An example of evolution would be when pesticide is over used by a farmer. Sooner or later the pesticide will not affect the insect, because the insect will become so use to the the pesticide that the next time the farmer sprays the pesticide the insect will go on like nothing happened.
In embryology evolution has happened various times because like a monkey is born with a genetic mutation. That mutation is that the monkey does not have a tail. Later on that monkey will have others monkeys and pass on the trait and sometime over evolution that species might start a new species.
In Herbicides a person will start spraying the herbicide killer Round-Up. That person uses Round-Up to clean the weeds out of his driveway and soon some of those weeds will not be affected by the weeds so the person will eventually have to find a new type of spray like Grazeon.