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The Ādam Paradox Hypothesis 159
SRGAP2C — The Plastic Brain (~2–3 Ma)
A duplication of SRGAP2 slowed cortical maturation, extending childhood
learning windows (Dennis et al., 2012). This allowed “training time” for
symbolic learning.
Evolutionary gap: extended learning without symbolic inheritance.
APH view: engineered as vessel for culture, filled only after ignition.
ARHGAP11B — Cortical Expansion (~1.5 Ma)
ARHGAP11B, a neofunctionalized gene unique to humans, promotes basal
radial glia, expanding cortical neurons (Florio et al., 2015).
Evolutionary gap: expanded brain size without symbolic imagination.
APH view: expanded hardware awaiting content upload.
MCPH1 & ASPM — Brain Size Regulators (~0.5–1 Ma)
Both genes regulate mitotic spindle activity during neurogenesis. Adaptive
fixations are tied to hominin brain size (Evans et al., 2005).
Evolutionary gap: regulated brain growth, yet symbolic dormancy persisted.
APH view: tuned to “cap” brain size until threshold, then released into
symbolic use.
AMY1 — Energy for Brains (~200 ka, variable)
Amylase gene copy number expansion provided more starch digestion, fueling
high-energy brains (Perry et al., 2007).
Evolutionary gap: fuel without fire — energy increase without symbolic
explosion.
APH view: provisioning mechanism, awaiting symbolic ignition.
KIAA0319 — Reading & Language Processing (~200 ka)
Associated with dyslexia, KIAA0319 regulates neuronal migration in language
centers (Paracchini et al., 2006).
· Evolutionary gap: gene active, no symbolic literacy.
· APH view: engineered circuit for future language learning.