Our understandings of evolution from Charles Darwin’s theory of evolution to recent discoveries in the fossil record and genetics have taught us much about the past and the progression of biodiversity. When thinking of evolution many assume that it is a process of nature that only occurs over long periods of time, taking millions of years to develop. For many species this assumption can be true, but evolution can also happen very rapidly and we even experience the impacts of evolution in our lives today.
As suggested in Darwin’s theory, evolution occurs by the process of natural selection, which is essentially “survival of the fittest.” When an environment changes it puts stress on an organism which are referred to as selection pressures. Those who have the right variation of traits to survive the selection pressures live and pass on those traits. This process is happening today and we are causing it through agriculture. The growth of our population has led to an increase in the amount of food we need support it. With this increase in demand for food production, we have taken many measures to ensure our livestock and crops do not fail. These measures put different strains on the ecosystem that results in selection pressures, causing evolution to take place right under our noses without us even realizing it.
With the overuse of antibiotics in livestock feed, we have put the selection pressures in place that created drug resistant bacteria strains. When antibiotics are used in livestock feed to prevent infection, they are creating the selection pressures to blame for drug resistance. While antibiotics kill off the susceptible bacteria, the selection pressures they cause create an environment that favors drug resistant bacteria. As this becomes more common we are forced to create new antibiotics and new methods for controlling these bacterial infections. This aspect of evolution occurred very rapidly, with the discovery of antibiotics only being within the last 100 years abc.net.
Just as antibiotic use creates drug resistant bacteria, we also are contributing to a rise in pesticide resistant agricultural pests. Using pesticides to control insect populations in crop fields is creating a selection pressure that is leading to more pesticide resistant insects. Pesticides affect more than just their targeted agricultural pests, over using pesticides affects the entire ecosystem around them. The use of DDT in the past shows the impact pesticides can have on the ecosystem when it decimated the populations of eagles. Using evolution to our advantage we could use alternative means to control agricultural pests by introducing predacious insect populations to our crop fields. By introducing predacious insects we would not have to be concerned about pesticide resistance, or affecting the surrounding ecosystem with chemicals.