The diversity of human expression is the raw material of discovery. Generative artificial intelligence threatens this resource even as it promises to accelerate innovation, a paradox now visible across science, culture, and professional work. We propose a framework to explain this tension. AI systems compress informational variance through statistical optimization, and users amplify this effect through epistemic deference. We call this process the AI Prism. Yet this same compression can enable novelty. Standardized forms travel across domain boundaries, lowering translation costs and creating opportunities for recombination that we term the Paradoxical Bridge. The interaction produces a U-shaped temporal dynamic, an initial decline in diversity followed by recombinant innovation, but only when humans actively curate rather than passively defer. The framework generates testable predictions about when compression constrains versus amplifies creativity. As AI becomes infrastructure for knowledge work, managing this dynamic is essential. Without intervention, the conditions for recovery may not arrive.