With no meal for 86 million years, and barely enough oxygen to sustain metabolism, can a single-celled organism really be considered alive? Yes, but only just, according to a new study. A microbial community buried under the ocean floor since the mid-Jurassic era is still hanging on. Their tenacity could pose some interesting questions for the hunt for alien life.
Plenty of microbes live beneath ocean sediments - about 90 per cent of the planet's unicellular organisms are found there, and they've long been subjects of study among biologists interested in extreme environments. Hans Røy and colleagues wanted to dig even deeper to examine the most barren places, where food supplies are scarce or nonexistent and where oxygen barely reaches.