al vents related to subsurface theory of origin of life? what makes the location and abiotic condition at HTV an example of how life evolved on earth?...

1. how are hydrothermal vents related to subsurface theory of origin of life?
2. what makes the location and abiotic condition at HTV an example of how life evolved on earth?
3. what kind of metabolism is supporting the growth of higher organism down there (crabs, fish, etc..)?
4. explain the difference when worms that live down there is supported in a different way that of crabs, fish, etc..

Thank you