Quick Evolution?

True or false:

Evolution occurs so slowly that scientists are unable to witness it happening

Before we talk about the answer, lets get a little context for why I would ask this. One of the common misunderstanding about evolution is that it can't be proven because it occurs over very long periods of time and therefor can't be directly witnessed. While it's true that the ENTIRETY of evolution which has led to the present diversity of life on Earth took billions of years to happen, and species in nature often change very slowly, there are also well documented cases of organisms evolving, in the wild, in a relatively short period of time.

My current favorite example of relatively quick evolution can be seen in a certain strain of bacteria that has actually developed the ability to produce enzymes called "nylonases", which are able to break down and essentially feed on the waste products from the production of nylon. Nylon is a man-made fiber that was first produced in 1935, and the bacteria was discovered in a waste pond that where a nylon-producing factory was dumping its waste water.

By studying these bacteria, biologists were able to conclude that the nylonases were completely different than any other enzyme produced by these types of bacteria. Further testing also showed that these enzymes were specific to nylon, meaning they didn't work on any other material or chemical, and therefor probably arose after nylon began being mass produced.

By studying the genome of these bacteria, scientists eventually were able to pinpoint the exact spot on the organisms' DNA where the mutation occurred that caused the bacteria to stop producing a normal enzyme and begin producing the nylonase. In most instances, a mutation affecting a major digestive enzyme would be extremely harmful for an organism. In this case, however, it allowed these bacteria to flourish in a nylon-rich environment.

This is a perfect example of evolution in nature. Random DNA mutations cause some organisms to develop traits that make them better adapted to their environment. These organisms are more likely to reproduce and pass on the genes containing those beneficial mutations. Over time (in some cases long period of time, but in this case only a few decades) the population of organisms becomes significantly different than its biological ancestors.