# Biosphere > **Machine-Evolution Nexus:** [[articles/Digital Darwinism and the Invisible World of Machine Evolution|Digital Darwinism and the Invisible World of Machine Evolution]] places this node within the history and governance of substrate-independent evolution. **Domain:** Earth Systems / Evolution **Doc Type:** Canonical Wiki Node **Maturity:** Developed ## Definition The biosphere is the planetary system formed by living organisms and their interactions with atmosphere, oceans, land and biogeochemical cycles. ## Nexus Context Its long-running novelty, niche construction and major transitions provide the standard artificial-life systems have not yet reproduced at comparable open-ended scale. ## Evidence Boundary Calling a digital environment a biosphere is a strong claim. It should require persistent ecological closure, generativity and material-resource accounting, not merely many agents. [[wiki/Marsification|Marsification]] names a different threshold: the replacement of particular ambient biospheric services by engineered ones. A city can become dependent on manufactured water, food, thermal control and sensing without Earth ceasing to possess a biosphere. [[articles/The Last Migration Will Not Be Human|The Last Migration Will Not Be Human]] depends on this distinction and explicitly rejects literal near-term atmospheric loss. ## Relationships [[wiki/Open-Ended Evolution|Open-Ended Evolution]], [[wiki/Systems Ecology|Systems Ecology]], [[wiki/Niche Construction|Niche Construction]], [[wiki/Spaceship Earth|Spaceship Earth]], [[wiki/State-Dependent Catastrophe|State-Dependent Catastrophe]] ## Sources / Provenance - Earth-system science and evolutionary biology. ## Simple Reminders, Quotations, and Thoughts > “When we discover separate origin life, we will hit the jackpot. It will truly be made of a different flesh. Biochemists will be fascinated to learn how life functions such as energy capture, information storage and catalysis can be carried out by materials different from the life we know.” > **— Robert Shapiro**, *2009 Edge Annual Question, response passage* [[reminders/Evolution/Separate-Origin Life Could Reveal Another Biology by Robert Shapiro|Separate-Origin Life Could Reveal Another Biology by Robert Shapiro]] > “I cannot imagine any single discovery that would have more impact on humanity than the discovery of life outside of our solar system. There is a human-centric, Earth-centric view of life that permeates most cultural and societal thinking.” > **— J. Craig Venter**, *2011 Edge Annual Question, response passage* [[reminders/Evolution/Life Beyond Our Solar System Would Transform Humanity by J. Craig Venter|Life Beyond Our Solar System Would Transform Humanity by J. Craig Venter]]