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The Ādam Paradox Hypothesis 83
6. The Synchrony Problem: Retrospective Determinism
Genetics (My), demography (kyr), and climate (20–100k cycles) are retro-fit to
meet at ~70kya. This neat alignment is more descriptive than explanatory — a
post hoc narrative.
7. The Gradualism Contradiction: A Saltation Pattern
The record shows silence → sparks → sudden, irreversible ignition post-70kya
— a saltation inconsistent with strict gradualism. Even cautious defenders
concede a “rapid reconfiguration” (d’Errico & Stringer, 2011).
The Improbability of Convergent Evolutionary Ignition
Genomic loci implicated in symbolic cognition.
1.Iconic “Switch” Genes — FOXP2 (speech motor control/sequencing;
Enard et al., 2002; Konopka & Roberts, 2016); HAR1 (cortical layering;
Pollard et al., 2006); SRGAP2C (delayed spine maturation; Dennis et al.,
2012).
2.Human-Specific Duplications — ARHGAP11B (expands basal
progenitors; Florio et al., 2015); NOTCH2NL (prolonged cortical
neurogenesis; Fiddes et al., 2018).
3.Brain Size Regulators — MCPH1, ASPM, CDK5RAP2 (Evans et al.,
2005).
4.Human Accelerated Regions —
~2,700 HARs active as brain enhancers
(Capra et al., 2013).
5.Epigenetic/Noncoding Regulation — retrotransposon impacts;
methylation/acetylation timing changes (Lander, 2011).
