Populations of a shrimp species at eleven different Indonesian coral

Populations of a shrimp species at eleven different Indonesian coral reefs show substantial genetic differences from one reef to another. This is surprising because the area’s strong ocean currents probably carry baby shrimp between the different reefs, which would allow the populations to interbreed and become genetically indistinguishable.

Which one of the following, if true, most helps to explain the substantial genetic differences among the shrimp populations?
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(A) The genetic differences between the shrimp populations are much less significant than those between shrimp and any other marine species.
(B) The individual shrimp within a given population at any given Indonesian coral reef differ from one another genetically, even though there is widespread interbreeding within any such population.
(C) Before breeding, shrimp of the species examined migrate back to the coral reef at which they were hatched.
(D) Most shrimp hatched at a given Indonesian coral reef are no longer present at that coral reef upon becoming old enough to breed.
(E) Ocean currents probably carry many of the baby shrimp hatched at a given Indonesian coral reef out into the open ocean rather than to another coral reef.





Source: LSAT

Kudos

But if interbreeding itself does not lead to genetic similarities , then even if they did not return back to their original reef , and did indeed interbreed then also there would be genetic differences . This could also explain the discrepancy.

This is what option B says, it says even within a particular reef there is wide genetic differences even though there is interbreeding , so these same shrimps when transferred to other reefs and after interbreeding could lead to the same result, i.e. genetic differences would be prevalent.

So why is B wrong?

Hi,

I think you're questioning the premise - "which would allow the populations to interbreed and become genetically indistinguishable", which should be taken as a fact.

Actually, information provided by option (B) is not related to the paradox needed to be solved. We need to find out why interbreeding between DIFFERENT populations from DIFFERENT coral reefs results in genetics differences, while option (B) focuses on interbreeding between individuals of the SAME population in the SAME reef. U see? This information doesn't help. (B) is gone.

Nowhere does it state that interbreeding actually occurs. It simply states that interbreeding would be potentially occur given that genetically different shrimp do come into contact with each other. One way to resolve this paradox would be to prove that interbreeding does not occur even if it is "possible". Answer choice C does just that - It explains why shrimp may not interbreed even though they do come in contact with one another.

Populations of a shrimp species at eleven different Indonesian coral reefs show substantial genetic differences from one reef to another. This is surprising because the area’s strong ocean currents probably carry baby shrimp between the different reefs, which would allow the populations to interbreed and become genetically indistinguishable.

Which one of the following, if true, most helps to explain the substantial genetic differences among the shrimp populations?

(A) The genetic differences between the shrimp populations are much less significant than those between shrimp and any other marine species.
(B) The individual shrimp within a given population at any given Indonesian coral reef differ from one another genetically, even though there is widespread interbreeding within any such population.
(C) Before breeding, shrimp of the species examined migrate back to the coral reef at which they were hatched.
(D) Most shrimp hatched at a given Indonesian coral reef are no longer present at that coral reef upon becoming old enough to breed.
(E) Ocean currents probably carry many of the baby shrimp hatched at a given Indonesian coral reef out into the open ocean rather than to another coral reef.

Source: LSAT

Kudos

Resolve the Paradox. The correct answer choice is (C)

Your task in this Paradox question is to select the answer choice that provides an active resolution to
the apparent discrepancy presented in the stimulus.

This stimulus is quite generous, expressly stating the apparent paradox. Even though the area’s
strong ocean currents probably carry baby shrimp between the different reefs, which would allow for
the shrimp populations to interbreed and become genetically indistinguishable, the populations of a
shrimp species at eleven different coral reefs show substantial genetic differences from one reef to
another.

The correct answer choice will provide information that causes this surprising situation to occur, i.e.,
that causes the shrimp species to have substantial genetic differences despite the area’s strong ocean
currents. The incorrect answers will not provide an active resolution the apparent paradox, either
because they merely support one side, attack one side, or are irrelevant to the conclusion.

Answer choice (A): This information merely supports the fact that the shrimp populations are
genetically different, though their respective differences are less than between the shrimp and other
marine species.

Answer choice (B): This choice is irrelevant to the paradox, because it refers to individual shrimp
within a given population, while the paradox was concerned with genetic differences between shrimp
belonging to distinct coral reefs.

Answer choice (C): This is the correct answer choice. This choice helps to resolve the paradox
by showing that although the strong ocean currents may carry the baby shrimp between reef
populations, the shrimp return to the coral reef at which they were hatched before breeding. This
migration would reduce the possibility that the species would interbreed.

Answer choice (D): This choice merely supports the fact that the shrimp migrate from the reefs at
which they are hatched.

Answer choice (E): This choice attacks the idea the that currents carry the shrimp between the reefs,
stating instead that the shrimp are carried out into the open ocean.

Answer:C

Populations of a shrimp species at eleven different Indonesian coral reefs show substantial genetic differences from one reef to another. This is surprising because the area’s strong ocean currents probably carry baby shrimp between the different reefs, which would allow the populations to interbreed and become genetically indistinguishable.

Which one of the following, if true, most helps to explain the substantial genetic differences among the shrimp populations?

(A) The genetic differences between the shrimp populations are much less significant than those between shrimp and any other marine species. -We are not worried about the other marine species.
(B) The individual shrimp within a given population at any given Indonesian coral reef differ from one another genetically, even though there is widespread interbreeding within any such population. -We need not be worried about the distinction among the shrimp at a given location. We are worried about the shrimps' DNA at 11 different locations.
(C) Before breeding, shrimp of the species examined migrate back to the coral reef at which they were hatched. -CORRECT. It tells us that even though the shrimps are carried to other coral reefs by ocean currents, they are go back to their native place before breeding, which is responsible for the reduction in diversity.
(D) Most shrimp hatched at a given Indonesian coral reef are no longer present at that coral reef upon becoming old enough to breed. -Irrelevant
(E) Ocean currents probably carry many of the baby shrimp hatched at a given Indonesian coral reef out into the open ocean rather than to another coral reef. -It is a possibility that is not refuted by the author. But it definitely doesn't help us explain the genetic diversity, because some shrimps are definitely carried over to other coral reefs.

Hope it helps !!
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Give kudos if this helped !

Populations of a shrimp species at eleven different Indonesian coral reefs show substantial genetic differences from one reef to another. This is surprising because the area’s strong ocean currents probably carry baby shrimp between the different reefs, which would allow the populations to interbreed and become genetically indistinguishable.

Which one of the following, if true, most helps to explain the substantial genetic differences among the shrimp populations?


(A) The genetic differences between the shrimp populations are much less significant than those between shrimp and any other marine species.

(B) The individual shrimp within a given population at any given Indonesian coral reef differ from one another genetically, even though there is widespread interbreeding within any such population.

(C) Before breeding, shrimp of the species examined migrate back to the coral reef at which they were hatched.

(D) Most shrimp hatched at a given Indonesian coral reef are no longer present at that coral reef upon becoming old enough to breed.

(E) Ocean currents probably carry many of the baby shrimp hatched at a given Indonesian coral reef out into the open ocean rather than to another coral reef.

Source: LSAT