Evidence of evolution

Evidence of evolution consist of all historical and modern facts which confirm the theory of evolution. The three aspects which must be proven are first, that the various species of life have appeared gradually over the course of time (i.e., hundreds of millions of years); second, that all forms of life have a common ancestor (see common descent); third, that the cause of the first two aspects can be accounted for entirely by natural means (see theory of evolution by natural selection).

Creationism, particularly the religious idea generally called Young Earth Creationism, rejects the latter two aspects of evolution on Biblical grounds. Creationists approach the problem with the faith that God created every important form of life. Just over half of creationists agree with the first aspect of evolution (gradual appearance); see Old Earth Creationism.

The mainstream of physical science, however, has accepted all three aspects since at least the 20th century. Evolution proponents put forth evidence as follows.

Gradual appearance

Mainstream geologists and biologists believe that fossils show the body plans of dead animals and plants, and that these can be assign ages ranging from hundreds of thousands to hundreds of millions of years (see carbon dating). This evidence is disputed by Scientific Creationism, primarily on the premise that the Earth is less than 10,000 years old; mainstream scientists in turn reject "creation science" on the grounds that it begins with religious premises.