What is the driving force behind evolution?

Related questions

1. How are fossils used as evidence for evolution?
2. Is gravity a fact?
3. How did black skin come about?
4. Why do some species evolve while others go extinct?
5. Who was the first person on the earth?
6. How was Earth created?
7. How does gene flow work?
8. What evolved into humans?
9. Why is natural selection important to our lives?
10. What exactly is evolution?

Tags

1. #important
2. #variations
3. #occurs
4. #selection
5. #different
6. #secondary
7. #driving
8. #types
9. #evolution
10. #sometimes
11. #mutation
12. #because
13. #created
14. #others
15. #better
16. #force
17. #course
18. #natural