Question

MAKE CONNECTIONS The bacterium Wolbachia is a symbiont that lives in mosquito cells and spreads rapidly through mosquito populations. Wolbachia can make mosquitoes resistant to infection by Plasmodium; researchers are seeking a strain that confers resistance and does not harm mosquitoes. Compare evolutionary changes that could occur if malaria control is attempted using such a Wolbachia strain versus using insecticides to kill mosquitoes. (Review Figure 28.16 and Concept 23.4.)

Short answer

The pattern of inheritance and the evolutionary changes would be different when the strain of Wolbachia is used. The evolutionary change would be different when the insecticides are used to kill the mosquitoes carrying the infection. In both cases, natural selection plays its role.

When Wolbachia strain is used, mosquitoes become resistant to Plasmodium, and when insecticides are used, the mosquitoes that are resistant to the insecticides are selected.

Step-by-step solution

Malaria

Malaria is an infectious disease that is also referred to as a zoonotic disease. The infection spreads from the infected mosquitoes to healthy humans. The infection occurs when the female anopheles mosquito injects the sporozoites of Plasmodium.

Evolutionary approach when Wolbachia strain is used.

A strain of Wolbachia is used to prevent the spread of malaria without harming the mosquitoes.The mosquitoes then confer resistance to the Plasmodium and then rapidly pass it on to other mosquitoes. However, the Plasmodium that is resistant to Wolbachia is selected through natural selection.

Therefore, the Plasmodium undergoes evolution.

Evolutionary approach when insecticides are used

When insecticides are used to kill mosquitoes, the mosquitoes confer resistance to insecticides are selected via natural selection. The other mosquitoes are thus killed. Therefore, in this scenario, the mosquito undergoes evolution.