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

Fact 2: Almost all physical characteristics are genetic traits, inherited from parents.

Given the two facts above, answer the question "Evolution is a change in the genetic traits of living things over what?" with the following options: 
- universes
 - HIV
 - long
 - extinct organisms
 - dead things
 - time
 - H 2 O
 - years


 

      time   