* Fossils- fossils provide evidence of evolution because related organisms have similar but varied bone structures. Carbon dating and radioisotopes allow scientists to find when the rocks and fossils lived, allowing them to see how the organisms changed over time and adapted to new environments.
* Embryology- many animals have an extremely similar embryological stage. Only trained professionals can tell the difference between the embryos of humans, fish, rabbits and birds. Only once the embryos grow and develop do they start varying in their appearance. This provides evidence of evolution because it shows how almost identical embryos turn into completely different organisms. The more similar the embryo, the more closely related the organism is.
* Comparative anatomy- states that organisms with similar structures must have come from a common ancestor. When two different species that have homologous structures, proves that they both evolved from the same species and adapted in order to survive.
* Geographical distribution- the theory different animals have different traits because of the environment where they live and are raised. This proves evolution because divergent evolution explains that when something happens to environment that threatens the species’ existence, they must all flee the area. The different areas have different effects on the species, causing it to adapt to the environment. After millions of years, it evolves into a new species.
* Genetics- many organisms have similar genes and genetic codes, but are different species. Geographical distribution in more detail Geographical distribution means that each species starts off in the same environment and same location. Geographical distribution proves evolution because something will eventually happen to the environment, making the species unable to live there for any longer. Divergent evolution explains that every species begins in one location, and when something happens to that location (humans move in, urbanization, area dries up, vegetation dies, etc.), they move to all different environments of different climates and locations.
In each different area, the species adapts to the environment. After millions of years and many generations, the species has adapted so much that it turns into a new species. Depending on the environment, the species will adapt differently and evolve into different species. These species often remain related, but they are no longer the same. For example, species A is a type of bird living in the forest. This bird is most likely green or brown to camouflage with the environment. These birds eat leaves from the trees. One day, the humans decide to cut down all the trees.
The vegetation is all gone and the birds have nothing left to eat. They must move to another location. Half of species A move to the desert and half move to the arctic. The birds that move to the desert adapt to that environment by changing the colour to a lighter brown or beige to camouflage and start eating meat from decomposing animals. Meanwhile, the birds that move to the arctic turn white to camouflage and begin to eat fish.
This species has move to two different areas, and the birds in each area have evolved. Over millions of years, the birds changed into different species. The birds that live in the desert are now known as species B and the birds that live in the arctic tundra are now referred to as species C. These two birds are still similar in structure and still share common qualities, but they are different species. We consider them related species, but we no longer consider them the same species.