When a given phenotype evolves, the underlying genetic mechanism may be different in distantly related species (convergent), but similar in closely related species (parallel).
Groups of species undergo various kinds of natural selection and engage in several patterns of evolution.
Sometimes evolutionary change follows a common pathway in two or more unrelated or distantly - related organisms because of similar environmental pressures. It results in unrelated organisms with similar morphological characteristics even though they did not have a common ancestor. This phenomenon is called as parallel evolution.
A classic example of parallel evolution is found among plants, in which several similar but distinct forms of leaf evolved in parallel and are evident today.
When parallel evolution under similar environmental conditions in distantly related organisms results in plants and animals that are morphologically very similar in overall appearance, it is called convergent evolution.
Dragon flies, hawks, and bats all have wings. None of these organisms owes its wings to genes inherited from any others. Each kind of wings evolved independently and are called analogous structures.