The first thing that comes to mind is the Miller-Urey experiment. Look it up on google! Diagrams will help show exactly what the setup is but basically, adenine, one of the 4 bases that make up DNA, was created, in a closed system laboratory experiment, using only the basic known elements/compounds present at the beginning of the earths creation. This shows that over time, in the right conditions, new compounds can be made, and the way these compounds interacted with each other is what created DNA and was the first stepping stone to life. If even one factor had have been different, such as temperature or the introduction or removal of another element everything would have been different; life may not have been made or something new and totally unfathomable could have occurred.
a good example of evolution on a 'macro' scale is the phenotype (physical looks) of a moth. Moths are nocturnal creatures, so during the day they need a method of defense against their predators -there defense is their ability to blend in to particular surroundings. Grey moths blend in very well on birch trees making it difficult for brids to see them. A mutation in the gene coding for the color of the moth caused a moth to be black. This mutation, though not advantagous, can be passed down to the proceeding generation so long as the moth survives long enough to mate. So more and more moths may emerge into the population, however they are selected against because they stand out to predators during the day. In one particular area a factory was erected and because of the factory all the trees in the area were covered with soot turning the white birch black. Now, the once selected against black phenotype of the moth is no longer detremental but rather, has be come advantageous; the black moth now blends in on the tree during the day. So in this particular area the black moths flourish and thrive and are now the dominant color of their species in that area. Meanwhile in another area somewhere else in the world birch trees remain white and the original gene -the 'white gene'- is the gene selected for in that environment.
This is an example of how a simple mutation of a gene in DNA can have a huge impact on a given species. However, this mutation is not one which lead to speciation - the creation of a new species. It is important to remember that evolution is not something we can observe in a lifetime. Evolution is a series of mutations that occur over time which get passed down to succeeding generations; each of which prove to be advantageous to the environment in which the organism lives. Most mutations result in detrimental affects to the individual. It is an extraordinary event when a benifical mutation occurs.
Evolution occurs as a result of environmental stress and beneficial mutations. Due to the fact that humans reproduction rate is extremely slow (9 months for Homo sapien vs 20mins for escherichia coli) as well as the fact that, as humans, we alter our environment to suit our needs rather than adapt to our environment based on environmental stressors, some argue that further evolution for humans not likely. However, some individuals have extraordinary capabilities, such as the case with individuals having "synesthesia". Synesthesia is a condition in which one type of external stimulation evokes a sensation of another. For example, for some people having this condition or 'ability' different sounds allow them to see different colors, or, in more rare cases, specific tastes or smells cause the individual to see specific colors. How is this advantageous you ask? Well in an evolutionary sense it may not be. We do not need this ability to survive in our environment, and because of the society we've created it does not give us an advantage for life over another person who does not have this 'ability' but you've got to admit, it's a cool ability and hard to fathom. Studies on individuals with synesthesia have shown some benefits to having synesthesia. When read a list of items and told to recall them, initially the synesthesia-capable individual does no better than the average person in recalling the items, but, when asked hours later they can recall the majority of the list; more than they initially remembered. They have the ability to not only associate the items they are hearing into the schemas for which they have created for them, but they also have colors associated to each word.
It is a possibility that in the future we will be able to 'induce evolution' by manually applying specific genes to the genetic makeup of an individual. Not only will it be possible to select hair color, eye color, and even gender, but it is also possible to include genes such as the one(s) for synesthesia into the unborn individual - a true act of "playing god"; although it doesn't seem at this point anybody is really "playing" anymore.