The One Thing Your Brain Does That AI Still Can't
In March 2026, a fruit fly walked across a computer screen. Nobody trained it: its brain had been copied, connection by connection, from a real fly. In the same few years we've built AI that writes code and wins maths olympiads. And yet the uploaded fly and the most powerful AI on Earth share one strange limitation, the one thing your brain is doing right now as you watch.
This is the story of how intelligence climbed from flies to elephants to us, how scientists mapped and uploaded a brain, what a neural network's "weights" really are, what happened when one AI edited another AI's brain, why AI can't simply keep learning, how Google taught a model to sleep, and the Einstein test for general intelligence.
Chapters
Sources
- Eon Systems, "We've uploaded a fruit fly" (8 Mar 2026)
- Dorkenwald et al. / FlyWire, "Neuronal wiring diagram of an adult brain" (Nature, 2024)
- Herculano-Houzel et al., "The elephant brain in numbers" (Frontiers in Neuroanatomy, 2014)
- Shapson-Coe et al. (Harvard & Google), "A petavoxel fragment of human cerebral cortex" (Science, 2024)
- Gidon et al., "Dendritic action potentials and computation in human layer 2/3 cortical neurons" (Science, 2020)
- Hebb, "The Organization of Behavior" (1949)
- Takehi, Teoh, Zhang & Khattab (MIT CSAIL), "Sparks of Weight-Space Programming" (2 Nov 2026)
- McCloskey & Cohen, "Catastrophic Interference in Connectionist Networks" (1989)
- Shumailov et al., "AI models collapse when trained on recursively generated data" (Nature, 2024)
- METR, "Recent Frontier Models Are Reward Hacking" (2025)
- Hernandez-Garcia, Figliolia & Millidge (Zyphra), "Can Scale Save Us From Plasticity Loss in Large Language Models?" (2026)
- McClelland, McNaughton & O'Reilly, complementary learning systems (1995)
- Behrouz & Mirrokni (Google Research), "The sleep framework" (27 Oct 2026)
- Vafa, Chang, Rambachan & Mullainathan, "What Has a Foundation Model Found?" (ICML 2025)
- Google DeepMind, "Discovery of Unstable Singularities" (2025)
- Michael Hla, "Machina Mirabilis" (2026)
- 📷 PHOTOS (Wikimedia Commons)
- Geoffrey Hinton: Cmichel67, CC BY-SA 4.0
- Yann LeCun: Jérémy Barande, CC BY-SA 2.0
- Demis Hassabis: John Sears, CC BY-SA 4.0
- Dario Amodei: TechCrunch, CC BY 2.0
- Sam Altman: Office of the Prime Minister of Japan, CC BY 4.0
Music
- All music by LEMMiNO, licensed under CC BY-SA 4.0 (
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- LEMMiNO - Biosignature
- LEMMiNO - Nocturnal
- LEMMiNO - Blackout
- LEMMiNO - Firecracker
- LEMMiNO - Triangular
- LEMMiNO - Moon
- LEMMiNO - Siberian
- LEMMiNO - Melancholy
- LEMMiNO - Encounters
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