Why do classification systems change over time?
a. scientists find new evidence in their studies.
b. scientists use old methods of classification.
c. scientists repeat experiments and find no changes.
d. scientists find similar evidence to previous work.

Sarah and john are having a discussion on genetic diversity. sarah believes that it happen over a long period of time. john it happens immediately. who is correct? a. sarah is correct because genetic diversity occurs over a long period of time. b. john is correct because genetic diversity occurs immediately. c. both are correct because genetic variation can occur or long period of time. d. neither are correct because genetic diversity occurs over any period of time