title: Life, geology and snowball Earth.
authors.affiliation: Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, USA. schrag@eps.harvard.edu
authors.forename: D P
authors.initials: DP
authors.lastname: Schrag
authors.forename: P F
authors.initials: PF
authors.lastname: Hoffman
mesh_terms: D002245:Carbon Dioxide; D003081:Cold Climate; D018534:Earth, Planet; D056890:Eukaryota; D005057:Eukaryotic Cells; D005615:Freezing; D009792:Oceans and Seas; D010788:Photosynthesis
chemical_list: D002245:Carbon Dioxide