Question

Mosquitoes can carry and transmit many diseases to humans. In the past, the insecticide DDT was heavily used to reduce mosquito populations in order to reduce instances of disease transmission. However, after some time, mosquito populations developed a resistance to DDT, which made the DDT less effective in reducing mosquito populations. Based on what you’ve learned about natural selection, in 3–5 sentences, describe how mosquitoes may have come to develop this resistance.

Answer 1

Mosquitoes may have developed resistance to DDT through natural selection. Some individual mosquitoes in the population may have had genetic variations that made them more resistant to the effects of DDT. When DDT was used, the mosquitoes that were not resistant died off, while the resistant mosquitoes survived and passed on their resistance genes to their offspring. Over time, the population of mosquitoes became predominantly composed of individuals with the resistance gene, making DDT less effective in reducing their numbers. This is a classic example of evolution through natural selection, where the environment (in this case, the presence of DDT) exerted selective pressure on the mosquito population, leading to the development of resistance.