Science Web Surf (7th): Adaptation of a Species

Part 1: What is Genetic Variation?

http://learn.genetics.utah.edu/content/variation/

Part II: Got Germ-X?

http://www.ncbi.nlm.nih.gov/pubmed/9667796

Part III: Natural Selection

http://www.pbs.org/wgbh/evolution/darwin/origin/index.html

Part IV: Artificial Selection

http://www.learner.org/courses/essential/life/session5/closer1.html