Chris Reinhard in the Proceedings of the National Academy of Sciences


Chris Reinhard, assistant professor in Earth & Atmospheric Sciences / Georgia Tech and his team modelled how oxygen entered oceans from the atmosphere and from aquatic sources, and how oceans might have shuffled it around during the mid to late Proterozoic Eon. That was 0.6 to 1.8 billion years ago, when the Earth’s atmosphere had only fraction of the breathable oxygen it does today.

In the model, the ocean didn’t share and share alike, but instead pushed dissolved O2 into areas of concentration that shifted starkly as corresponding concentrations in the atmosphere rose.

That has implications for the way scientists think about the timeframe for animal evolution on Earth and for future estimates for the probability of complex life on exoplanets.

The results and detailed modeling parameters were published on Monday, July 25, 2016, in the Proceedings of the National Academy of Sciences. The research was funded by the National Science Foundation and the NASA Astrobiology Institute.

Excerpt from the Georgia Tech press release: Before Animals, Evolution Waited Eons to Inhale by Ben Brumfield


Additional press coverage of the paper can be found at Christian Science Monitor and The Daily Mail


Photo Left:  Chris Reinhard by Ben Brumfield / Georgia Tech

Photo Right:  Earliest animals evolved in the mid to late Proterozoic Eon and lie deep in the fossil record. Depicted in the photo is an example of the Pteridinium genus. Credit: Douglas Erwin / National Museum of Natural History


Dr. Chris Reinhard’s background is originally in evolutionary biology, but his past and current research is best characterized as falling under the label of 'deep time biogeochemistry' — He is fascinated and astonished by the observation that our planet has come to support a pervasive biosphere, and seek to reconstruct how we got here. This involves combining techniques from aqueous geochemistry, geology, and biogeochemical modeling in an effort to reconstruct Earth surface environments as they have changed over long timescales through Earth's deep history and how this evolution has been coupled with the evolution of microbial and macroscopic life. He received his Ph.D. in Earth Sciences from the University of California, Riverside in 2012 and joined Georgia Tech as an Assistant Professor in 2014.