misconception) type thing going on in the first paragraph, but there are two problems with it as a correct answer: - it's only said that "it might reasonably have been expected" that adopting cooking would not have led to changes in human digestive anatomy. It never identifies that as a "common scientific misconception". It sounds like it could be referring to normal people, not necessarily how the scientific community feels. - this answer would leave out what's going on in paragraph 2 and 3, where we're already past the point of demonstrating the misconception. P1 is arguing we should be thinking that cooking changed human digestive anatomy. And P2 and P3 are exploring the ways in which it may have changed human anatomy.
12% picked this
elucidate the meaning of a
Weaker Match
This answer seems fairly good. The author is definitely discussing the hypothesis that learning to cook changed human digestive anatomy (smaller teeth and jaws, and possibly smaller gut / longer small intestine / smaller colon). To "elucidate the meaning" is to make the meaning of something clear. It's a pretty weird usage to pair up "elucidate the meaning" with "scientific hypothesis". We certainly unpack the implications of a hypothesis (e.g. "if X is true, then that would mean Y and Z.") But that's not the same thing as elucidating the meaning. If I'm elucidating the meaning of "Black Lives Matter", I'm giving fuller context to the slogan, so that the listener understands it's a basic affirmation in response to police brutality that suggests otherwise. If I wrote a passage, though, that was like "Important questions, therefore, arise about how we should combat systemic racism. First of all, should we reallocate money from police departments into social work programs ... ", I'm not really elucidating the meaning of BLM. I'm talking about what its policy implications or goals would be. This answer could be stretched to fit the passage, but when we compare it to the correct answer, that one doesn't require any stretching.
8% picked this
Correct
propose a scientific hypothesis
Why this is right
There is a scientific hypothesis being proposed: learning to cook changed human digestive anatomy (smaller teeth and jaws, and possibly smaller gut / longer small intestine / smaller colon). Proposing this hypothesis captures the spirit of paragraph 1, because we're trying to explain why humans no longer can survive on wild, raw-food diets. The authors end paragraph 1 by saying - Cooking lets humans use diets of high caloric density more efficiently, and selection for efficient use of high caloric density, we suggest, led to inability to survive on raw food. This answer also captures paragraph 2, since the authors continue to refine the hypothesis they're proposing: Human tooth and jaw size shows signs of decreasing 100k years ago; we suggest that this was a consequence of eating cooked food. Paragraph 3, where the authors consider other causal claims that are still too poorly understood to be evaluated, is not really covered by this or any other answer choice. If we asked ourselves, "Why did these authors sit down to write this essay?", it seems reasonable to say that their #1 goal was to communicate the causal story (hypothesis) they have in mind for how cooking changed human digestive anatomy.
Skill tested: Primary Purpose · how this choice captures the passage's function is the move to repeat next time.
56% picked this
undermine the support for a
Out of Scope: Scientific Principle
The authors do undermine a widespread assumption and a reasonable expectation in paragraph 1, but we never name a "scientific principle" that they're going against.
4% picked this

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