A farmer has applied a pesticide to control a pest population that is affecting her crops. The pest population has reacted as shown below.

Which best describes the process that the pest population has experienced due to this environmental change?

A, genetic diversity

B. natural selection

C. natural resistance

D. genetic resistance

B.

Genetic diversity allows the different organisms to have different physiological characteristics. Some of them provides them with genetic resistence, others don’t. The ones which are resistent survive the pesticide, others don’t - that’s the natural selection. The ones which are resistent will live longer and have a larger offspring - that’s what we call reproductive success. From one generation to another, there will be more and more resistent pests (because of their larger offspring), and less and less unresistent pests (because they tend to die young). If the selection process goes on, someday the pesticide will be useless (it will kill no pest). That’s why it’s important not to abuse of pesticides or antibiotics.