Resistance is an inevitable result of evolution

Lethal toxicants in the environment will, of course, have a dramatic effect on the population. Only those individuals that for some reason survive are able to reproduce. An individual with alleles or gene duplications that make it less sensitive to the toxic environment will have much better opportunities to reproduce. The next generation of the pest will therefore have a higher frequency of these alleles. If the pest organism cannot be completely wiped out by the pesticide or by other means, resistance will appear sooner or later. Pesticides can therefore be regarded as consumable with a restricted time of usefulness. After having been used some years, the development of resistance may render them useless. 

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Because resistance is an inevitable result of evolution, it should have been predicted before becoming a problem. How fast resistance develops and in what species, as well as the biochemical mechanisms behind it and how... 

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