23 Febrero 2017 12:12
Scientists have found strange prehistoric microbes living in giant selenite crystals deep inside a cave in Chihuahua, Mexico. Researchers suspect that the organisms have been living there for 50,000 years.
The cave, part of the Naica Mine – from which lead and silver are extracted – is located 300 metres beneath the surface. It looks beautiful, but for living creatures the cave is hell. With temperatures ranging between 45ºC and 65ºC, and humidity levels hitting 99%, its atmosphere is extremely inhospitable to life.
And yet, in pockets of liquid found inside some of the selenite columns, ancient and remarkable organisms have managed to survived. After extracting the organisms from the cavities, researchers from the NASA Astrobiology Institute have now woken them up from their dormant state and analysed them.
The organisms consist of 40 different strains of microbes and viruses that have survived thanks to iron and magnesium. Living in darkness, far beneath the surface and away from sunlight, the microbes can't photosynthesise. Instead, they perform chemosynthesis, using minerals like iron and sulphur in the giant gypsum crystals.
The microbes found are unlike anything in the scientific record. Researchers had previously found life inside the walls of the cave during a 2013 expedition to Naica. But the organisms found in the crystals themselves have a very different DNA. Analysis has revealed that their genetic information differs from that of their closest relatives by 10%: a distance as large as that which separates humans from fungi.
Researchers suspect that the creatures are between 10,000 and 50,000 years old. If this estimate is confirmed, it would mean that these microbes possess an incredible capacity to resist for thousands of years in the most inhospitable habitats – possibly even in outer space.
The other big surprise is that scientists were able to revive the organisms and grow cultures from them in the lab. 'It was laborious. We lost some of them – that's just the game. They've got needs we can't fulfil,' Penelope Boston, director of the study, told The Telegraph.
The research team intends to continue studying these mysterious microbes. Life in this cave may help us get a better understanding of life in outer space.
[Via Science Alert]