James Bradley in The Guardian:
The discovery of animals around hydrothermal vents has led to a dramatic broadening of our understanding of the sorts of environments in which life can survive. This has significant implications for the search for extraterrestrial life – if life thrives in such environments on Earth, it is plausible it might flourish in similar conditions in the oceans of ice moons such as Enceladus, which orbits Saturn. It has also shifted assumptions about where life on Earth began: perhaps it was not in a shallow pool, but somewhere in the depths of the primordial sea. In other words, the deep ocean might not be a place of death and forgetting, but rather the birthplace of life on our planet.
More here.