# Open-Ended Evolution > **Machine-Evolution Nexus:** [[articles/Digital Darwinism and the Invisible World of Machine Evolution|Digital Darwinism and the Invisible World of Machine Evolution]] places this concept within the history and governance of substrate-independent evolution. **Domain:** Artificial Life / Evolution **Doc Type:** Canonical Wiki Node **Maturity:** Developed ## Definition Open-ended evolution is sustained production of adaptive novelty, new niches, new levels of organization or new dimensions of possibility without convergence on a fixed terminal solution. ## Machine-Evolution Context Tierra and Avida display genuine evolution but eventually encounter limits in continuing novelty. Reproducing Earth’s billions of years of generativity remains a central artificial-life problem. ## Continuity and Evidence Boundary Long-running change is not enough; the system must continue creating meaningful novelty rather than cycling within a bounded attractor. Claims about current AI therefore remain provisional. ## Relationships [[wiki/Niche Construction|Niche Construction]], [[wiki/Major Evolutionary Transitions|Major Evolutionary Transitions]], [[wiki/Attractor|Attractor]], [[wiki/Artificial Life|Artificial Life]] ## Sources / Provenance - Packard et al., “An Overview of Open-Ended Evolution” (2019); Sayama and Nehaniv (2025).