How do we know what the Earth was like billions of years ago? And where did all the oxygen come from? Spoiler alert: it's microbes! This week I speak with Dr. John Encarnacion about the Great Oxygenation Event (GOE) that changed our planet forever and is the reason we breathe today. We talk about the detective work of geologists and the evidence found in rocks that teaches us about ancient biological and geological processes!

Dr. John Encarnacion, PhD is a professor at Saint Louis University where he studies plate tectonics and hard rock geology. You can learn more about his work on his website and read his publications on Google Scholar. He is also an amazing science communicator and you can follow his fun geology page on Instagram: @a_geologist.

For more info on microbes and to follow updates of this podcast, find @couch_microscopy on Instagram, @CouchMicroscopy on Twitter, or visit www.couchmicroscopy.com/store for merch!

Music is "Introducing Cosmic Space" by Elf Power and "Vorticella Dreams" by L. Felipe Benites.

The views and opinions expressed on this program are those of the host and guests and do not reflect the views of any institution.