2. These different organisms then compete to survive and reproduce.
3. Those which are best able to survive and reproduce do so, and tend to leave the most offspring. This is called “natural selection.”
4. Over time, if some organisms survive and reproduce more than others, a species will "evolve."
- All organisms arose through the random process of mutation.
- All organisms arose and persist because of unguided natural selection, which can only select for actual beneficial mutations.
*Evolutionary theory says some reptiles also turned into birds.