Fact 1: Evolution is a change in the characteristics of living things over time.

Fact 2: Evolution relies on random chance acts to cause mutations.

Given the two facts above, answer the question "What causes changes in characteristics of living things over time?" with the following options: 
- mutations
 - science
 - parents
 - environment
 - light energy
 - news
 - alleles
 - animals


 

 mutations        