De-extinction projects today are piecemeal, trying to stitch genes from frozen tissue into living relatives. But what if we could resurrect not just the body, but the context? What if we could bring back an entire lost world? This is the mission of the Paleo-World Model: a simulation of extinct ecosystems so accurate it becomes the blueprint for their physical restoration.The model starts with the fragments: fossil records, pollen samples, climate data from ice cores, and the genomes of the closest living relatives. It doesn't just place a sabre-tooth tiger in a forest. It simulates the complete ecological dance. It models the predator-prey dynamics between the tiger and giant ground sloths. It simulates the grazing patterns of mammoth herds and how they shaped the grassland ecology. It calculates the nutrient cycles, the seasonal migrations, the symbiotic relationships with extinct flora.This model serves two profound purposes. First, it's a scientific oracle. We can ask it: 'Why did the North American megafauna go extinct?' and run simulations with different variables (human hunting, climate change, disease) to see which scenario fits the fragmentary evidence. Second, it's a restoration guide. If we were to genetically engineer proxy species, the model tells us how many to introduce, where, and when, to achieve a stable, functioning ecosystem. It's the ultimate recipe for a lost world.The ambition is a Pleistocene Park—a vast, controlled reserve where a simulated ecosystem becomes real. But the model's most heart-breaking output might be the realization of irreversible loss. It might show us that some ecosystems were so unique, so dependent on keystone species with no modern analogue, that they can never be truly revived. The model becomes a museum of ghosts we can visit but never touch.My controversial take is this: The Paleo-World Model will force a brutal ethical reckoning with the finality of extinction. We will be able to simulate, with uncanny vividness, the sights and sounds of lost worlds, making their absence feel like a fresh amputation. This will create a powerful, melancholic cultural movement—Restorationism—that views the Anthropocene not as an age, but as a crime scene, and sees these simulations as the first step towards making reparations to the planet. But it will also reveal that some wounds are too deep; some silence, once imposed, can never be broken by anything but a perfect, and forever unattainable, dream."This has been The World Model Podcast. We don't just study the past—we build the archives for worlds that have vanished, and the blueprints for worlds that might return. Subscribe now.