In my Biology curriculum, natural selection and evolution are heavily stressed. To help students understand these concepts, I use the HHMI BioInteractive on the Making of the Fittest. The lesson plan on Rock Pocket Mice is very good. My 9th grade Biology students enjoy learning about these furry little mice and how a change in the environment has changed their allele frequency over time. There’s a pre-test as well as a post-test to gauge student’s understanding.
The Botany of Desire is a book written by Michael Pollan. PBS has created a documentary based on the book to highlight how human have artificially selected for specific traits in plants for agriculture purposes.
There are interactive activities on the websites with lesson plans on the website. http://www.pbs.org/thebotanyofdesire/