Evolution Question 46
46. Which one of the following phenomena supports Darwin’s concept of natural selection in organic evolution?
[2005]
(a) Development of transgenic animals
(b) Production of ‘Dolly’, the sheep by cloning
(c) Prevalence of pesticide resistant insects
(d) Development of organs from ‘stem cells’ for organ transplantation
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Answer : c
Hints & Solution
(c) When DDT was sprayed to kill mosquitoes, there were only few mosquitoes which were already resistant to DDT, and hence survived. Most of the mosquitoes which were sensitive to DDT died. Due to differential reproduction the resistant mosquitoes got more chances of reproduction and multiplied. After few generations most of the mosquitoes were resistant. The sensitive were very few. This supports Darwin’s theory of natural selection and survival of the fittest.