Ideal homes

摘要

What is an extreme environment? In the deepest parts of the ocean, pressure can reach 1100 atmospheres, enough to crush not just us, but all the fish familiar to us as well. These benthic waters are also utterly dark, and temperatures a chilly 2 and 3 ℃. Surely this qualifies as an extreme environment? Well, perhaps not. David Wharton points out that the deep sea represents 75 per cent of the biosphere. This sunless, frigid place is therefore "normal" by many definitions and far from empty of life. Extreme depends on where you stand, says Wharton, and it is a dynamic, evolving concept.