This is just for fun. Guinness beer has a commercial explaining what drives evolution. For those with Quick Time go here: http://www.framestore-cfc.com/commercials/guinness_noitulove/amv_gune339_050_qt.mov
For those who don’t have Quick Time go here: http://www.youtube.com/watch?v=hv0HN2DCdCI&search=guinness