Breathable Atmospheres on Exoplanets: An Evolutionary, Biochemical, and Gaia-Inspired Perspective

To the point

Breathable atmospheres on alien worlds arise when oxygenic metabolism becomes widespread and ecosystem feedbacks regulate atmospheric chemistry, so habitability depends on biology’s evolutionary age rather than Earth-like geology or a host star, a view supported by James Kasting and Tim Lenton.

The Inevitable Gas: Oxygen, Astrobiology, and Why Alien Worlds May Have Breathable Atmospheres
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The Inevitable Gas: Oxygen, Astrobiology, and Why Alien Worlds May Have Breathable Atmospheres

Why Evolution May Produce Oxygen-Rich Atmospheres on Alien Worlds