Adaptation to the envrionment is what produced the massive variance of life upon earth, if a species was too cold it evolved fur or blubber, in this sense every environment can be considered extreme to anything not adapted to it. If a person was to take an elephant and leave it in the polar icecaps ,it wouldn’t survive for very long. In the same fashion a penguin would not be too impressed with a jungle.
However, for a environment to be tuely extreme it leaves no room for middle ground. A species either survives and prospers or doesn’t last more than a few seconds. And when it comes to the deep sea, there is no other environment that come’s close to the problems encountered in other environments. No light, 1,500 atmospheres of pressure and scolding hot temperatures surrounded by freezing cold temperatures, quite a problem indeed. But yet like the rest of earth we find life not only surviving but prospering.
So why can these organisms tolerate these massive problems? What adaptions do they have to pressure, temperature and no light? This is what is about to be explored by examining these creatures.