Divers found thriving life at vents where sunlight never reaches the seafloor

In 1977, scientists diving to the Galápagos Rift in the submersible Alvin expected a barren seafloor near volcanic vents. Instead they found tube worms, clams, and shrimp thriving in total darkness, fed not by photosynthesis but by bacteria converting the vents' hydrogen sulfide into energy. It reset assumptions about where life can exist, on Earth or elsewhere.

— John B. Corliss et al., Submarine Thermal Springs on the Galápagos Rift — Science, vol. 203, 1979