Miles below us, deep within Earth’s crust, life is astir. Organisms there are not the large creatures typically envisioned when thinking of life. Instead, thriving there are microbes, the smallest and oldest form of life on Earth. Although the biological diversity of these deep biosphere microorganisms may surpass that of the more familiar surface biosphere, much about them is still unknown, including the origin of the organic compounds they consume.
via Deep biosphere research points to new methods for recovering petroleum.
