Response to Comment on "Molybdenum Isotope Evidence for Widespread Anoxia in Mid-Proterozoic Oceans"

Relating changes in Mo isotope signatures preserved in the geologic record to changes in the extent of seafloor anoxia is not a trivial exercise. We previously presented and interpreted new Mo isotope data as indicating expanded anoxia in mid-Proterozoic oceans, potentially reaching global extent. Ling et al. challenge our conclusions, arguing that the data are not consistent with widespread anoxia. We stand by our original interpretation but welcome the opportunity to clarify and expand on those conclusions, particularly in view of the potential importance of ocean redox change for biological evolution.