Why is bacteria and insects becoming resistant to pesticides?

Stupid Biology Work!

Why is bacteria and insects becoming resistant to pesticides?
Because of evolution!





Pesticides are poisons that kill the bacteria and insects they are used on. Those dead bacteria and insects do not manage to reproduce. When a bacterium or insect manages to survive the pesticide, it will go on to reproduce and pass its genes on to its offspring. That means the resistant individuals will produce a new generation of resistant individuals but the dead individuals do not produce anything.
Reply:evolution!
Reply:They are building up immunity?
Reply:The ones that are not suited to living under those conditions die off and leave only the ones with genes that are immune or resistant to it leaving those to reproduce and having a greater chance of passing those genes on.
Reply:Natural selection.





Darwin's theory of evolution stated this process was driven by certain members of a variable population being better adapted to a particular set of environmental conditions. Over time, these traits would help these members of the population reproduce more offspring, which would then inherit these traits. Eventually all the population would come to be dominated by those individiuals expressing the favorable trait.





In the case of resistance, the application of pesticides and antiobiotics kills off most, but not all the members of a population. Those having resistance go on to breed resistant offspring. Eventually all the population will become resistant. This process is enhanced by heavy doses of pesticides and antiobiotics. This practice ensures those individuals able to be killed are eliminated entirely from the population.





DDT is a good example of a pesticide which rapidly became useless because of insect resistance. Insect resistance is also helped by the fact the pesticide also kills insect preditors, whose population is naturally lower then their prey. The pest species is able to recover faster than the preditor. The usual stragety to counter resistance is to switch to another compound, but if it is over used, strains of multi-resistant organisms evolve. This is the case of certain strains of stalph bacteria.





Tuberculosis becomes resistant for the opposite rerason. Patients stop taking medication when they begin to feel better. The bacteria then are able to recover and generate enough resistance to be able to withstand increased dosages when the symptoms return. Another antiobiotic is then used, but the scenario is often repeated. This is why people with multi-resistant tuburculosis are frequently quarrentined and forced to take all their medication.
Reply:Evolution - sensible answer and yes it is because of this evolution that those pests adapt and evolve to become resistant to the toxic effects of pesticides.


All organism try to survive even in the harshest of conditions.


In times of such hardship, a small fraction of the populace mutate to evolve into a more efficient specie of that genre.


Although mutations are happening always spontaneously, most are harmful and cause serious complications, however, for a tiny number, these genetic modifications bring hope for better life!





Immunity - WRONG


Pesticides are chemical substances that doesn't trigger any immuno-activities.