The current bed bug epidemic is a great example of darwinian evolution at work. Unfortunately they are evolving beyond the reach of common household pesticides, making this even more of a problem, particularly in the Northeastern United States.
For those who aren't aware, these days according to the National Pest Management Association, the common bed bug is the most difficult insect to treat. They are master hitchhikers, using humans to move from location to location. Once they hop off the host, they are great at hiding in small crevices, making them difficult to spot.
Unfortunately, when a bed bug infestation is identified, current treatment options are proving to be ineffective. The reason is that the bed bug population has developed an insecticide resistant strain. Worse still, this strain exists in areas such as the Northeastern United States.
For example, DDT, once the most toxic substance for killing bed bugs, now demonstrates no killing action against insecticide resistant strains. Given the simple bed bugs ability to evolve over time, it's no wonder that they continue to plague mankind.
So the next time you are looking for signs of Darwinian evolution, you need to look no further than the lowly bed bugs.