Determining whether a given population of animals constitutes a

(1) The passage is primarily concerned with

In the first paragraph, one way to define/identify species distinction is suggested and three reasons are given explaining why this particular method (way) may not be feasible. In the second paragraph, a different method/concept is suggested that people can use in order to determine ''distinction'' among species. Hence, we can reasonably infer that the main idea of the passage is to highlight two different approaches to determining ''distinction'' among species.

This school of thought is perfectly reflected in (C).

(C) considering two different approaches to identifying biological species

Hence, (C) is the right answer choice.

(2) The author of the passage mentions “groups that live in different places” (in line 21) most probably in order to

if you read the whole sentence that contains this highlighted text, we have "A third problem with the biological species concept is that investigators cannot always determine whether two groups that live in different places are capable of interbreeding". From this entire sentence, we can reasonably infer that the highlighted text is a part of a reason that explains why biological species concept to determine species ''distinction'' may not be feasible. This thought is perfectly reflected in (C)

(C) identify an obstacle to the application of the biological species concept

Hence, (C) is the right answer choice.

(3) With which of the following statements regarding the classification of individual species would the author most likely agree?

In the first line of the second paragraph, we have ''When the biological species concept is difficult to apply, some investigators use phenotype, an organism’s observable characteristics, instead''. This would reflect what (A) mentions perfectly.

(A) Phenotype comparison may help to classify species when application of the biological species concept proves inconclusive.

Hence, (A) is the right answer choice.

(4) Which of the following best describes the function of lines 10-13 [First, mating between groups labeled as different species (hybridization), as often occurs in the canine family, is quite common in nature.]?

If you read the sentence prior to the highlighted sentence of the first paragraph, you can see that the ''three reasons'' that follows this key sentence actually supports the idea/assertion made in this key sentence (where the key sentence is "Yet this idea can be too restrictive"). This is exactly what (B) mentions

(B) It develops a point about the biological species concept made in the previous sentence.

Hence, (B) is the right answer choice.

Passage breakdown

In the first paragraph (P1), the author:

• Introduces a difficulty: how to determine whether a group of animals constitutes a distinct species.
• Discuss one method to address this issue.
• Outlines three problems with this method.

In the second paragraph, the author:

• Introduces a second method.
• Explains how this method could work when the first method fails.

For more on the process of breaking down RC passages, check out this article and our live RC videos.

Explanations for individual questions

• Question 1
  
  • Part 1
  • Part 2
• Question 2
• Question 3
  
  • Part 1
  • Part 2

Why answer choice C is not the right answer. Can anyone explain why B over C?
Which of the following best describes the function of lines 10-13?
A. It elaborates the definition of the biological species concept given in a previous sentence.
B. It develops a point about the biological species concept made in the previous sentence.
C. It states the author???s central point about the biological species concept.
D. It identifies a central assumption underlying the biological species concept.
E. It demonstrates why the biological species concept is invalid.

Thank you Lucy Phuong for that excellent explanation!

I agree this is a good explanation, but why do you say that "Yet this idea can be too restrictive" is a previous sentence?? It's in line 10, so it cannot be a previous sentence in my view.

Many thanks in advance for clarification!

I agree that this is a confusing reference, but the question is trying to highlight the sentence that begins in line 10 and ends in line 13. True, you could argue that the question might be referring to both sentences together, but if you make that assumption, none of the answer choices would be correct! Thus, using process of elimination, choice (B) best describes the function of lines 10-13.

When the biological species concept is difficult to apply, some investigators use phenotype, an (25) organism’s observable characteristics, instead.

i third question answer is . Phenotype comparison may help to classify species when application of the biological species concept proves inconclusive.

Here inconclusive and difficult to apply has been taken for same meaning although it differs.

I rejected the option for the same difference .

can anyone help.
thanks

Consider the second example cited in the first paragraph:

Even though the two populations can interbreed, we would not be able to definitively conclude that we have two species. Thus, although not directly stated in the passage, we can infer that using the biological species concept would prove inconclusive in that case.

Choice (A) is the best answer to the third question.

Hi Experts,
In Q1. The passage is primarily concerned with

A. describing the development of the biological species concept
B. responding to a critique of reproductive compatibility as a criterion for defining a species
C. considering two different approaches to identifying biological species
D. pointing out the advantage of one method of distinguishing related species
E. identifying an obstacle to the classification of biological species

I am confused between B and C.While reading the passage,the focus was on drawbacks of biological species concept (based on reproductive compatibility) and towards the end an alternative was described.So I chose B.
Can anyone explain why this is incorrect ?

Question 1

As for choice (B), the author does present several possible critiques of reproductive compatibility as a criterion for defining a species, but the passage is not concerned with responding to those possible critiques.

Rather, the author presents those drawbacks to illustrate situations in which the biological species concept is difficult to apply. The author then presents an alternative (phenotype) that can be used in such situations. The author does not say that the biological species concept should be abandoned in favor of phenotype. Instead, the author simply notes that some investigators use the latter when the biological species concept is difficult to apply.

The author considers both approaches but is not primarily concerned with defending or rejecting either. So, choice (C) is more appropriate.

I hope that helps!

Hi GMATNinja,
Thanks for your response and it helped me to understand why B) is incorrect.
I agree that the author does not respond to a critique.Just to confirm if it was a response to a critique ,the author would have stated his opinion regarding criticism of this theory,correct ?


Also,for understanding sake,can you confirm the following ?

You mentioned that
The author then presents an alternative (phenotype) that can be used in such situations. The author does not say that the biological species concept should be abandoned in favor of phenotype. Instead, the author simply notes that some investigators use the latter when the biological species concept is difficult to apply.

The author considers both approaches but is not primarily concerned with defending or rejecting either. Thus, choice (C) is more appropriate.


Below are my comments:

But doesn't the author's way of transitioning from the drawbacks of one theory (say theory 1) to a theory (say theory 2) which can resolve the issue in theory 1 without specifying any drawbacks of theory 2 suggest a preference for theory 2 ?

Also,the author's main aim is to Determinine whether a given population of animals
constitutes a distinct species .
At the end he says using theory 2 that
If the distribution of measurements from one group does not overlap with those of another, the two groups might reasonably be considered distinct species.

Doesn't this clearly show that theory 2 is the winner here ?

Thanks,
Saksham.

Hi,

Could anybody help me out with (Book Question: 55)
The author of the passage mentions “groups that live in different places” (in line 21) most probably in order to

A. point out a theoretical inconsistency in the biological species concept
B. offer evidence in support of the biological species concept
C. identify an obstacle to the application of the biological species concept
D. note an instance in which phenotype classification is customarily used
E. describe an alternative to the biological species concept

Although I chose the correct answer, I'm still in doubt about A. Do the words in line 20 '...that investigators cannot always determine whether...' show why this answer choice is incorrect, i.e. the underlined words actually point to an inconsistency in practice, and not in theory?

Thank you

Question 2

jawele, that's right! Choice (A) represents a PRACTICAL challenge. According to the biological species concept, a species is a group of animals that can mate with one another but not with members of a different group. The text in lines 20-21 describes the third problem with this approach. Even though in theory this criteria might help us determine whether two groups belong to the same species, if the groups live in different places, there is no way to determine whether they can interbreed. Thus, even though the criteria might make sense in theory, we cannot practically apply it.

Choice (C) is a better answer.

Even if the author had a preference for "theory 2", choice (B) would not be appropriate. The author PRESENTS criticisms of the biological species concept. RESPONDING to criticisms would involve citing criticisms (made by others) and DEFENDING the biological species concept against those criticisms. For example:

Responding to criticisms that she was weak on crime, the mayor pointed out that crime rates have decreased by 5% every year since she took office.

Furthermore, the author only suggests that theory 2 is "the winner" in certain situations. This does not necessarily imply that the author favors one over the other. For example, Medicine X might be great for lowering cholesterol MOST of the time. However, under certain circumstances, it might be better to prescribe Medicine Y. That doesn't make Y better than X, it just means that Y is better in SOME cases.

Similarly, the author states that theory 2 can be used "when the biological species concept is difficult to apply." This does not suggest that theory 2 is better. It simply suggests that there is an alternative that can be used in situations when the biological species concept is not appropriate (i.e. when the drawbacks described would make it inaccurate).

Regardless, the author is not "responding to a critique" of the biological species concept, so choice (B) should be eliminated.

P1 - An idea is introduced. 3 flaws in that idea are pointed out.
P2 - An alternative of previous idea is described.

(Book Question: 54)
The passage is primarily concerned with

A. describing the development of the biological species concept
B. responding to a critique of reproductive compatibility as a criterion for defining a species
C. considering two different approaches to identifying biological species ----
D. pointing out the advantage of one method of distinguishing related species
E. identifying an obstacle to the classification of biological species
-----------------------------------------------

(Book Question: 55)
The author of the passage mentions “groups that live in different places” (in line 21) most probably in order to
pre-thinking - there is a flaw in concept, that is explained using this line.
A. point out a theoretical inconsistency in the biological species concept
B. offer evidence in support of the biological species concept
C. identify an obstacle to the application of the biological species concept------ correct
D. note an instance in which phenotype classification is customarily used
E. describe an alternative to the biological species concept
----------------------------------------------

(Book Question: 56)
With which of the following statements regarding the classification of individual species would the author most likely agree?

A. Phenotype comparison may help to classify species when application of the biological species concept proves inconclusive. ---- correct

--------------------------------------------

(Book Question: 57)
Which of the following best describes the function of lines 10-13 [First, mating between groups labeled as different species (hybridization), as often occurs in the canine family, is quite common in nature.]?
Pre-thinking : before this line, they gave the definition of a study. but called that idea very restrictive. these lines are defining that restriction.

I first selected B and E. one of them should be answer.
B. It develops a point about the biological species concept made in the previous sentence. --- correct.
E. It demonstrates why the biological species concept is invalid. --- so first study is true for some part, while false for rest. but is it really proving the study wrong. what if this line is true. then are you sure that this is of same group. this is not 100% true choice.

ENEM, maybe this post will help?

hey siddharthfrancis,

The statement B says
B)It demonstrates why the biological species concept is invalid.

According to the author, the idea is too restrictive. From this statement, we can easily infer that this idea carries some value; it doesn't matter how much.
So, the biological species concept is not invalid.