Since the time of Darwin, morphological structures have been used to

Question

Aristotle RC 99 - Passage 58     
   Since the time of Darwin, morphological structures have been used to identify  phylogenetic  relations. For example, the similarity between a man‘s arm and a bat‘s wing is taken as evidence of their common origin. There are innumerable examples of this in nature. From the whiskers of lions and domestic cats to the bone structure in the fins of a whale and that of a human hand, it seems one would be hard pressed to fine an attribute in a particular species that did not illustrate some kind of relationship to another species.

Similarities in behaviour patterns can also serve in reconstructing evolutionary history. It is not always clear, however, how certain types of innate behaviour evolved through natural selection. In its modern form the Darwinian interpretation of evolution asserts that evolution consists of changes in the frequency of appearance of different genes in populations, and that the frequency of the appearance of a particular gene can only increase if the gene increases the "Darwinian fitness" (the expected number of surviving offspring) of its possessors.

The discovery of a genetic predisposition to be especially responsive to certain stimuli was an important contribution to the study of evolution. Genetically determined responses must be subject to the pressures of natural selection. Hence innate behaviour must evolve. Ethologists were able to show how a motor pattern employed in a noncommunicatory context such as feeding could evolve into a ritualized form employed as a signal in, say, courtship.

Differentiation in innate behaviour patterns could be traced to selection pressures arising from the environment. There are many instances of animal behaviour patterns that seem not to contribute to the survival of the individual displaying that behaviour. The classic example is the behaviour of the worker bee: this insect will sting an intruder and thereby kill itself in defense of the hive. The problem is evident: How can a gene that makes suicide more likely become established? The concern over this type and other types of apparently anomalous behaviour led to the development of a new phase in the study of the evolution of behaviour: a marriage of ethology and population genetics.

Animal behaviour was formerly thought to consist of simple responses, some of them innate and some of them learned, to incoming stimuli. Complex behaviour, if it was considered at all, was assumed to be the result of complex stimuli. Over the past 60 years, however, a group of ethologists, notably Konrad Lorenz, Nikolaas Tinbergen and Karl von Frisch, have established a new view of animal behaviour. Studying whole patterns of innate animal behaviour in natural environments (rather tha focusing primarily on learned behaviour, as animal behaviourists do), they have shown that the animal brain possesses certain specific competences, that animals have an innate capacity for performing complex acts in response to simple stimuli. As Gould put it in 1982, "Rather than encompassing merely the rigid and impoverished behavioural repertoire of primitive organisms, instinct has been shown to possess a stunning flexibility and overwhelming richness. As a result, we no longer need to invoke the barren behaviouristic tenet of learning as an 'explanation‘ of complexity."
Source:RC99   1 
1. In the context of the arguments being made by the author in this passage, the term "phylogenetic" (line 2) most closely means:
A. structural.
B. inter-species.
C. innate.
D. functional.
E. acquired 2 
2. Which of the following scenarios would be most analogous to the example given by the author of the worker bee?

A. A male spider reacts to intruding predators by releasing venom that kills both the predator and itself.

B. A female marsupial abandons her weakest offspring as prey for her natural enemies in order to protect the rest of her brood.

C. The youngest member of a canine pack sacrifices himself by fatally wounding an attacking predator so that the pack itself can escape.

D. A drone ant kills an insect preying on his collective by stinging the insect‘s eyes.

E. A young Cheetah tries to hunt and fails repeatedly 3 
3. The author of the passage would be most likely to agree with which of the following statements?

A. Unusual animal behaviours can be understood in terms of natural selection when they are studied in the context of procreation patterns and needs for survival of that particular species.

B. Overpopulated animal colonies often weed out their excess or weak members by abandoning them to their natural predators.

C. Darwin‘s evolutionary theories of natural selection have been unnecessarily modified by modern scientists in order to make them accord with bservations of animal behaviour patterns.

D. The evolution of certain types of innate animal behaviour demonstrate the inadequacy of the notion of "Darwinian fitness" as an approach to studying evolution.

E. There are some natural phenomena that cannot be explained by logic

rahulkashyap · Answer

can we have an explanation for question 3 please

dvishal387 · Answer

1. In the context of the arguments being made by the author in this passage, the term "phylogenetic" (line 2) most closely means:

Since the author is trying to bring out the similarities between species it should be B.
A. structural.-Author uses structuctural similarities to show the similarites among species.
B. inter-species.-Correct choice
C. innate- The author does not mean this
D. functional.- The author does not mean this
E. acquired-The author does not mean this

2. Which of the following scenarios would be most analogous to the example given by the author of the worker bee?

We need an option where the one attacking gets killed Only in option C we see that. In other choice the attacker/the spider in case
1 or cheetah are not killed.So C is the correct choice.

A. A male spider reacts to intruding predators by releasing venom that kills both the predator and itself.

B. A female marsupial abandons her weakest offspring as prey for her natural enemies in order to protect the rest of her brood.

C. The youngest member of a canine pack sacrifices himself by fatally wounding an attacking predator so that the pack itself can escape.

D. A drone ant kills an insect preying on his collective by stinging the insect‘s eyes.

E. A young Cheetah tries to hunt and fails repeatedly

3. The author of the passage would be most likely to agree with which of the following statements?

A. Unusual animal behaviours can be understood in terms of natural selection when they are studied in the 
context of procreation patterns and needs for survival of that particular species.- In the lines -"...a new phase in 
the study of the evolution of behaviour: a marriage of ethology and population genetics." The author explains how a certain action can lead 
to killing of individual but benefit to the species. In the example given in passage the bee dies but the sacrifice helps the species survive for
further procreation.

B. Overpopulated animal colonies often weed out their excess or weak members by abandoning them to their natural predators- The author nowhere 
seems to be pointing to such a thought.

C. Darwin‘s evolutionary theories of natural selection have been unnecessarily modified by modern scientists in order to make them
 accord with bservations of animal behaviour patterns-The author does not suggest any such thing instead talks 
about "Studying whole patterns of innate animal behaviour in natural environments ..." to study such behaviour.

D. The evolution of certain types of innate animal behaviour demonstrate the inadequacy of the notion of "Darwinian fitness" 
as an approach to studying evolution- The author dicusses the notion of "Darwinian fitness" in another context when he talks abouthow frequency of appearance of 
different genes is decided in populations. A is a better choice than this.

E. There are some natural phenomena that cannot be explained by logic - Cannot be inferred.

sananoor · Answer

I have no idea how come i answered all questions right

rahulkashyap the last para helps u answer question 3 and i used POE too 3. The author of the passage would be most likely to agree with which of the following statements? A. Unusual animal behaviours can be understood in terms of natural selection when they are studied in the context of procreation patterns and needs for survival of that particular species. (the last line of 2nd passage as well as last passage actually deals with this) B. Overpopulated animal colonies often weed out their excess or weak members by abandoning them to their natural predators. (this isnt mentioned anywhere) C. Darwin‘s evolutionary theories of natural selection have been unnecessarily modified by modern scientists in order to make them accord with observations of animal behavior patterns. (author no where agrees that Darwin's evolutionary theory is unnecessarily modified) so i ruled this out D. The evolution of certain types of innate animal behavior demonstrate the inadequacy of the notion of "Darwinian fitness" as an approach to studying evolution. (again its not mentioned anywhere) E. There are some natural phenomena that cannot be explained by logic (this option is really attractive but problem is that no where in passage it is explicitly said, yes author agree with the last line "As a result, we no longer need to invoke the barren behaviouristic tenet of learning as an 'explanation‘ of complexity." but nothing about logic

faltan · Answer

can anyone explain 2nd? For me A makes more sense than C

dvishal387 · Answer

The question asks for a scenario analogous to the worker bee example given in passage.
For the worker bee the author says - "..the worker bee: this insect will sting an intruder and thereby kill itself in defense of the hive"
which means the action leads to killing of individual but benefit to the species.
Now in choice A - A male spider reacts to intruding predators by releasing venom that kills both the predator and itself does not mean that
the spider is doing so for benefit to the species and in case of worker bee we are not sure whether the intruder gets killed or not.So, choice C
The youngest member of a canine pack sacrifices himself by fatally wounding an attacking predator so that the pack itself can escape is 
the best option where The youngest member of a canine pack sacrifices himself for the benefit of its pack(species).

Hope its clear.

sanathadiga · Answer

I took 9 minutes to do all the 3 questions. Is this ok ? I can't answer the questions unless i read the passage. I usually end up answering each of other questions within 1 min, but i took around 1.5 minutes to answer each question( 3 8 1.5) plus 4 minutes to read the passage

AdityaHongunti · Answer

Please do not stress on this passage . The time you spent is in fact appropriate. Additionaly, this passage is NOT AT all representative of real GMAT passages. The LENGTH,the complexity is not at all representative of real GMAT.

P.S. - Aristotle is like the last source you should opt for. Just try to build strategies from these passages. Do not at all worry about timing. If you did this in 9 mins then youd probably do a GMAT hard passage within 7 mins.

richirish · Answer

5 mins all correct, difficult passage indeed, happy to help if required!

Avani12 · Answer

Could you please tell me what prompted you to choose A over D in question 3? Thank you.

bM22 · Answer

Hi  Avani12 ,

Let me know if this helps.

Correct , as can be inferred from the second and third paragraph: " Genetically determined responses must be subject to the pressures of natural selection.  Hence innate behaviour must evolve. Ethologists were able to show how a motor pattern employed in a noncommunicatory context such as feeding could evolve into a ritualized form employed as a signal in, say, courtship. Differentiation in innate behaviour patterns could be traced to selection pressures arising from the environment.  There are many instances of animal behaviour patterns that seem not to contribute to the survival of the individual displaying that behaviour."

D is incorrect  as author mentions that Darwin's ideas are important as can also be inferred from the lines: "The discovery of a genetic predisposition to be especially responsive to certain stimuli was an  important contribution to the study of evolution ".

Hope This Helps.
Thanks.

VerbalBot · Answer

Hello from the GMAT Club VerbalBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.

Since the time of Darwin, morphological structures have been used to

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Reading Comprehension (RC) Questions

Since the time of Darwin, morphological structures have been used to

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards