South African bacteria

Scientists discovered bacteria in South African gold mines that lives in water miles below the surface completely without sunlight. Scientists refer to species that live in extraordinarily harsh climates as extremophiles (140 degrees Fahrenheit in this case). This bacteria eats food from the radioactive decay of the surrounding rocks. Since it lives without sunlight, it lives without oxygen, it lives without any other organisms in its food chain, since it lives when all reasons say it should not, it lends hope to the pursuit of life on other planetary bodies.

On the other hand, it is the only organism in the environment. Without any biodoversity, competition, the lifeform is at risk for wholesale extinction. For example it lacks the ability to resist oxygen so a change in to the environment could elimate all life entirely. In other words, the existance of life where none should be is amazing but it hangs on precariously.

For more information, see the article published in the October 10th 2008 Science magazine titled "Environmental Genomics Reveals a Single-Species Ecosystem Deep Within Earth": http://www.sciencemag.org/cgi/content/abstract/322/5899/275

[Extract]
DNA from low-biodiversity fracture water collected at 2.8-kilometer depth in a South African gold mine was sequenced and assembled into a single, complete genome. This bacterium, Candidatus Desulforudis audaxviator, composes >99.9% of the microorganisms inhabiting the fluid phase of this particular fracture. Its genome indicates a motile, sporulating, sulfate-reducing, chemoautotrophic thermophile that can fix its own nitrogen and carbon by using machinery shared with archaea. Candidatus Desulforudis audaxviator is capable of an independent life-style well suited to long-term isolation from the photosphere deep within Earth's crust and offers an example of a natural ecosystem that appears to have its biological component entirely encoded within a single genome.