Q18 - A high-calorie diet providing

[brandonbodie]

I cannot wrap my head around how answer choice (E) is correct. I changed my answer to (C) right before time was called (thanks virtual proctor!), but now that I'm reviewing #18, none of these answer choices seem ideal.

Is (E) indicating that if shore residents expended more calories proportionally to residents of other environments, there would be fewer calories dedicated to the evolution of the brain? That seems like solid logic, but how can we know that the ancestors from other environments did consume enough calories for the evolution to take place? Is that simply inferred from the fact that the human brain's evolution took place almost exclusively in these other areas?

Thanks!
Brandon

[bbirdwell]

how can we know that the ancestors from other environments did consume enough calories for the evolution to take place? Is that simply inferred from the fact that the human brain's evolution took place almost exclusively in these other areas?

Yes.

Tough question. Remember fundamentals. First, isolate the two conflicting facts.

1. resources needed for brain evolution were MOST ABUNDANT in shore environments

2. brain evolution took place almost exclusively in savanna and woodlands

Here, there is also a third fact that helps give us context for the "conflicting" facts: we need a high-calorie diet.

The big question we need to answer, then, is why did brain evolution NOT take place where resources were MOST abundant?

(E) helps answer this question. It takes many more calories to find food in the shore environments! While this not exactly a "home-run" answer, it makes it more understandable that brain evolution didn't take place where resources were most abundant -- there was more fuel available, but it took more fuel to get it, so the two kind of cancel each other out.

(A) doesn't tell us anything about the environments
(B) doesn't tell us anything about the environments
(C) tempting answer! But original discussion was already about those early times. Today's status is irrelevant. Also, notice that this would not explain why the shore environments, where resources were MOST abundant, were not utilized. That's the burning question. Why NOT the shore environments?
(D) irrelevant

Hope that helps!

[griffin.811]

So its also important to keep in mind that we don't know how much more abundant these resources were in the shore regions.
What if there was just one more piece of fatty food in the shore regions, but it took more energy/calories to extract the food sources in this region than in the pains that that had less of an abundance of fatty food, yet still had a more tthan sufficient fatty food supply AND that supply was readily and easily accessable, people may not have even lived in the shore regions for evolution to have taken place there

[lhermary]

This was such a hard question. I picked (C), but I understand now why it is wrong. (E) seems to be the best of out of absolutely putrid answer choices.

[bp0]

In my opinion a is just as strong here. You could say mayb they started outin the woods and because of a never had to leave in the first place! So basically in my opinion it then comes down to subjectivity in which answer is essentially stronger . . . .

[ttunden]

can anyone else explain why A is wrong? if the metabolic rate is much lower, then that means they are not burning that many calories

This could explain why evolution took place almost exclusively in woodland/savanna areas as opposed to shore. So even though the savanna/woodland areas have less food resources than shore environment does, answer choice A explains why the evolution of the brain could take place in the woodland area.

I was deciding between A and E during the test.

I just didn't like how E said other environments. How do we know Savanna/woodland is included in that category. What if savanna/woodland is in the same category as Shore for answer E?
are we just assuming that other environments = encompass ALL other environments thus including savanna/woodland areas?

Please help Manhattan Staff

[ohthatpatrick]

Given that:
the shore was the most abundant and reliable source of food resources

Why is it that:
the human brain got its high-calorie diet elsewhere (in savanna and woodland areas)?

Can we say
(A) Because, early humans had a lower metabolic rate than modern humans?

What the heck does early vs. modern have to do with anything? The paradox we're trying to explain only has to do with early humans. It has nothing to do with modern humans.

Our paradox is wondering why early humans seemed to choose savanna/woodland vs. shore.

As you stated, (A) could give us a story that might make us see a way that early humans could have survived on the lower-resource environments of savanna/woodland, but it doesn't give us a reason why early humans would have chosen to do so.

A previous poster said, "What if they started out in savanna/woodland areas?" Sure, that could potentially be a reason they would choose to stay some place with sufficient resources, rather than move towards the shore (just because it has MORE resources).

But we're not allowed to just introduce the idea that they started out in savanna/woodland areas. THAT would be a correct answer, if they told us something like that. Be careful about adding parts to the story that are "implausible, incompatible, or superfluous" (this is the language at the beginning of every LR section). The superfluous and implausible ones are the ones we're most guilty of considering, mostly because we get used to pondering exotic counterexamples when we get into LSAT brain. The correct answer choice here needs to suggest a reason IN FAVOR of savanna/woodland or AGAINST shore, or both.

(E) gives us a reason AGAINST shore. When they say "shore environments" vs. "other environments", we know that "other environments" = "not-shore" = includes savanna and woodland.

And (E) is strongly worded so it has good explanatory strength. Something strongly AGAINST living in shore environment is that gathering food requires [b]significantly[b] greater expenditures of calories than alternative environments.

And again, returning to (A), your desire for this correct answer should be WHY they did something, not HOW it might be possible.

Hope this helps.

[pewals13]

One other point on (A):

I think it can be helpful to judge each answer in its least persuasive light.

(A) This is a relative relationship with a group (modern humans) that is not mentioned in the stimulus. This could mean that early humans had a very efficient metabolism or an inefficient metabolism, you can't get a baseline for modern humans without relying on out of scope knowledge.

Also, even if you were to assume that the answer indicates early humans had significantly more efficient metabolisms this doesn't account for why early humans with a diet of fewer calories were the ones who experienced brain evolution.

If both groups had very efficient metabolisms shouldn't they at least both experience evolution? Why was the group with the fewer calories the only group to experience it?

(E) unambiguously gets at a distinction that could account for the difference in evolution

[Misti Duvall]

Question Type:
Explain a Result

Stimulus Breakdown:
The evolution of the modern human brain that began with our anscestors required a high-calorie diet. Those resources were most abundant to early humans along the shore. But the evolution occured in savanna and woodland areas.

Answer Anticipation:
We need to accept everything in the stimulus for Explain a Result questions as true, then ask: what is weird? Here what's weird is that resources for a high-calorie diet were more abundant along the shore, but our ancestors evolved in savannas/woodlands instead. All we need is an answer that CAN explain this weirdness.

Correct answer:
(E)

Answer choice analysis:
(A) Careful. While the stimulus name checks the modern human brain, it's only in reference to its evolution. And what's weird has to do with the evoluation of our ancestors. So any comparison with modern day is irrelevant.

(B) Eliminate for the same reason.

(C) Eliminate for the same reason.

(D) Ok, but recently developed is still developed. And be careful with anything that would call the information in the stimulus into question. Accept it and look for an answer that explains the weirdness. This doesn't.

(E) This does. We just need an explanation for why our ancestors didn't benefit from the abundant resources along the shore. If they would have had to expend lots more calories getting them, that would counteract the benefit of the high-calorie food. So even though savanna/woodland resources may have been less high-calorie, expending less resources to get them could have resulted in a higher calorie intake overall.

Takeaway/Pattern:
Accept the information given in the stimulus, note what is weird, and look for an answer that explains the weirdness.

#officialexplanation