Question

Which one of the following phenomena supports Darwin's concept of natural selection in organic evolution?

• 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

Answer 1

Answer: (C)

Prevalence of pesticide resistant insects supports natural selection theory, e.g., $DDT$ was thought to be an effective insecticide against household pests (like mosquitoes, houseflies, body lice, etc.) in $1945$. But, within $2$ to $3$ years of its introduction, new $DDT$ resistant mosquitoes appeared in the population. These mutant strains, soon became well established in the population by natural selection and thus replaced the original $DDT$ - sensitive mosquitoes