Bunuel wrote:
Biologist: Some speculate that the unusually high frequency of small goats found in island populations is a response to evolutionary pressure to increase the number of goats so as to ensure a diverse gene pool. However, only the reproductive success of a trait influences its frequency in a population. So, the only kind of evolutionary pressure that can reduce the average size of the members of a goat population is that resulting from small goats achieving greater reproductive success than their larger cousins.
The biologist’s view, if true, provides the most support for which one of the following?
(A) The evolutionary pressure to ensure a diverse gene pool could have the effect of increasing the frequency of a gene for small size.
(B) The unusual frequency of small goats in island populations is not a result of the greater reproductive success small goats possess when space is limited.
(C) Contrary to what some believe, large goats achieve greater reproductive success than small goats even when space is limited.
(D) The evolutionary pressure to ensure diverse gene pool does not have the effect of increasing the frequency of a gene for small size.
(E) A diverse gene pool cannot be achieved in a goat population unless the average size of its members is reduced.
Lets first understand what the biologist is saying, in simple terms.
Biologist : Some people think that the small goats are being born more frequently, because evolution wants to increase the number of small goats to ensure a diverse gene pool.However, only the reproductive success of small goats or large goats influences its frequency in a population. So the reason for the larger number of small goats is, smaller goats are having greater reproductive success and NOT because evolution wants a diverse gene pool.
So biologist view provides most support for which of the following?Options:
(A) The evolutionary pressure to ensure a diverse gene pool could have the effect of increasing the frequency of a gene for small size :
Biologist believes only reproductive success ensures a demographics frequency and hence its numbers NOT evolution's pressure to ensure a diverse gene pool.INCORRECT (B) The unusual frequency of small goats in island populations is not a result of the greater reproductive success small goats possess when space is limited :
Actually biologist believes just the OPPOSITE. He believes only the reproductive success of small goats ensures its higher frequency.INCORRECT(C)Contrary to what some believe, large goats achieve greater reproductive success than small goats even when space is limited:
Larger goats in the passage have just the opposite scenario.Clearly Biologist does not believe so.INCORRECT(D)The evolutionary pressure to ensure diverse gene pool does not have the effect of increasing the frequency of a gene for small size :
CORRECT. It is the reproductive success rate of small goats that is causing their higher frequency and NOT evolution's pressure for having a diverse gene.(E)A diverse gene pool cannot be achieved in a goat population unless the average size of its members is reduced.:
Biologist is clarifying what is the reason for a larger frequency of small goats. No where is he saying this.INCORRECTHope it's clear .
Ans- D