Evolution: a gradual process in which something changes into a different form; life forms changing over time.
Evolution is the gradual change in a species over geologic time, many thousands or millions of years. Natural selection refers to the fact that an organism which has the most effective way of dealing with the environment is most likely to survive. An example is sea otters; those with warmer thicker fur will survive cold northern waters better than another with less thick fur. The sea otters with thicker fur will survive to pass this trait on to their offspring, so that over time all sea otters end up with thicker fur.
An adaptation is a feature that an animal has that allows it to survive in its environment. Sometimes these adaptations are very similar among different animals. In fact, entirely different species can have the same type of adaptation to survive in similar environments. As mentioned above, wings (to fly and escape) and fins (to swim) are good examples. Other examples include:
To help in you discussion here are some criteria to determine valid examples of convergent evolution. In order to be considered an example of convergent evolution the animals must
In essence they must have similar structures with similar functions. For instance "tails" would not be a good example of convergent evolution because they are something shared by almost all vertebrates in their life cycle and also because they are not necessarily used for the same function. For example, horses use tails to swish flies and monkeys use tails for balance and certain monkeys use them to hang from trees.
Convergent Evolution is what occurs when two different species evolve similar structures from similar lifestyles.