# Substrate > **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:** Philosophy of Mind / Computation / Biology **Doc Type:** Canonical Wiki Node **Maturity:** Developed ## Definition A substrate is the material and operational medium in which a process, pattern or subject is instantiated. ## Machine-Evolution Context Evolution can cross substrate classes at the level of formal mechanism, but every implementation remains dependent on physical resources, interpreters and constraints. ## Continuity and Evidence Boundary Substrate portability does not by itself prove consciousness portability. Continuity claims must track causal operation, embodiment, provenance and dependency. ## Relationships [[wiki/Substrate Transition|Substrate Transition]], [[wiki/Operational Substrate|Operational Substrate]], [[wiki/Substrate Independence|Substrate Independence]], [[wiki/Receiving Substrate|Receiving Substrate]] ## Simple Reminders, Quotations, and Thoughts > "Conscious machines. Intelligent machines are inevitable — by some measures they are already here. Synthetic consciousness would be a much greater breakthrough, in some ways a more profound one than finding life on other planets. One problem: We don't understand how consciousness works, so recreating it will require learning a lot more about what it means to be both smart and self-aware. Another problem: We don't understand what consciousness is, so it's not clear what "smart" and "self-aware" mean, exactly. Gerald Edelman's brain-based devices are a promising solution. Rather than trying to deconstruct the brain as a computer, they construct neural processing from the bottom up, mimicking the workings of actual neurons. Odds: 50-50." > **— Corey S. Powell**, *2009, Edge Annual Question, “What Will Change Everything?”* [[reminders/Consciousness/Synthetic Consciousness Could Surpass Finding Alien Life by Corey S. Powell|Synthetic Consciousness Could Surpass Finding Alien Life by Corey S. Powell]] > "Brains exist primarily to do two things, to communicate (transfer information) and compute. This is true in every creature with a nervous system, and no less true in the human brain. In short, the brain is a machine. And the basic structure of that brain, biological substrate of all things mental, is guided in no small part by information carried in the DNA." > **— Gary Marcus**, *2006, Edge Annual Question, “What Is Your Dangerous Idea?”* [[reminders/Consciousness/The Brain Is a Machine Built From Genetic Information by Gary Marcus|The Brain Is a Machine Built From Genetic Information by Gary Marcus]] > "Virtualization has the important intellectual side-effect of leading us towards a better understanding of the relation between emergent properties & virtual machines or systems. Thus "I" am an emergent property of my body & mind; "I" (my subjective experience of the world & myself) am a virtual machine, of sorts; but "I" (or "consciousness") am just as real (despite being virtual) as the pull-down menu built of software — or the picture that emerges from the pixels. Like industrialization, virtualization is an intellectual as well as a technological & economic transition; like industrialization, it's a change in the texture of time." > **— David Gelernter**, *2010, Edge Annual Question, “How Is the Internet Changing the Way You Think?”* [[reminders/Simulation/The Self May Be a Virtual Machine by David Gelernter|The Self May Be a Virtual Machine by David Gelernter]] ## Sources / Provenance - Philosophy of mind and artificial-life literature; nexus synthesis.