Zipping up and down through the galaxy might, though
Out-of-This-World Hypothesis: Cosmic Forces Control Life on Earth
http://bcast1.imaginova.com/t?r=2&ctl=F959:4A48D
The rise and fall of species on Earth might be driven in part by the undulating
motions of our Solar System through the Milky Way’s galactic plane, scientists
say.
