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Looking Back in Time explores human evolution through an engineer’s lens, and the references listed here provide the foundation for that discussion.

To support the main article, these companion cheat sheets also draw on the same sources:
–  Nerd Cheat Sheet: Earth History Data
–  Nerds Cheat Sheet: Brain Functionality
–  Nerds Cheat Sheet: Food for Thought

(Fact check and references generated by ChatGPT as part of the editing process.)

1. Stegosaurus and Jurassic dating
   Maidment, S.C.R. & Barrett, P.M. (2011). A new specimen of Stegosaurus from the Upper Jurassic Morrison Formation of Wyoming, USA. Acta Palaeontologica Polonica.
   → Confirms Stegosaurus lived in the Late Jurassic, ~155–150 million years ago.
   
2. Duration of stegosaurs
   Galton, P.M. & Upchurch, P. (2004). Stegosauria. In Weishampel, D.B. et al. (eds.), The Dinosauria (2nd ed.). University of California Press.
   → Stegosaurid dinosaurs persisted for ~10 million years as a group.
   
3. Earth history and microbial dominance
   Knoll, A.H. (2015). Life on a Young Planet: The First Three Billion Years of Evolution on Earth. Princeton University Press.
   → Complex multicellular life appeared only in the last ~600 million years; for most of Earth’s 3.8 billion years, life was microbial.
   
4. Elephant brain size
   Shoshani, J., Kupsky, W.J., & Marchant, G.H. (2006). Elephant brain: Part I: Gross morphology, functions, comparative anatomy, and evolution. Brain Research Bulletin, 70(2–3), 124–157.
   → Average elephant brain mass ~4,783 g, based on 7 specimens (African and Asian).
   
5. Cat brain mass
   Popesko, P., Rajtová, V., & Horák, J. (1992). A Colour Atlas of the Anatomy of Small Laboratory Animals. Wolfe Publishing.
   → Domestic cat brain weighs ~25–30 g, consistent across sources.
   
6. Human brain mass and energy consumption
   Clarke, D.D. & Sokoloff, L. (1999). Circulation and energy metabolism of the brain. In Basic Neurochemistry: Molecular, Cellular and Medical Aspects (6th ed.). Lippincott-Raven.
   → Human brain is ~1,300–1,400 g and consumes ~20% of resting metabolic energy.
   
7. Queensland Brain Institute outreach
   Queensland Brain Institute, University of Queensland. How your brain makes and uses energy.
   → Confirms public-science figure that the brain consumes ~20% of energy intake.
   
8. Bird intelligence and neuron density
   Olkowicz, S. et al. (2016). Birds have primate-like numbers of neurons in the forebrain. PNAS, 113(26), 7255–7262.
   → Crows, parrots, and other birds achieve high cognition with small brains due to neuron packing density.
   
9. Human brain wattage
   Herculano-Houzel, S. (2016). The Human Advantage: A New Understanding of How Our Brain Became Remarkable. MIT Press.
   → Human brain runs on ~20 W, similar to a dim lightbulb.
10. AI energy costs
    Patterson, D. et al. (2021). Carbon emissions and large neural network training. arXiv:2104.10350.
    → Large-scale AI models require thousands of watts during training and inference; comparison to brain efficiency is valid.
    
11. Triune brain model caveat
    MacLean, P.D. (1990). The Triune Brain in Evolution: Role in Paleocerebral Functions. Springer.
    → Introduced the brainstem–limbic–neocortex framework. Modern neuroscience critiques it as oversimplified, but it remains useful for conceptual illustration.
    
12. Evolutionary mismatch and psychology
    Nesse, R.M. & Williams, G.C. (1994). Why We Get Sick: The New Science of Darwinian Medicine. Vintage.
    → Explores how traits once adaptive in tribal settings (fear, anxiety, bonding) can clash with modern environments

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📖 Series Roadmap

1. Forward: A Little Background
2. Introduction: Action, Reaction, and the Human Paradox (16.09.2025)
3. Looking Back in Time: The Development of the Human Brain (23.09.2025)
4. Abstract Senses: Enhancing the way we see the world outside (30.09.2025)
5. Bias as a Concept & Climbing the Stairs: Pattern Recognition & Everyday Tasks (07.10.2025)
6. Abstract Feelings and Abstract Senses (14.10.2025)
7. Motivation (04.11.2025)
8. The Social Knowledge Base (11.11.2025)
9. Potential (18.11.2025)
10. The Subliminal Way We Go Through Life (26.11.2025)
11. Taking Responsibility (02.12.2025)
12. Fishing for Complements (22.12.2025)
13. Peter and Fermi (22.12.2025)

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