Which of the following is an example of microevolution?

Microevolution 

An allele is one of the two or more versions of a mutation at a certain location on a chromosome that is typically known, it is a variant form of a specific gene. To simply put into other words, it is a physical trait that gets expressed in a population causing fine and indistinct changes. However, the immediate changes do not reflect predominantly on the progeny. It can also be defined in the context of the Hardy-Weinberg equilibrium – “the allele frequencies change if any of the criteria of Hardy-Weinberg equilibrium is not fulfilled”.

It is also important to note that microevolution can perhaps lead to speciation, serving as a raw material for the process of macroevolution which is caused due to accumulation of changes from the process of microevolution. Hence, it can be deduced that both microevolution and macroevolution follow similar procedures, the difference being the time scale. In terms of evolution, this change occurs in a shorter frame in comparison to macroevolution. 

The change that microevolution entails can be attributed to the following processes – Natural and artificial selection, Mutation, Genetic drift and Gene flow . 

Some examples of microevolution through the process of natural selection are herbicide resistance, pesticide resistance, antibiotic resistance and so on. Few other generally noticeable evolutionary instances of microevolution are the bacterial strains incorporating the property of resistance to antibiotics.

Few other examples are as listed below:

• Resistance to pesticides by whiteflies
• Resistance to DDT by mosquitoes
• HIV strains developing resistance to antiviral medicines
• Gonorrheal bacteria strains developing resistance to penicillin .