Q10 - In an experiment designed

[ohthatpatrick]

Question Type:
Explain the Discrepancy

Stimulus Breakdown:
Lightning can produce amino acids if the environment is rich in H and lean in O.
When life began, Earth's atmosphere was rich in O and lean in N at the time.

Answer Anticipation:
GIVEN THAT lightning needs "high H, low O" environment to make amino acids (thereby enabling life) and
GIVEN THAT Earth was "High O, low N" when life started,
HOW COULD IT BE THAT lightning made the first amino acids?

We don't normally try to predict answers on this question type, but it seems possible that amino acids came way before life began. If so, maybe the Earth's atmosphere at that earlier time was set up in the "high H, low O" way that lightning likes.

Correct Answer:
A

Answer Choice Analysis:
(A) Yes, this could work. It explains how there might have been pockets of reducing atmosphere that lightning could have struck, even within an Earthly atmosphere that was NOT conducive to lightning.

(B) This tells us nothing about how lightning could have done its magic in the wrong type of atmosphere.

(C) This tells us nothing about how lightning could have done its magic in the wrong type of atmosphere.

(D) This tells us nothing about how lightning could have done its magic in the wrong type of atmosphere.

(E) This tells us nothing about how lightning could have done its magic in the wrong type of atmosphere.

Takeaway/Pattern: The complexity of the paragraph and question stem make this one tricky. If manage to tease out our task of, "Given that Earth had the wrong type of atmosphere at the time, how did lightning manage to make amino acids?", then (A) is the only answer that seems to provide any sort of explanation for how lightning at that time could have gotten around the incorrect atmosphere problem.

#officialexplanation

[saam.pousht-mashhad]

The stem states
" unless sparks occur in a reducing atmosphere [...] amino acids do not form readily and tend to break apart when they do form."

I was debating between choices (A) and (B). I went with (B) because I reasoned that a lightening could still produce the first amino acids because, as quoted above, in reducing environment amino acids "do not form readily" (readily being the key word). This does not mean no amino acid could ever be produced in that environment, only that it is uncommon. (B) states that, although it is uncommon for an amino acid to form, only one is necessary for life on earth. Therefore, we could see how lightening could have been the result of a the production of the first amino acid.

Please let me know what is wrong in my reasoning. I see how (A) is right, but cannot figure out how this does not work.

[fourfolkspa]

I'm not a tutor, but the way I approached these type of questions is to find the answer that best helps explain the apparent discrepancy in the information provided. In fact, the prompt asks us to find the answer that most helps explain how lightning could have produced the first amino acids. So our answer simply can't explain it, but it also has to do a better job of explaining it than any of the other answers.

From that standpoint, A is the better answer for two reasons:

1) If we assume A, based on the information provided, the discrepancy is pretty well resolved. The meteor created the proper environment for amino acids to solve readily.

2) If we assume B, we still haven't addressed the main question prompt, which is to answer how lightning could have produced the first amino acids. B talks about the relationship between amino acids and life. Even if B is true, the fact that a single amino acid can lead to life doesn't directly explain how lightning could have led to amino acids despite the adverse environmental conditions. That's what the question is asking for, and that is what the answer needs to address. And that's why B is wrong.

[demetri.blaisdell]

Thanks for posting, both of you. I always encourage anyone prepping for the LSAT to answer questions on the forums. They say the best way to learn something is to teach it. So keep it up, Fourfolkspa.

I think your explanation of (B) is good but I would go a little further. The stimulus actually says that "amino acids" (plural) are the building blocks of life. So a close reading seems to preclude the possibility that one amino acid actually began all of life. Even the question stem asks about acids (plural).

The other problem is the one that's already been raised: telling us that one was enough doesn't really tell us how it was created.

One last point: even though the LSAT writes these explain a result questions (and strengthen weaken) saying that they want the answer that is better than the others, in practice they only give us one that will do it. Usually you are either adding assumptions to an answer choice or not clearly understanding the paradox if another answer looks good.

I hope this helps. Thank you both for posting.

Demetri

[ivanau12]

Quick question - why is E wrong?

My problem with A was the "temporarily" part - it says that Amino Acids form readily and won't break apart in a reducing atmosphere, so if the atmosphere in temporary, how can one assume that amino acids will last long enough to build life?

[nancychannc]

Quick question - why is E wrong?

The question stem asks "which of the following, if true, would most help to explain how lightning could have produced the first amino acids on Earth?"

E does not involve lightning producing the first amino acids.

I think even with the possible issue of a temporary reducing atmosphere in A, it's still the best answer choice out of the five...

[joseph.m.kirby]

For this question, (A) is the best answer (and it uses concrete language). First of all, take note that (B) and (E) use "could." More specifically, with (B), we are told that a single amino acid could have been sufficient. However, given the information in the stimulus, if this amino acid isn't in a 'reducing' atmosphere, it would "tend to break apart." So, (B) would not resolve the paradox about how life was able to start. (E) also has this problem. An amino acid could temporarily survive; nevertheless, if there is no reducing atmosphere, the amino acid would inevitably break apart (and no life would result). (C) and (D) are out of scope and don't necessarily address the paradox.

[alandman]

Narrowed this down to A and E and ultimately chose E.

However upon reviewing this question, I clearly see why A is the answer.

The argument gives us 2 conditions that explain how life may have began on earth:

1) There was a spark that produced amino acids and 2) the spark occurred in a reducing atmosphere.

A) supports the argument as it addresses both of these conditions. The meteorite impact (one can infer resulting in a spark) occurred in a reducing atmosphere.

E) Supports only the 1st condition, the initial spark. We don't know, however, whether this spark occurred in a reducing atmosphere.

[patrice.antoine]

I thought (E) was completely weak. Who is to say asteroids had hit Earth at the time life began? In fact, who is to say that amino acids survived? Sure, they COULD....but they also could not. Answer choice (A) in comparison just gets right to the meat of the gap.

[nflamel69]

Honestly the key to this question is the stem. The stem specifically said to explain lightning and amino acids. B is irrelevant because it doesn't concern lightning. E is wrong for the same reason. This is probably one of the most odd explain a discrepancy question I've seen though.

[nthakka]

(B) "COULD HAVE BEEN SUFFICIENT" what if it wasn't sufficient? This is a very vague and weak answer choice.

(E) SOME of these amino acids COULD have survived an asteroid's impact with Earth. So, one amino acid may or may not have survived the impact with Earth. 1) How does this explain why amino acids were present? It's way too weak, and the 'COULD' makes it go either way (i.e. a chance it couldn't have happened). (A) is the best and most supportable answer.

[christyturner02]

Quick question - why is E wrong?

My problem with A was the "temporarily" part - it says that Amino Acids form readily and won't break apart in a reducing atmosphere, so if the atmosphere in temporary, how can one assume that amino acids will last long enough to build life?

"Temporarily" doesn't mean "really quickly"; it means "for a limited time" or "not permanent." That time could be anywhere from one second to hundreds of years, as long as that time ends at some point. This fits in with the statement about scientist's beliefs about the Earth's atmosphere at the time life began; the atmosphere remained long enough for lightning to strike and long enough for amino acids to form and survive.

[pewals13]

One of the tutors on this forum (ohthatpatrick?) suggests that when dealing with explain a result questions one should ask "given_________, why _________?"

Core:

1) Life may have begun as a result of an electrical spark that produced amino acids which are the building blocks of life

2) Amino acids form readily-------->spark occurs in a reducing atmosphere

3) Scientists now believe earth's atmosphere was actually rich in oxygen and lean in nitrogen (we are told to take this as true)

So given that earth did not have a reducing atmosphere how could lightening produced the first amino acids?

Answer choices:

(A) Keep it.

(B) You want to explain how amino acids could have formed in the first place, this explains how an amino acid could have produced life. Remember your question "given that earth had a non-reducing atmosphere how could lightening produced the first amino acids?"

(C) You're only interested in the atmosphere at the time life began

(D) This means the spark was less likely to occur when compared with the present

(E) This does not explain how amino acids could have formed in a non-reducing atmosphere.

[dhlim3]

Doesn't A contradict the stimulus?

The stimulus states that the Earth's atmosphere was not fit for amino acid to be formed at the time life began. Answer A directly contradicts this by stating that the Earth's atmosphere was actually made to fit for amino acid at the time life began. (even though it says temporarily, I thought this was irrelevant because I interpreted the scientists' statement as referring to a single moment on which the life began - instead of a range of time period.

But since the stem asks for the answer that most help to explain the discrepancy, i guess it is the best answer of the five choices given. But if I come across a similar question on the real LSAT, I can see myself wasting a lot of time on it since I'm still not convinced of the justification of answer A.

[ohthatpatrick]

I was going to put up a complete explanation for posterity, since we hadn’t yet, but I think the comments and followups have been excellent (and heck YEAH someone even used my prephrase!). Nice work, everyone.

In response to the “Doesn’t A contradict”, question …

Scientists made a claim about “Earth’s atmosphere”, that is the average chemical composition of the global atmosphere.

(A) is making a claim about “the atmosphere around the impact site”.

So those two ideas don’t contradict, because they’re making claims about different atmospheres. Yes, the atmosphere around the impact site is included in Earth’s atmosphere, but the qualities of the impact site aren’t necessarily mirrored by the qualities of the entire Earth’s atmosphere.

(That sounds like a Part to Whole fallacy!)

The atmosphere around a factory might be especially high in sulfur, but that doesn’t contradict the idea that Earth’s atmosphere is low in sulfur.

Does that make sense?

[andrewgong01]

For "B" though why does it matter for us to link it to the idea of the lightening? I went with "B" because it says a single acid would have been enough. In the passage it never said the Low H High N was 100% needed for the lightening+amino acid formation to occur since it says "do not readily and tend to break apart" (i.e. it does not happen all the time). From that my reasoning was that it is true that this condition is very unlikely to allow it to occur but we only need it to occur once for everything else to start forming.

[ohthatpatrick]

For "B" though why does it matter for us to link it to the idea of the lightening?

Because that's what the question stem asked!

"Which answer would most help to explain how lightning could have produced the first amino acids."

You're not wrong that given the language of stimulus, there is a faint chance that lightning could have still sparked a single amino acid into existence.

It's just a faint chance, given what we were told. Most amino acids can't form in that environment, and most of the tiny leftovers that DO form tend to break apart.

Meanwhile, (A) gives us much higher odds by creating the atmosphere that is actually conducive to amino acids forming.