Nice introduction to Genetic Genealogy

I ran across a nice introduction on the Internet for Genetic Genealogy while preparing for the class that I have to teach this upcoming weekend for RootsFest. The text is straightforward and the graphics are great- I think even middle school students could understand the complex subject matter with this website, so I encourage you to check it out if this is an interest of yours:

http://www3.nationalgeographic.com/genographic/index.html

Check out the bottom left "Genetic Overview" link.