QUESTION 1 Which of the following would NOT represent a direct observation of ev

Question

QUESTION 1 Which of the following would NOT represent a direct observation of evolution in response to selection? [1pt the origin of a morphologically distinct dog breed following 15 generations of artificial selection o mouse offspring become larger than their parents solely because of changes in the nutrition environment o the evolution of bacterial populations with higher fitness than their ancestors in Dr. Lenski's experiments O the rapid spread of bacterial resistance to penicillin in hospitals O a decline in the frequency of the allele causing sickle cell anemia (HbS) across generations in a human population where malarial parasites are absent

Explanation / Answer

Answer : B : Mouse offspring become larger that their parents solely because of changes in the nutrition environment.

Explanation : Because of difference in nutrition environment between the parent and the offspring, there is a change in size of the offspring. And, this is not related to evolutionary change in response to selection. Nutrition rich environment has helped the offspring to grow larger than parents and there is no change in genetic level or mutation.

Reason for incorrect options :

Evolution basically means development which is a slow stage process that depends on adaptation to different environments. If an organism is adapting to a new environment then it will be reflected in its genes and that is passed on to its generations.

Natural selection is based on the fact that individuals which can survive and reproduce at any given environment is the most fit. Hence, all the individuals in a population selected by natural selection will be most fit which can pass on its traits to next generation to increase the population size.

Adaptation to new environment or to any given environment, the changes need to be at the genetic level where mutation occurs. A change or mutation brings about a new trait which can adapt to new environment. Hence, natural selection preserves that trait or genetic variation by selecting that best fit individual from other non-adaptable traits. And, it can directly means that it preserves more genetic variation or traits which are called survival of the fittest.

A : Artificial selection helped in the direct observation of evolution and it resulted in morphologically distinct dog.

C : Dr.Lenski's experiment is the direct observation of evolution through selection because it has helped in producing bacterial populations with higher fitness.

D : Bacterial resistance to penicillin or other antibiotics is a best example for selection because bacterial populations adapted to new enviroment and survive to reproduce.

E : When malarial parasite is present, then the frequency of sickle cell anemia allele would increase in order to develp resistance to malaria

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