We can edit genes now, but why does the human brain still mistake thirst for hunger 70% of the time? Is this an unchangeable evolutionary fossil in our DNA, or are we just not wired for the filtered, structured water we drink today?
It’s neither a gene-editing failure nor a “structured water” mismatch — it’s a neural efficiency trade-off. Thirst and hunger are regulated by overlapping hypothalamic circuits (especially in the arcuate nucleus), and both are influenced by ghrelin, angiotensin II, vasopressin, dopamine, and circadian rhythm. Mild dehydration often produces fatigue, irritability, or low energy — signals the brain historically interpreted as energy deficit, not fluid deficit. In ancestral environments, food and water were often consumed together, so separating the signals with precision wasn’t evolutionarily necessary.
The “70% mistake” isn’t a hard biological constant, but it reflects modern context: processed foods, high sodium intake, constant availability, and eating by schedule rather than by homeostatic cues. Gene editing wouldn’t solve this because it’s not a broken gene — it’s overlapping regulatory architecture optimized for survival, not for filtered-water convenience. The brain prioritizes caloric security over hydration precision because, evolutionarily, starvation was deadlier than mild dehydration.
