Micro-wear patterns found on the teeth of long-extinct specimens o

Dear experts

Why is option D wrong in question 6?

I understand that option D does not use the logic that Walter used to derive his conclusion. However, as in case of CR, isn't a new information eligible to weaken a conclusion?

In this question, the new information would be Option D (The environment of east Africa at the time australopithecines lived there is found to have been far more varied than is currently thought)

Now, since the passage suggests that new environment can result in variation in tooth micro-wear patterns, why does option D not weaken Walker's conclusion that "australopithecines were frugivores (fruit eaters)" which is based upon his observation regarding the tooth micro-wear characteristics of east African australopithecine.

What if east African australopithecine not chosen by Walker for his observation have different micro-wear patterns, indicating to a different conclusion about their diets?

Thanks!

Can experts guide

(i) how the answer to #5 is D and not E?

(ii) How the answer to #6 is C and not B? The passage says "the diets of current omnivorous primates vary considerably depending on the environments that different groups within a primate species inhabit". So, if micro-wear patterns of australopithecine teeth from regions other than east Africa are analyzed, those micro-wear patterns are likely to be very different from the patterns that Walker found (in East Africa), thereby calling into question Walker's conclusions.

Hi GMATNinja, but in addition, the passage also states that the diets of current omnivorous primates vary considerably depending on the environments that different groups within a primate species inhabit.

So, micro-wear patterns of baboons from "one environment" may indicate absence of hard-bodied insects from the baboons' diet; but that may not necessarily be true from the analysis of micro-wear patterns of baboons from "another environment".

Question 3

The quote you're highlighting only addresses micro-wear patterns that result from baboons eating insects (either soft-bodied or hard-bodied).

Choice (C) goes way beyond this focus on insect consumption. (C) says that micro-wear studies would reveal that there are NO significant differences in tooth micro-wear patterns among baboon populations, as a whole.

There is simply no statement in the passage that suggests this. In fact, in the sentence immediately following the quote you've cited, here's what the author says about "current omnivorous primates" (which by definition would include modern baboons):

"In addition, the diets of current omnivorous primates vary considerably depending on the environments that different groups within a primate species inhabit..."

If the diets of current omnivorous primates vary considerably, then we have even less reason to believe choice (C), because we know that there could be considerable variation in diet among baboon populations.

I hope this helps clarify why we eliminate (C).

Question 1

We can say this in the context of the passage, because the passage never tells us what Szalay thinks about micro-wear characteristics on teeth.

In case the word choice is causing trouble here, let's clarify that enamel is NOT micro-wear, and "heavy enamel" is NOT a micro-wear pattern. Enamel is a protective substance that coats teeth.

So the only thing we do know, according to the passage, is that Szalay suggests that the heavy enamel of australopithecine teeth is an adaptation to bone crunching.

We also know that Walker disputes this suggestion. The citation of micro-wear characteristics is information that Walker, NOT Szalay, uses to support his conclusion that australopithecines were frugivores.

Question 5

The passage states explicitly that modern baboons (described generally) eat ONLY soft-bodied insects rather than hard-bodied insects.

This means that even if modern baboon teeth were sampled across different environments, we would not expect this specific dietary behavior to change. Perhaps there could be some other kind of variation in the diet of different modern baboon populations. But we have no reason to believe this variation would suddenly cancel the author's clear, categorical statement about the types of insects that modern baboons eat as a whole.

That's why choice (D) — which is narrowly focused on what the results would tell us about the absence of some kinds of insects from baboons' diet, would still be most likely to be true of the results obtained.

Question 6

This question is NOT asking, "Which of the answer choices, if true, most weakens Walker's conclusion?"

The question asks us what can be inferred.

So when answering this question, we are not assuming each choice to be true and then asking if that choice would weaken the conclusion.
We are identifying which choice would call Walker's conclusion into question, based on information in the passage itself.

Walker's conclusion is that australopithecines were frugivores. Here's how Walker reaches the conclusion in paragraph one:

• The tooth micro-wear characteristics of east African australopithecine specimens are indistinguishable from those of chimpanzees and orangutans.
• Chimpanzees and orangutans are commonly assumed to be frugivorous primates.
• Therefore, australopithecines were frugivores.

Here's choice (C):


We keep (C) because it directly undermines Walker's logic, as stated in the passage. If orangutans were, in fact, NOT solely frugivorous, but in fact ate a much broader range of foods, then Walker's basis for comparing micro-wear in orangutans to micro-wear in East African australopithecines would be harder to accept.

And here's choice (B):


(B) doesn't tell us anything about what these new micro-wear patterns would show us. Maybe they'd be different from patterns from within east Africa. Maybe they'd be exactly the same. The choice alone doesn't gives us this information, so it doesn't call into question Walker's conclusion about what australopithecines ate.

OjhaShishir claims that "if micro-wear patterns of australopithecine teeth from regions other than east Africa are analyzed, those micro-wear patterns are likely to be very different from the patterns that Walker found (in East Africa)." And both of you refer to this statement, later in the passage:

"In addition, the diets of current omnivorous primates vary considerably depending on the environments that different groups within a primate species inhabit"

The portion quoted only pertains to current omnivorous primates, NOT the long-extinct australopithecines.

Here's where the author actually describes australopithecines:

"if australopithecines were omnivores too, we might expect to find considerable population variation in their tooth micro-wear patterns."

This entire statement is speculation ("IF australopithecines WERE OMNIVORES, we MIGHT EXPECT..."). Even within that speculation, there is no information about variation based on geographic location.

(B) does not directly address the argument that we're trying to call into question, while (C) does. That's why we keep (C) and eliminate (B).

I hope this helps!

the diets of current omnivorous primates vary considerably depending on the environments that different groups within a primate species inhabit;
>>It means diets of CURRENT omnivorous would vary depending on environment in which they live. If a group1 : X type lives in Environment A and group2 of primate species : X type lives in Environment B then their diets would vary and thus Micro-wear patterns on the teeth



>>because species living in same environment then they may have same diet and hence may have same patterns- WHY NOT RIGHT?
Does it mean pattern of group of X type and group of Y type? which is not what mentioned in passage. The passage talks about same types --> different environment --> different patters ( nothing is mentioned about different types in same or different environment)


>> among groups doesn't mean members in groupA, members in group B?
If as above meaning then members of each group should not have different patters but same- then WHY NOT WRONG?
Does it mean among group means : group1 of X , group2 of X, group3 of X not member1 of group1, member2 of group1 etc.?

what i am doing wrong in B and E, please suggest GodGMATNinja GMATNinjaTwo

>> likely can be anywhere between 1% to 99%
so unlikely should be 99% to 1%
likely+unlikely = 100%
then E should not be wrong. please suggest

VeritasKarishma GMATNinja

Why option e is incorrect in question 3
can't we say that environment factor plays role in diet of baboons, for instance, some baboons environment lives in an area where soft-bodied insects found others where hard-bodied.

In question 8
why option C is wrong ?

The only thing the passage tells us is this:
insect eating, which can cause distinct micro-wear patterns, would not cause much tooth abrasion in modern baboons, who eat only soft-bodied insects rather than hard-bodied insects.

That baboons teeth will not reflect the extent to which they eat insects because they eat only soft bodied insects.
No where does it say that other baboons eat hard bodied insects. It tells us that they eat only soft bodied insects.

(D) They would inadequately reflect the extent to which some baboons consume certain types of insects.
(E) They would indicate that baboons in certain regions eat only soft-bodied insects, whereas baboons in other regions eat hard-bodied insects.
Hence, (E) is incorrect and (D) is correct.

As for question 8, the passage does not contrast various explanations for the dietary habits. If it did, it would have something like this:
A ate seeds and nuts because that was the only thing available in that region.
They ate seeds and nuts because they evolved from B who ate seeds and nuts.
They ate seeds and nuts because that was all their body could break down and utilise.
etc...
Hence (C) is incorrect.

1. According to the passage, Walker and Szalay disagree on which of the following points?
“He also disputes Szalay’s suggestion that the heavy enamel of australopithecine teeth is an adaptation to bone crunching, since both seed cracking and bone crunching produce distinctive micro-wear characteristics on teeth.”
(A) The structure and composition of australopithecine teeth
Misreading trap – Walker disputes the S’s suggestion that the heavy enamel (of a. teeth) is an adaption to bone crunching. It’s not about the teeth themselves.
(B) The kinds of conclusions that can be drawn from the micro-wear patterns on australopithecine teeth
It’s not multiple kinds of conclusions. There’s one conclusion (suggestion) that Walker disputes. Also we don’t know if Szalay drew this conclusion from the “micro-wear patterns.” Presumably, based on the verbiage within the passage, he didn’t – “Micro-wear patterns found…may provide evidence about their diets”; this seems to show that this almost new. Maybe Szalay didn’t use it then. Or maybe he did. We don’t know.
(C) The idea that fruit was a part of the australopithecine diet
This is Walker’s conclusion. This isn’t what he disputed with Szalay about.
(D) The extent to which seed cracking and bone crunching produce similar micro-wear patterns on teeth
Misinterpretation/one word off trap – This is more the reason why he disputes something, not what he is actually disputing. Szalay might as well have had another reason as to how he reached the conclusion in which Walker is disputing. Moreover, if anything, the word “similar” is wrong here. Even if the above isn’t necessarily accurate, then they mixed up the wording because the passage says “distinctive micro-wear patterns…”
(E) The function of the heavy enamel on australopithecine teeth
“function” seemed off to me at first. But “function” = “bone crunching”

2. The passage suggests that Walker’s research indicated which of the following about australopithecine teeth?
“His conclusion that australopithecines were frugivores (fruit eaters) is based upon his observation that the tooth micro-wear characteristics of east African australopithecine specimens are indistinguishable from those of chimpanzees and orangutans, which are commonly assumed to be frugivorous primates”
(A) They had micro-wear characteristics indicating that fruit constituted only a small part of their diet.
Opposite; if anything, it would constitute a large part of their diet. They’re frugivores, so presumably they ate a lot of fruit…
(B) They lacked micro-wear characteristics associated with seed eating and bone crunching.
Bingo; “He also DISPUTES Szalay’s suggestion that…a. teeth is an adaption to bone crunching, since both seed cracking and bone crunching produce distinctive microwear characteristic on teeth.” So he saying that the latter adaption isn’t to bone crunching.
(C) They had micro-wear characteristics that differed in certain ways from the micro-wear patterns of chimpanzees and orangutans.
Opposite trap; “the tooth micro-wear characteristics of east African australopithecine specimens are indistinguishable from those of chimpanzees and orangutans” – thus, they didn’t differ in certain ways. They were indistinguishable (AKA the same)
(D) They had micro-wear characteristics suggesting that the diet of australopithecines varied from one region to another.
Opposite trap; the characteristics suggested that the diets were the same (since they had the same type of tooth micro-wear characteristics)
(E) They lacked the micro-wear characteristics distinctive of modern frugivores.
Out of scope; we’re not sure if it’s “modern” frugivores (it just says “east African a. specimens”) AND the “distinctive” portion is just flat out wrong – the tooth micro-wear characteristics of east a. specimens were indistinguishable of other frugivorous primates (frugivores).

3. The passage suggests that which of the following would be true of studies of tooth micro-wear patterns conducted on modern baboons?
“…insect eating, which can cause distinct micro-wear patterns, would not cause much tooth abrasion in modern baboons, who eat only soft-bodied insects rather than hard-bodied insects”
(A) They would inaccurately suggest that some baboons eat more soft-bodied than hard-bodied insects.
Reverse trap – Not necessarily. More specifically, it would show that there would be a diet that consisted of ONLY soft-bodied insects
(B) They would suggest that insects constitute the largest part of some baboons’ diets.
Out of scope – we just know that it would show ONLY soft-bodied rather than hard-bodied. What if they ate other stuff more (but still only ate soft-bodied)?
(C) They would reveal that there are no significant differences in tooth micro-wear patterns among baboon populations.
We know for sure that omnivorous primates have varying diets depending on the environment. If baboons were omnivorous then they would have varying diets and thus varying tooth micro-wear patterns. But we don’t know if they are omnivorous. Moreover, even if they were, this would be the opposite. They would have differences (maybe significant is too strong here) in tooth micro-wear patterns among baboon populations (because they are omnivorous, thus having varying diets, and therefore have differences in tooth micro-wear patterns).
(D) They would inadequately reflect the extent to which some baboons consume certain types of insects.
Bingo. Modern baboons eat ONLY soft-bodied insects (which don’t cause much tooth abrasion). Thus, if there is no distinctive feature to what they eat, then you would have no idea what they eat. If they hard-bodied though, it would be a different story.
(E) They would indicate that baboons in certain regions eat only soft-bodied insects, whereas baboons in other regions eat hard-bodied insects.
Out of scope – the passage is making a broad claim about modern baboons. They eat ONLY soft-bodied insects rather than hard-bodied insects.

4. The passage suggests which of the following about the micro-wear patterns found on the teeth of omnivorous primates?
“…the diets of current omnivorous primates vary considerably depending on the environments that different groups within a primate species inhabit; if australopithecines were omnivores too, we might expect to find considerable population variation in their tooth micro-wear patterns.”
(A) The patterns provide information about what kinds of foods are not eaten by the particular species of primate, but not about the foods actually eaten.
Opposite, if anything. The patterns would show the different environments in which these a’s lived.
(B) The patterns of various primate species living in the same environment resemble one another.
Out of scope; it’s possible, but not required. We know for sure the DIETS will vary depending on the environment, leading to varying micro-wear patterns. But the patterns of various primate species living in the SAME environment doesn’t necessarily have to resemble one another.
(C) The patterns may not provide information about the extent to which a particular species’ diet includes seeds.
Out of scope/story trap – this is way too granular and not supported. It could be seeds but it doesn’t have to. The patterns would show the similar types of diets that may exist within specific groups of primates that live within the same environment.
(D) The patterns provide more information about these primates’ diet than do the tooth micro-wear patterns of primates who are frugivores.
Out of scope trap – we can’t declaratively say this. It’s possible, but not definitively true. All we know for sure if that these primate’s diets vary depending on its environment. It may have these frugivores but not necessarily.
(E) The patterns may differ among groups within a species depending on the environment within which a particular group lives.
Bingo – we know the “diets…vary…depending on the environments that different groups within a primate species inhabit” Thus, this would lead to varying micro-wear patterns for different groups, depending on their environment.

5. It can be inferred from the passage that if studies of tooth micro-wear patterns were conducted on modern baboons, which of the following would most likely be true of the results obtained?
(A) There would be enough abrasion to allow a determination of whether baboons are frugivorous or insectivorous.
Opposite answer – “…insect eating, which can cause distinct micro-wear patterns, would not cause much tooth abrasion in modern baboons, who eat only soft-bodied insects rather than hard-bodied insects.”
(B) The results would suggest that insects constitute the largest part of the baboons’ diet.
Too strong answer – we know that the micro-wear patterns wouldn’t be as present (definitely for the ones who eat soft-bodied insects). But that doesn’t mean the largest part of the
(C) The results would reveal that there are no significant differences in tooth micro-wear patterns from one regional baboon population to another.
Out of scope answer – there is no comparison made between one regional baboon population and another.
(D) The results would provide an accurate indication of the absence of some kinds of insects from the baboons’ diet.
Bingo – it would show that the lack of tooth abrasion = not eating hard-bodied insects (a kind of insect) because the passage flat out says “insect eating, which can cause distinct micro-wear patterns”
(E) The results would be unlikely to provide any indication of what inferences about the australopithecine diet can or cannot be drawn from micro-wear studies.
Opposite answer – it would likely provide an indication; the lack of tooth abrasion would suggest that the diet would not have consisted of hard-bodied insects

6. It can be inferred from the passage that Walker’s conclusion about the australopithecine diet would be called into question under which of the following circumstances?
(A) The tooth enamel of australopithecines is found to be much heavier than that of modern frugivorous primates.
Neutral answer trap; although W disputes S’s suggestion of the heavy enamel being an adaptation to bone crunching, but the comparison within this answer is completely irrelevant. We have no idea what it means if its heavier or not than that of modern frugivorous primates.
(B) The micro-wear patterns of australopithecine teeth from regions other than east Africa are analyzed.
Neutral answer; and what was found from this analysis? Does it show that it is aligned with W? Or does it show that the findings are different?
(C) Orangutans are found to have a much broader diet than is currently recognized.
Bingo; W makes his claim that “tooth micro-wear characteristics of a. specimens are indistinguishable from those of…orangutans” And these orangutans are commonly assumed to be frugivorous primates. Thus, if they actually have a BROADER diet. This would undermine the quote above and even support the contrasted points (of W’s claim) at the bottom.
(D) The environment of east Africa at the time australopithecines lived there is found to have been far more varied than is currently thought.
Neutral answer; HOW was the environment varied? We don’t know anything about the diets. There would have to be some pretty big logical leaps/assumptions to connect the varying environment to the diets.
(E) The area in which the australopithecine specimens were found is discovered to have been very rich in soft-bodied insects during the period when australopithecines lived there.
This wouldn’t weaken the conclusion though. His conclusion is that some similar thing to a. specimens have the same micro-wear characteristics, so thus similar eating patterns (i.e., fruits) as that of the similar thing. The fact that some soft-bodied insects are found isn’t grounds to call into question the conclusion. The conclusion could still be true, regardless of this.

7. The author of the passage mentions the diets of baboons and other living primates most likely in order to
“…research on the diets of contemporary primates suggests that micro-wear studies may have limited utility…. For example, insect eating, which can cause distinct micro-wear patterns, would not cause much tooth abrasion in modern baboons, who eat only soft-bodied insects rather than hard-bodied insects”
(A) provide evidence that refutes Walker’s conclusions about the foods making up the diets of australopithecines
“refutes” is too strong; it means to disprove. The evidence/example that is provided only casts doubt and show the “micro-wear studies MAY have LIMITED utility in determining the foods that are actually eaten.”
(B) suggest that studies of tooth micro-wear patterns are primarily useful for determining the diets of living primates
Opposite; it shows that it’s not that useful since it doesn’t necessarily show it for these “contemporary primates” (AKA living primates)
(C) suggest that australopithecines were probably omnivores rather than frugivores
Similar wording to passage but irrelevant trap; this is for the next example that the passage gives. It does not pertain to the modern primates. This could actually be true, but it is not supported by the passage.
(D) illustrate some of the limitations of using tooth micro-wear patterns to draw definitive conclusions about a group’s diet
Bingo! “…research on the diets of contemporary primates suggests that micro-wear studies may have limited utility…. For example…” then gives the example.
(E) suggest that tooth micro-wear patterns are caused by persistent, as opposed to occasional, consumption of particular foods
Irrelevant/not supported; this is not supported at all! Nothing about frequency.


8. The passage is primarily concerned with
(A) comparing two research methods for determining a species' dietary habits
It’s two different research methods. It’s about the micro-wear pattern stuff not being the most defensible stance.
(B) describing and evaluating conjectures about a species' diet
Conjectures seem a bit too strong. Come back. But conjectures are opinions or conclusions that are drawn from incomplete information. The micro-wear pattern conjecture could be classified as conjecture, given the second paragraph (i.e., insects soft-bodied and diets varying depending on environment).
(C) contrasting several explanations for a species' dietary habits
One word off trap: “Contrasting” is the wrong word here. They’re not “contrasting” anything here. The Walker person just flat out dismisses and disputes the other suggestions/hypotheses. There isn’t a contrast made between each explanation.
(D) discussing a new approach and advocating its use in particular situations
How do we know the micro wear patterns are new? This is not substantiated at all. Moreover, we’re not advocating the approach in particular situations. If anything, we’re saying that it shouldn’t necessarily be used because it doesn’t seem to be super precise.
(E) arguing that a particular research methodology does not contribute useful data
This seems super strong. We know from the first sentence of the paragraph it flat out says the “micro-wear patterns…may provide evidence about their diets.” Although the last paragraph casts some doubt, it doesn’t completely negate the above. This option is way too strong.

Can anyone tell me what is the level of this RC passage
Thanks in advance

Hello PallabiKundu

What I have understand is that you are asking for the difficulty level of the questions. Below it is.

Question #1: 700
Question #2: 600
Question #3: 700
Question #4: 500
Question #5: 700
Question #6: 700
Question #7: 550
Question #8: 700

Overall: 700

GMATNinjaTwo - Dear Sir, Can you please explain wy the answer to below option is B and not E? I could not find this Q discussed above and hence am posting it-

8. The passage is primarily concerned with

(A) comparing two research methods for determining a species' dietary habits>>>>> there are not two research methods, hence wrong
(B) describing and evaluating conjectures about a species' diet????
(C) contrasting several explanations for a species' dietary habits>>>>no explanations as such, hence wrong
(D) discussing a new approach and advocating its use in particular situations>>>>>no new approach discussed, hence wrong
(E) arguing that a particular research methodology does not contribute useful data?????

IMO option E can also be right since in the last statement the Author is saying that the data set needs to be more elaborative... hence implying that this particular research in the passage is not contributing useful data. Hence E.

Thanks in advance.

Hi GMATNinja
I am having a hard time answering the question pertaining to the main point or the primary concern of the author (Q8)

8. The passage is primarily concerned with

(A) comparing two research methods for determining a species' dietary habits
(B) describing and evaluating conjectures about a species' diet
(C) contrasting several explanations for a species' dietary habits
(D) discussing a new approach and advocating its use in particular situations
(E) arguing that a particular research methodology does not contribute useful data

I selected option C and I am not able to see why Bis the correct choice. If you could help me clear my doubts between B and C , that would be great.

Thanks in advance

Bang on! Beautiful explanation for answer choice (E), I got this question alone wrong and was looking for the flaw in my logic. 'Coexisted' doesn't mean 'correlated'!

Thank you GMATNinja !