Mechanisms for recognizing kin are found throughout the plant and anim

Question

Mechanisms for recognizing kin are found throughout the plant and animal kingdoms, regardless of an organism’s social or mental complexity. Improvements in the general understanding of these mechanisms have turned some biologists’ attention to the question of why kin recognition occurs at all. One response to this question is offered by the inclusive fitness theory, which was developed in the 1960s. The theory is based on the realization that an organism transmits its genetic attributes to succeeding generations not solely through its offspring, but more generally through all of its close relatives. Whereas the traditional view of evolution held that natural selection favors the continued genetic representation of individuals within a species that produce the greatest number of offspring, the inclusive fitness theory posits that natural selection similarly favors organisms that help their relatives, because doing so also increases their own total genetic representation. The theory has helped to explain previously mysterious phenomena, including the evolution of social insect species like the honeybee, most of whose members do not produce offspring and exist only to nurture relatives.

Inclusive fitness theory has also been applied usefully to new findings concerning cannibalism within animal species. Based on the theory, cannibals should have evolved to avoid eating their own kin because of the obvious genetic costs of such a practice. Spade-foot toad tadpoles provide an illustration. Biologists have found that all tadpoles of that species begin life as omnivores, feeding mainly on organic debris in their soon-to-be-dry pool in the desert, but that occasionally one tadpole eats another or eats a freshwater shrimp. This event can trigger changes in the tadpole’s physiology and dietary preference, causing the tadpole to become larger and exclusively carnivorous, feasting on other animals including members of its own species. Yet the cannibals have a procedure of discrimination whereby they nip at other tadpoles, eating non-siblings but releasing siblings unharmed. This suggests that the inclusive fitness theory offers at least a partial answer to why kin recognition develops. Interestingly, a cannibal tadpole is less likely to avoid eating kin when it becomes very hungry, apparently putting its own unique genetic makeup ahead of its siblings’.

But there may be other reasons why organisms recognize kin. For example, it has recently been found that tiger salamander larvae, also either omnivorous or cannibalistic, are plagued in nature by a deadly bacterium. Furthermore, it was determined that cannibal larvae are especially likely to be infected by eating diseased species members. The fact that this bacterium is more deadly when it comes from a close relative with a similar immune system suggests that natural selection may favor cannibals that avoid such pathogens by not eating kin. For tiger salamanders then, kin recognition can be explained simply as a means by which an organism preserves its own life, not as a means to aid in relatives’ survival.   1 
 Answer: A
Structural keywords can often provide a pretty
accurate basis for answering Main Point questions in
passages without a strong author opinion.
There’s no strong author opinion here, so the answer
to the Main Point is going to be equally neutral. The
passage begins with an introduction of a theory that
“posits” (line 17) that kin recognition developed to aid
an organism’s total genetic representation. The theory
is then applied to honeybees (lines 20–24) and
tadpoles (Paragraph 2). The “but” in line 48 really
drives home the final point—the inclusive theory can’t
explain everything (particularly not the salamander
larvae). So, we want an answer that expresses the
theory properly and shows how it can apply, but not
always. (A) is a per fect fit. This answer accurately
describes the inclusive fitness theory, mentions the
supporting examples, and (most importantly) mentions
the fact that it doesn’t necessarily explain everything.
For the record:
(B) Outside the Scope. This passage doesn’t actually
discuss the mechanisms used to recognize kin. It only
discusses the reasons for kin recognition.
(C) 180. Actually, this is contrary to the facts. The
salamander research would more likely support any
potential hypothesis of traditional evolutionists (as
described in lines 13–16). They feel that natural
selection favors individual organisms—which might
explain why salamanders are only looking out for
themselves. The salamander research runs contrast to
the inclusive fitness theory, which posits natural
section favoring an organism’s total genetic
representation (including family).
(D) FUD. While this may be accurate, it focuses too
much on the salamander research and the traditional
theory of natural selection. It completely ignores the
inclusive fitness theory, which is the primary focus of
the entire passage.
(E) Extreme. The third paragraph alone shows that the
inclusive fitness theory does not (as this answer
states) fully explain kin recognition. 
 1. Which one of the following most accurately expresses the main point of the passage?

(A) Some findings support the hypothesis that kin recognition emerged through natural selection because it increased organisms’ total genetic representation, but this hypothesis may not explain all instances of kin recognition.
(B) Current research supports the view that the mechanisms enabling the members of a species to recognize close relatives are as various as the purposes served by that ability.
(C) Recent research involving tiger salamanders undermines the hypothesis concerning the purpose of kin recognition that is espoused by traditional evolutionary theorists.
(D) New research involving tiger salamanders indicates that the traditional theory of natural selection is more strongly supported by the evidence than is thought by those who consider only the case of the spade foot toad tadpole.
(E) While traditional evolutionary theory was unable to account for the phenomenon of kin recognition, this phenomenon is fully explained by the inclusive fitness theory.

2  
 Answer: C
In heavily detailed passages, try not to answer
questions based on memory because wrong answers
will usually include misapplied details.
Spadefoot tadpoles are described throughout the
second paragraph. There’s a lot of information, so
predicting the answer may not be feasible. Instead,
let’s go through the answers and research only the
likely candidates.
(A) Doesn’t seem familiar. Lines 39–42 suggest that
they can dif ferentiate between siblings and
nonsiblings, but there’s nothing stated about
recognizing other carnivores. Eliminate.
(B) Lines 37–39 describe how tadpoles can grow to
become exclusively carnivorous, but there’s nothing
about the tadpoles being selective about eating
carnivores versus omnivores. Eliminate.
(C) According to lines 35–38, the eating of another
tadpole can change a tadpole’s dietary habits (turning
it carnivorous), which causes the tadpole to become
larger. That detail about a change in body size makes
this answer a match. For the record:
(D) This is the complete opposite. The behavior of the
tadpoles is mentioned as direct support for the
inclusive fitness theory.
(E) A slight distortion. It’s not the carnivorousness that
develops to protect the evolutionary success of the
species. It’s the ability to recognize kin that develops
to protect the species. 
 2. The passage states which one of the following about some spadefoot toad tadpoles? \

(A) They develop the ability to recognize fellow carnivores.
(B) They feed only upon omnivorous tadpoles.
(C) They change in body size when they become carnivores.
(D) Their carnivorousness constitutes an important piece of evidence that calls into question the inclusive fitness theory.
(E) Their carnivorousness would not occur unless it contributed in some way to the evolutionary success of the spadefoot toad species.

3  
 Answer: D
In detail-oriented passages, answers to questions
about the author’s opinion will most likely be found
around major keywords.
According to the author, the inclusive fitness theory “has
helped to explain” (line 20) and can be “applied usefully
to” (lines 25–26) some instances of kin recognition.
“But” (line 48), there may be other explanations for kin
recognition. That’s (D). For the record:
(A) Quite the opposite. According to the first
paragraph, understanding of mechanisms has
increased despite a lack of explanation for why kin
recognition occurs.
(B) Again, opposite of what the author states.
Lines 12–19 directly show how the inclusive fitness
theory runs in contrast to the traditional evolutionary
theory.
(C) There is no suggestion on the author’s part that
theories need to ignore any characteristics of any
organisms.
(E) The author doesn’t mention any current theories
outside of the inclusive fitness theory. However, by
vir tue of the last paragraph conflicting with the
inclusive fitness theory, it’s evident that the author
would not find that theory to be the most successful. 
 3. Based on the passage, the author would be most likely to agree with which one of the following statements about evolutionary explanations of kin recognition?

(A) It is impossible to understand the mechanisms underlying kin recognition until an evolutionary explanation of such recognition has been attained.
(B) Such explanations require no modifications to traditional evolutionary theory.
(C) For any such explanation to be fully adequate it should ignore the differences of social or mental complexity of the organisms whose abilities it is intended to explain. 
(D) Kin recognition may have different evolutionary explanations in different species. 
(E) No other evolutionary explanation can account for the wide diversity of unusual phenomena with the same success as the inclusive fitness theory.

4  
 Answer: A
When a sentence is presented in contrast to previous
sentences, expect a wrong answer to be completely
opposite of what you’re looking for.
To understand the function of the last sentence of the
second paragraph, you need to remember the function
of everything that came before it. The bulk of the
second paragraph was about the tadpoles that avoided
eating siblings in order to improve the survival of their
genetic lineage. This example was provided in support
of the inclusive fitness theory. However, the last
sentence begins with “interestingly,” suggesting that
not all is as it seems. Sure enough, just as we’re being
led to believe that tadpoles would spare family
members to protect the genes, we learn that some
tadpoles will eat their siblings after all—so as not to
die from hunger. So, the Purpose seems to provide an
instance that goes contrary to the other evidence,
making the inclusive fitness theory seem inapplicable
in certain cases. Scan the answer choices for a match:
(A) This seems like a good candidate. Just as we were
being lulled into believing that the inclusive fitness
theory was a winner, along comes this fact that throws
a monkey wrench into the system. This is a match to
our prediction. For the record:
(B) Outside the Scope. The fact in the last sentence is
referring only to the spadefoot toad tadpoles, and
makes no comparison to other species.
(C) 180. This “interesting” note runs contrary to
everything that came before it.
(D) Extreme. While it may question the validity of the
inclusive fitness theory, it doesn’t necessarily make
the tadpoles’ behavior unexplainable. In fact, it is
explained—they’re ver y hungr y and are more
interested in saving themselves.
(E) 180. The information that precedes the last
sentence is not less relevant. It’s plenty relevant as
support for why the inclusive fitness theory is plausible. 
 4. Which one of the following most accurately describes the function of the last sentence of the second paragraph?

(A) to draw attention to behavior that further complicates the set of facts to be explained by any theory of natural selection that accounts for kin recognition
(B) to explain why cannibals in most species eat their kin less often than do cannibal spadefoot toad tadpoles
(C) to describe behavior that lends support to the account of kin recognition presented in the second paragraph
(D) to offer evidence that the behavior of cannibal spadefoot toad tadpoles is unexplainable
(E) to imply that the described behavior is more relevant to the issue at hand than is the immediately preceding material

5  
 Answer: A
Beware of answer choices that discuss information
Outside the Scope of the passage.
The mechanism of a tadpole for recognizing kin is
described in lines 39–42. It involves nipping at other
tadpoles to determine whether they are siblings or not.
(A) is definitely supported by the information in the
passage. Nipping on other tadpoles is not a visual act,
so the mechanism seems to be at least partially based
on taste or touch. For the record:
(B) Outside the Scope. We know this is the behavior of
cannibalistic tadpoles, but we don’t know what
noncannibalistic tadpoles do. For all we know, they may
nip at other tadpoles, too. In fact, according to the
passage, tadpoles can become cannibalistic after first
accidentally eating another tadpole. So, it doesn’t
seem much of a stretch to consider that some
noncarnivorous tadpoles might also nip other tadpoles.
(C) Outside the Scope. Based on the last sentence, we
know that tadpoles will still eat siblings in extreme
circumstance. However, that’s not because the
mechanism doesn’t work—it’s because of hunger.
There’s no support for this.
(D) 180. The tadpoles utilize this mechanism after
changing physiologically and becoming carnivorous.
(E) 180. Line 32 states that all of these tadpoles start
life as omnivores. Furthermore, we don’t have any
information about other species beyond the tadpoles,
so we can’t infer this. 
 5. The passage most strongly supports which one of the following statements about the mechanism by which cannibal spadefoot toad tadpoles recognize their kin?

(A) It is not dependent solely on the use of visual cues.
(B) It is neither utilized nor possessed by those tadpoles that do not become cannibalistic.
(C) It does not always allow a tadpole to distinguish its siblings from tadpoles that are not siblings.
(D) It is rendered unnecessary by physiological changes accompanying the dietary shift from omnivorousness to carnivorousness. 
(E) It could not have developed in a species in which all members are omnivorous.

6  
 Answer: B
Answers that incorporate figures and dates often
misapply that information. Be wary of these answers.
Most of the passage involves theories to explain kin
recognition. Mechanisms are mostly discussed early in
the first paragraph. In fact, the answer to this question is
clearly presented in lines 4–7: Improvements in
understanding these mechanisms have led to questions
about why they occur. That’s (B). For the record:
(A) Outside the Scope. The first sentence says that
mechanisms exist throughout the animal kingdom,
regardless of complexity. However, that doesn’t mean
that we should assume they have a similar purpose in
all species. In fact, by the two examples in the second
and third paragraph, we get the sense that
mechanisms can serve multiple purposes.
(C) FUD. Some people might be tempted by this
because it uses “1960s” from the passage. However,
the 1960s is only when the inclusive fitness theory
was developed. For all we know, there were many other
theories developed long before the 1960s.
(D) Outside the Scope. While the passage may suggest
that we still don’t have a full explanation of their
purpose, the author never states that this is because
we need more understanding of the mechanisms.
(E) Outside the Scope. While the passage may discuss
different purposes for the mechanisms, there’s no
description of how similar or different the mechanisms
operate. 
 6. The passage states which one of the following about the mechanisms that enable organisms to recognize their close genetic relatives?

(A) The mechanisms are most easily explained if we assume that they have a similar purpose in all species regardless of the species’ social or mental complexities.
(B) The mechanisms have become more clearly understood, prompting interest in the purpose they serve.
(C) The mechanisms have become the focus of theoretical attention only since the 1960s.
(D) The detailed workings of these mechanisms must be better understood before their purpose can be fully explained.
(E) The mechanisms operate differently in different species even when they serve exactly the same function.

7  
 Answer: E
Taking note of where all examples appear, even
seemingly minor ones, can save research time when
questions ask about them.
The honeybees were mentioned at the end of the first
paragraph. According to the paragraph, the honeybees’
behavior of nur turing relatives was “previously
mysterious,” but the inclusive fitness theory helped
explain it. We want an answer choice that’s consistent
with this prediction.
(A) The behavior was known, it was just unexplained.
Eliminate.
(B) There’s no discussion of this kind of reciprocal
nurturing. Eliminate.
(C) While the new theory helps to explain this behavior,
the behavior was simply described as previously
mysterious. This suggests the behavior was merely an
enigma and not necessarily a catalyst for dismissing
traditional theory. Eliminate.
(D) is a grand distortion. The inclusive fitness theory
(which helps explain the honeybees’ behavior) still
states that evolution proceeds by natural selection—
just in a different way from what traditional theories
state. Eliminate.
(E) is a match. It was mysterious under traditional
theories, so some supplement (in this case, the
inclusive fitness theory) was needed to dispel some of
the mystery. 
 7. The information in the passage most strongly suggests that the fact that most honeybees exist only to nurture relatives

(A) was not known to be true before the 1960s 
(B) can be explained only if we assume that these members are in turn nurtured by the relatives they nurture
(C) is what led most biologists to reject the traditional view of evolution
(D) calls into question the view that evolution proceeds by natural selection
(E) is difficult to explain without at least supplementing the traditional view of evolution with further explanatory hypotheses

8  
 Answer: C
Classic ways of weakening arguments in Logical
Reasoning will work equally effectively in Reading
Comprehension Logic Reasoning questions.
In the last sentence, the author concludes that kin
recognition in tiger salamanders can be explained as a
means for preserving their own life and not as a means
for aiding their relatives’ survival. While the evidence
regarding the deadly bacterium definitely supports kin
recognition being used to preserve the individual, there
is no evidence to say that kin recognition is not used
to aid relatives’ survival. The author ignores the
possibility that kin recognition may serve to protect
oneself and one’s relatives. To weaken the claim, the
correct answer choice will show a way that a tiger
salamander would use kin recognition to protect
someone other than itself.
(A) This has no relevance to the argument. What’s
impor tant is not whether the disease af fects
cannibalistic or noncannibalistic salamanders, but
whether or not it affects kin and kin recognition.
Eliminate.
(B) This discusses what makes salamanders
carnivorous or omnivorous, but it has no bearing on
why salamanders recognize kin. Eliminate.
(C) gives us a fact that would weaken the author’s claim.
If this were true, then kin recognition would provide a way
for salamanders to protect their offspring—thus making
kin recognition valuable beyond survival of the individual.
By protecting potential family, this weakens the author’s
claim that kin recognition is simply a self-serving device.
For the record:
(D) This answer misapplies some information from the
first paragraph about the number of offspring (part of
traditional evolutionary views). However, once again,
the number of offspring a salamander has is not
directly relevant to the reason for being able to
recognize kin.
(E) Even if this were true, according to the passage,
they’re still immune to the one deadly bacterium that’s
mentioned. And, because that particular bacterium is
more deadly when consumed through kin, the greater
immunity to other diseases isn’t necessarily relevant to
kin recognition.
It’s good to note for this question that the correct answer
is the only one that focuses on kin recognition, the Topic
of the argument the question asks us to weaken. 
 8. Which one of the following would, if true, most help to undermine the author’s evaluation in the last sentence of the passage? 
(A) Many tiger salamander larvae infected by the deadly bacterium are not cannibalistic. 
(B) The factor that determines which tiger salamander larvae are carnivorous and which are omnivorous is not contained in the genetic makeup of the larvae.
(C) Kin recognition helps tiger salamanders avoid inbreeding that may be life-threatening to their offspring.
(D) Noncannibalistic tiger salamanders tend to produce fewer offspring than cannibalistic tiger salamanders.
(E) Cannibalistic tiger salamanders are immune to certain diseases to which noncannibalistic salamanders are not.

Source:   LSAT Official PrepTest 56   
 Difficulty Level:   700

PUNEETSCHDV · Answer

i took 18 minutes and for eight ques i guess not bad

my answers and explanations :

1 A some findings support that two examples given and one exception in end

2 C This event can trigger
changes in the tadpole’s physiology and dietary
preference, causing the tadpole to become larger and
exclusively carnivorous, feasting on other animals
including members of its own species.

3 B the inclusive fitness
theory posits that natural selection similarly favors
organisms that help their relatives, because doing so
also increases their own total genetic representation.

4 A Last line of 2nd para i guess last line of passage there are only 2 paras . that provides an exception

5 A Yet the
(40) cannibals have a procedure of discrimination whereby
they nip at other tadpoles, nip ( more than visual)

6 B Improvements in the general understanding of these
(5) mechanisms have turned some biologists’ attention to
the question of why kin recognition occurs at all.

7 E (20) The theory has helped to explain previously
mysterious phenomena, including the evolution of
social insect species like the honeybee,

8 A
 (60) simply as a means by which an organism preserves
its own life, not as a means to aid in relatives’ survival.
alternative cause : its not a cannibal, no issue of protection at all

carcass · Answer

5 out of 8 in 9 minutes not completely concentrated............mmmmm not so bad.

Please could you provide the last one OE (the contenders was B and C and I Picked B) ???

Thanks for the nice passage

PrashantPonde · Answer

OE for Question 8:
 
In the last sentence, the author concludes that kin
recognition in tiger salamanders can be explained as a
means for preserving their own life and not as a means
for aiding their relatives’ survival. While the evidence
regarding the deadly bacterium definitely supports kin
recognition being used to preserve the individual, there
is no evidence to say that kin recognition is not used
to aid relatives’ survival. The author ignores the
possibility that kin recognition may serve to protect
oneself and one’s relatives. To weaken the claim, the
correct answer choice will show a way that a tiger
salamander would use kin recognition to protect
someone other than itself.

(A) This has no relevance to the argument. What’s
impor tant is not whether the disease af fects
cannibalistic or noncannibalistic salamanders, but
whether or not it affects kin and kin recognition.
Eliminate.
(B) This discusses what makes salamanders
carnivorous or omnivorous, but it has no bearing on
why salamanders recognize kin. Eliminate.
(C) gives us a fact that would weaken the author’s claim.
If this were true, then kin recognition would provide a way
for salamanders to protect their offspring—thus making
kin recognition valuable beyond survival of the individual.
By protecting potential family, this weakens the author’s
claim that kin recognition is simply a self-serving device.
For the record:
(D) This answer misapplies some information from the
first paragraph about the number of offspring (part of
traditional evolutionary views). However, once again,
the number of offspring a salamander has is not
directly relevant to the reason for being able to
recognize kin.
(E) Even if this were true, according to the passage,
they’re still immune to the one deadly bacterium that’s
mentioned. And, because that particular bacterium is
more deadly when consumed through kin, the greater
immunity to other diseases isn’t necessarily relevant to
kin recognition.

It’s good to note for this question that the correct answer
is the only one that focuses on kin recognition, the Topic
of the argument the question asks us to weaken.

cumulonimbus · Answer

Hi,
why does breeding matter here. The paragraph talks about feeding only.

Also please provide OE for Q5.
5. The passage most strongly supports which one of the following statements about the mechanism by which cannibal spadefoot toad tadpoles recognize their kin?
(A) It is not dependent solely on the use of visual cues.
(B) It is neither utilized nor possessed by those tadpoles that do not become cannibalistic.
(C) It does not always allow a tadpole to distinguish its siblings from tadpoles that are not siblings.
(D) It is rendered unnecessary by physiological changes accompanying the dietary shift from omnivorousness to carnivorousness. 
(E) It could not have developed in a species in which all members are omnivorous.

PrashantPonde · Answer

Here is the OE for Q5:
The mechanism of a tadpole for recognizing kin is
described in lines 39–42. It involves nipping at other
tadpoles to determine whether they are siblings or not.
(A) is definitely supported by the information in the
passage. Nipping on other tadpoles is not a visual act,
so the mechanism seems to be at least partially based
on taste or touch. For the record:
(B) Outside the Scope. We know this is the behavior of
cannibalistic tadpoles, but we don’t know what
noncannibalistic tadpoles do. For all we know, they may
nip at other tadpoles, too. In fact, according to the
passage, tadpoles can become cannibalistic after first
accidentally eating another tadpole. So, it doesn’t
seem much of a stretch to consider that some
noncarnivorous tadpoles might also nip other tadpoles.
(C) Outside the Scope. Based on the last sentence, we
know that tadpoles will still eat siblings in extreme
circumstance. However, that’s not because the
mechanism doesn’t work—it’s because of hunger.
There’s no support for this.
(D) 180. The tadpoles utilize this mechanism after
changing physiologically and becoming carnivorous.
(E) 180. Line 32 states that all of these tadpoles start
life as omnivores. Furthermore, we don’t have any
information about other species beyond the tadpoles,
so we can’t infer this.

PrashantPonde · Answer

Taking note of where all examples appear, even
seemingly minor ones, can save research time when
questions ask about them.

The honeybees were mentioned at the end of the first
paragraph. According to the paragraph, the honeybees’
behavior of nur turing relatives was “previously
mysterious,” but the inclusive fitness theory helped
explain it. We want an answer choice that’s consistent
with this prediction.
(A) The behavior was known, it was just unexplained.
Eliminate.
(B) There’s no discussion of this kind of reciprocal
nurturing. Eliminate.
(C) While the new theory helps to explain this behavior,
the behavior was simply described as previously
mysterious. This suggests the behavior was merely an
enigma and not necessarily a catalyst for dismissing
traditional theory. Eliminate.
(D) is a grand distortion. The inclusive fitness theory
(which helps explain the honeybees’ behavior) still
states that evolution proceeds by natural selection—
just in a different way from what traditional theories
state. Eliminate.
(E) is a match. It was mysterious under traditional
theories, so some supplement (in this case, the
inclusive fitness theory) was needed to dispel some of
the mystery.

sreekanthssn · Answer

Hi Prapon ,
 
 For question 6 , the option E i.e The mechanisms operate differently in different species even when they serve exactly the same function also seems perfectly fine . Could you please explain the reasoning behind Option b ?Thanks in advance !

oasis90 · Answer

Can someone please explain Q4?

"A" makes sense. I just couldn't eliminate "C".

I thought 4C says that it lends support to what's mentioned 2nd paragraph which is this: 
The fact that this bacterium is more deadly when it comes from a close relative with a similar immune system suggests that natural selection may favor cannibals that avoid such pathogens by not eating kin.

Why is C wrong?

AdityaHongunti · Answer

Q2 :

i dont agree with OA :B
passage - that occasionally one tadpole eats another or eats a freshwater shrimp. This event CAN trigger changes in the tadpole’s physiology and dietary preference, causing the tadpole to become larger and exclusively carnivorous

2. The passage states which one of the following about some spadefoot toad tadpoles?
(A) They develop the ability to recognize fellow carnivores.- the cannibals have a procedure of discrimination whereby they nip at( they bite first and then recognize related tadbole) other tadpoles, eating non-siblings but releasing siblings unharmed. This shows the abiity to recognize fellow carnivores. - Ther are still too many errors in this AC: We dont know if this ability is inherent or developed later. How closely CANNIBAL characterisics resemble TADPLES not sure.
(B) They feed only upon omnivorous tadpoles.
(C) They change in body size when they become carnivores.- why wrong? 1. there is a probability mentioned and this AC makes a generalised statement. 2. There is no correlation or causation mentioned to say "they change in body size WHEN they become carnivores" 
(D) Their carnivorousness constitutes an important piece of evidence that calls into question the inclusive fitness theory.
(E) Their carnivorousness would not occur unless it contributed in some way to the evolutionary success of the spadefoot toad species.

Why cant we make an inference here? 
The passage states which one of the following about some spadefoot toad tadpoles? -- we are asked to find " what the passage STATES" so this has to be directly deductible from passage... rewording is allower but extra info nope.

If my reasoning is wrong please correct me

GittinGud · Answer

23 minutes, 5/8 correct. Can someone please help me with Q5? Option A says 'does not solely rely on visual clues'. This means that the tadpole has sight and uses visual clues. But nowhere in the passage is it mentioned that the tadpoles can see. They might be blind, sensing their surroundings through some other mechanism. Option A assumes that the tadpoles have sight.

Help is greatly appreciated. THanks!

Help is greatly appreciated. THanks!

GMATCoachBen · Answer

I found this passage on Khan Academy LSAT mini-test (which, by the way, is a great resource for extra RC and CR practice-- it includes 10 practice tests with solutions, as well as practice sets targeting specific CR question types).

workout, should we notify you or another modifier if we notice that a source could be tagged more specifically? Thanks

workout , should we notify you or another modifier if we notice that a source could be tagged more specifically? Thanks

GMATCoachBen · Answer

GittinGud  "does NOT SOLELY rely on visual clues" does NOT mean the tadpole has sight, it just means that <100% of its ability to recognize kin comes from visual cues -- it's possible that 0% could come from visual cues.

As a general rule, "not all" mathematically translates to <100%.

This question is a great example of a very common GMAT RC pattern I call "Infer Opposite" -- the wording of the answer is a negated version of what's said in the passage. As a very simple example, if the passage says "X is more than Y", the answer might say "Y is less than X".

The passage says "Yet the cannibals have a procedure of discrimination whereby they NIP at other tadpoles, eating non-siblings but releasing siblings". "Nip" is evidence of a mechanism other than "visual cues". So, A is a perfect match for this "Infer Opposite" pattern.

mSKR · Answer

Please post official answer for 4th.  PrashantPonde   Sajjad1994

Have some confusion among options A, E and C.

bM22 · Answer

Hi  imSKR ,

OE Is present as the spoiler just before the respective question.

Official Explanation

4. Which one of the following most accurately describes the function of the last sentence of the second paragraph?

Difficulty Level:   700

Explanation

When a sentence is presented in contrast to previous sentences, expect a wrong answer to be completely opposite of what you’re looking for. To understand the function of the last sentence of the second paragraph, you need to remember the function of everything that came before it. The bulk of the second paragraph was about the tadpoles that avoided eating siblings in order to improve the survival of their genetic lineage. This example was provided in support of the inclusive fitness theory. However, the last sentence begins with  “interestingly,”  suggesting that not all is as it seems. Sure enough, just as we’re being led to believe that tadpoles would spare family members to protect the genes, we learn that some tadpoles will eat their siblings after all—so as not to die from hunger. So, the Purpose seems to provide an instance that goes contrary to the other evidence, making the inclusive fitness theory seem inapplicable in certain cases.

Evaluate the Answer Choices:

Answer  Choice (A)  This seems like a good candidate. Just as we were being lulled into believing that the inclusive fitness theory was a winner, along comes this fact that throws a monkey wrench into the system. This is a match to our prediction.

Choice (B)  Outside the Scope. The fact in the last sentence is referring only to the spadefoot toad tadpoles, and makes no comparison to other species.

Choice (C)  This “interesting” note runs contrary to everything that came before it.

Choices (D)  Extreme. While it may question the validity of the inclusive fitness theory, it doesn’t necessarily make the tadpoles’ behavior unexplainable. In fact, it is explained—they’re very hungry and are more interested in saving themselves.

Choices (E)  The information that precedes the last sentence is not less relevant. It’s plenty relevant as support for why the inclusive fitness theory is plausible.

Answer: A

Hope This Helps.
Thanks.

HustleG · Answer

For anyone trying to figure out why option C is wrong in question 4, there are actually 3 paragraphs instead of 2 in the passage. The third paragraph starts with 'But there may be other reasons why organisms recognize kin.' Therefore, the last sentence of the second paragraph, by using the keyword interestingly, suggests that there may be other reasons for kin recognition, further complicating the issue.

I hope this helps clarify Q4!

I hope this helps clarify Q4!

mSKR · Answer

Yes , it makes sense of explanation of Q4. I agree with C option now. thanks!

bm2201  @Saajjad1994: can you please split the 2nd para into 2 parts as pointed out by  HustleG

Please also post the explanation of Q8.

I am confused with Option A .

Argument says: cannibalistic tiger salamanders don't eat their kins in order to save their lives not to spare kins' lives.

The conclusion can be weakened:
optionA: Even they don't eat any meat, still they can be infected with deadly bacterium. It means eating kin or not kin would not make difference. The whole arguments is shattered on the basis of which conclusion was made. Now this conclusion has no meaning. That was my reasoning for optionA.
I should reject A because this group is not our scope of focus?

Please suggest  GMATNinja   AndrewN   GMATCoachBen

Thanks!

AndrewN · Answer

Hello,  mSKR . Understanding the relationship between the last two sentences of the passage should help you appreciate why (A) does NOT undermine anything the author says in the last line.

Note the transition word in  then . This is a cue that tells that, based on the information that has come before, we can conclude what is about to follow. Essentially, it serves in the same capacity as  thus  or  therefore  at the head of a sentence. If you look at that previous line in the passage, you will see that it says exactly what (A) lays out: that cannibalistic (tiger salamander) larvae that avoid harmful bacteria by not eating their infected kin have a better chance of survival. We want an answer instead that would make us think that the tiger salamanders, larvae or not, were refraining from such behavior out of consideration for the other organisms. Choice (C) touches on this next-of-kin relationship by mentioning a behavior that the salamanders abstain from  in order to  protect  their offspring , organisms that are not themselves. Such information goes directly against the last line of the passage. Apparently, tiger salamanders would not be so self-centered after all.

I hope that helps.

- Andrew

nirajsawants · Answer

answer to question 8 is simply using elimination method

being cannibalistic or non cannibalistic doesn't matter because canibalastic will identify its kin be it omnivorous or cannibalistic so in turn support the last statement, so every option discussing about cannibalastic and non canibalistic is eliminated

djangobackend · Answer

Q6 - B is the answer - here is the passage reference "Mechanisms for recognizing kin are found throughout the plant and animal kingdoms, regardless of an organism’s social or mental complexity. Improvements in the general understanding of these mechanisms have turned some biologists’ attention to the question of why kin recognition occurs at all. " so indeed, e mechanisms have become more clearly understood, prompting interest in the purpose they serve. 
MISTAKE - I could not trace back this info. in the passage so marked E without understanding much.

E - The mechanisms operate differently in different species even when they serve exactly the same function.
here we know for a fact that kinship mechanism indeed operate differently in different species - honeybee, tadpoles, tiger salamanders BUT saying that "even when they serve exactly the same function." is incorrect since passage never mentions such a thing.

Q7 -
E because IFT is the thesis that explains this and we know that IFT itself is "partially explainable" so we indeed need more explanations to explain this completely.

I marked A - we don't know if its not "known to be true", we only know that IFT developed in 1960s but before 1960s did we know this information or not or was it solely IFT that helped us gain this knowledge we don't know.

Mechanisms for recognizing kin are found throughout the plant and anim

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Mechanisms for recognizing kin are found throughout the plant and anim

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