by Karen G. Lloyd

The sediments underlying the world's oceans contain about a third of the total number of microbial cells on the planet. This is a vast biosphere, mostly comprised of deep branches on the tree of life that no one has yet figured out how to grow in a laboratory. Since growing microbes in a laboratory is the best way we can learn about them, this means that there's a lot of mystery about what makes this strange ecosystem tick. Probably the strangest thing about these ecosystems...