Excessive and continous use of pesticides has resulted in evolution of some new species of pests. Explain what must have led to this. What is this type of evolution called ?

Explanation

Farmers spray higher doses of pesticides and excess use of herbicides which resulted in selection of resistant varieties in a much lesser time scale.
Evolution is not a directed process ir the sense of determinism. It is a stochastic process based on chance events in nature and chance mutation in the organisms. This type of evolution is called 'ntural selection'.