I discuss a new scenario called Hylogenesis (hylo=matter) that
explains the baryon and dark matter densities of Universe in a unified
way. Early universe dynamics generate the baryon asymmetry and an equal
antibaryon asymmetry in a GeV-scale hidden sector. The hidden antibaryons
are dark matter. Our model has a striking signature that dark matter can
annihilate baryons, mimicking nucleon decay. I discuss the effective
nucleon decay rates and implications for existing nucleon decay searches.