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.

Answer 1

This resistance to DDT is an example of natural selection at work. Mosquitoes that were genetically resistant to DDT had a survival advantage and were more likely to survive and reproduce, passing on their genetic resistance to their offspring. Over time, the proportion of resistant mosquitoes in the population increased, reducing the effectiveness of DDT as a control method.

As a result, new methods of mosquito control have had to be developed. This includes the use of alternative insecticides, such as pyrethroids, and the use of biological control methods, such as introducing mosquito predators or infecting mosquitoes with a bacterium that reduces their ability to transmit disease. Understanding the mechanisms of resistance and developing new control methods is crucial in preventing the spread of mosquito-borne illnesses.