After thousands of years of mystery, Dr. STONE SCIENCE FUTURE has finally answered the big question: what caused humanity's petrification? The answer arrives in episode 36, and it's exactly as wild as the series has hinted at since the beginning—it was aliens, sort of.

The culprits are the Medusas themselves, sentient synthetic life-forms that traveled across space with a strange mission. From their perspective, death is the ultimate terror. Since they're vulnerable to oxidation (essentially rusting), they see corrosion as their equivalent of mortality. To combat this universal fear, they've become self-described "parasites" who roam the cosmos offering other species a gift: immortality through petrification. By turning organic beings into stone, the Medusas believed they were preserving life indefinitely and eliminating the possibility of death.

The theory sounds almost reasonable—until you realize the Medusas expected something in return. They assumed that when petrified beings learned about this "gift," their superior intellect would allow them to break free from stone form and willingly partner with their saviors. In exchange, humanity would provide diamond batteries to keep the Medusas powered indefinitely. It's a cosmic business transaction that makes a twisted kind of sense if you don't think about consent.

Here's where humanity becomes a cosmic disappointment: the plan failed spectacularly. Instead of brilliant minds rapidly awakening to embrace their new shiny metal allies, almost no one regained consciousness within the expected timeframe. The few exceptions—like Senku and Xeno—validates the Medusas' intelligence hypothesis, but by then it was too late. The aliens slowly rusted away in Earth's atmosphere while centuries passed, and most of petrified humanity either weathered into dust or became buried underground, taking modern civilization with them.

It's a darkly funny explanation that recontextualizes the entire series. Dr. STONE has always been about human ingenuity and scientific progress, and this reveal drives home just how exceptional Senku and the others truly are. Literally billions of humans failed the Medusas' intelligence test, but a handful of teenagers figured out how to rebuild civilization from scratch anyway.