Evidence of evolution includes fossils, homologous organs and analogous organs. Homologous and analogous organs show that how organs can modify themselves in the course of time to perform. These modifications over the time accumulate as variations that eventually lead to evolution. Fossils provide material evidence for evolution. The examination of dead remains of ancient organisms helps us to understand the course that evolution took. For example, Archeopteryx is a fossil which shows the connection between the birds and reptiles. It also provides the evidence that birds have evolved from reptiles.