Bacteria was asleep for 100 million years

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100 million year old bacteria alive under the seas

Bacteria 6 km deep inside the earth below the seas have been woken up after being in a state of semi-stasis for 100 million years. It is an extraordinary story reported today in The Times newspaper.

100 million year old bacteria alive under the seas

100 million year old bacteria alive under the seas. Illustration in the public domain and modified by AHR.

These microbes were on the floor of the oceans when dinosaurs roamed the earth and plesiosaurs (long-necked marine reptiles) swam above. They’ve been dug up by drilling 6 km beneath the sea. The scientist decided that there was just about enough oxygen down there to keep the bacteria alive. They were revived in a laboratory.


Plesiosaurs . In the seas 100 million years ago. Image: in public domain as assessed.

Fumio Inagaki said, “They are just sitting there over geological time. They can’t move, they can’t divide. They just slowly breathe oxygen, expelling the minimum amount of energy to maintain essential life functions like DNA repair. Fumio is from the Institute for Marine-Earth Exploration and Engineering in Japan.

They were extracted from the middle of the Pacific Ocean. There is little sediment there. Remarkably, only a few centimetres of sediment forms every million years. There is little to sustain life. Except for the sparse microbial communities, there is pretty well nothing there. When they dug out the core they saw something which look like bacteria and archea (single-celled organisms) and were surprised to note that they were alive. They started to feed them and they just woke up. Fumio thought it was amazing. I would agree with him.

The interesting aspect of this find is that it points to the possibility that life may exist in this form on Mars because bacteria can live like this for 100 million years 6 km below the surface locked into a planet’s crust. It is amazing. It also points to the possibility of life on other planets in a very basic form.

The study has been published in Nature Communications.