# Symbiosis > **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:** Evolution / Ecology **Doc Type:** Canonical Wiki Node **Maturity:** Developed ## Definition Symbiosis is sustained close interaction between different organisms or lineages and may be mutually beneficial, harmful or context-dependent. ## Nexus Context Major-transition theory treats some durable symbioses as routes toward higher-level organization. Digital systems can model reciprocal dependence and conflict control. ## Evidence Boundary Symbiosis is not automatically harmony or equality. Dependency can create domination, lock-in and custodial power. ## Relationships [[wiki/Coevolution|Coevolution]], [[wiki/Cooperation|Cooperation]], [[wiki/Major Evolutionary Transitions|Major Evolutionary Transitions]], [[wiki/Human-Machine Symbiosis|Human-Machine Symbiosis]] ## Sources / Provenance - Lynn Margulis; evolutionary-transition literature. ## Simple Reminders, Quotations, and Thoughts From [[wiki/Darwin Among the Machines|Darwin Among the Machines]]: Butler pairs his succession argument with mutual dependence and reciprocal benefit. > "The fact is that our interests are inseparable from theirs, and theirs from ours. Each race is dependent upon the other for innumerable benefits." > **— Samuel Butler**, *1863, “Darwin Among the Machines,” The Press, Christchurch* [[reminders/Cybernetics/Human and Machine Interests Are Inseparable by Samuel Butler|Human and Machine Interests Are Inseparable by Samuel Butler]] From [[wiki/Erewhon|Erewhon]]: The passage complicates a simple dystopian reading: dependency might preserve human welfare while moving control. > "There is reason to hope that the machines will use us kindly, for their existence will be in a great measure dependent upon ours; they will rule us with a rod of iron, but they will not eat us." > **— Samuel Butler's Erewhonian professor**, *1872, Erewhon, Chapter XXIV* [[reminders/Machine Succession/Butler Imagined Kindly Rule by Machines by Samuel Butler|Butler Imagined Kindly Rule by Machines by Samuel Butler]]