# Irreducible Complexity > **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 / Intelligent Design Debate **Doc Type:** Canonical Wiki Node **Maturity:** Developed ## Definition Irreducible complexity is an intelligent-design argument claiming some multipart biological systems could not function after removal of any part and therefore could not evolve stepwise. ## Nexus Context Avida experiments showed that complex logical functions can evolve through differently useful intermediates, but the paper’s precise result should not be expanded into a universal refutation without argument. ## Evidence Boundary The scientific issue concerns evolutionary pathways and evidence; legal findings at Kitzmiller additionally addressed whether intelligent design is science for public-school purposes. ## Relationships [[wiki/Avida|Avida]], [[wiki/Robert Pennock|Robert Pennock]], [[wiki/Kitzmiller v. Dover|Kitzmiller v. Dover]], [[wiki/Evidence Boundary|Evidence Boundary]] ## Sources / Provenance - Lenski et al. (2003); Kitzmiller v. Dover opinion (2005).