arXiv:0901.3173 [pdf] Title: Whilst this Planet Has Gone Cycling On: What Role for Periodic Astronomical Phenomena in Large Scale Patterns in the History of Life? Authors: B.S. Lieberman, A.L. Melott (University of Kansas) Comments: 39 pages, 5 figures, to be published in the Biosphere volume of the International Year of Planet Earth Series, J. Talent, Ed Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Galaxy Astrophysics (astro-ph.GA); Biological Physics (physics.bio-ph); Geophysics (physics.geo-ph); Populations and Evolution (q-bio.PE) One of the longstanding debates in the history of paleontology focuses on the issue of whether or not there have been long term cycles (operating over tens of millions of years) in biodiversity and extinction. Here we consider the history of this debate by connecting the skein from Grabau up to 2008. We focus on the evidence for periodicity that has emerged thus far, and conclude that there is indeed some evidence that periodicity may be real, though of course more work is needed. We also comment on possible causal mechanisms, focusing especially on the motion of our solar system in the Galaxy. Moreover, we consider the reasons why some scientists have opposed periodicity over the years. Finally, we consider the significance of this for our understanding of evolution and the history of life.