18-Feb-2017: Mexican caves hosts life dating back 50,000 years
Biologists unearth bizarre microbes trapped in crystals that survived on minerals under extremely punishing conditions.
In a Mexican cave system so beautiful and hot that it is called both Fairyland and hell, scientists have discovered life trapped in crystals that could be 50,000 years old. The bizarre and ancient microbes were found dormant in caves in Naica, Mexico, and were able to exist by living on minerals such as iron and manganese.
If confirmed, the find is yet another example of how microbes can survive in extremely punishing conditions on Earth.
The life forms of 40 different strains of microbes and even some viruses are so weird that their nearest relatives are still 10% different genetically. That makes their closest relative still pretty far away, about as far away as humans are from mushrooms.
The Naica caves, an abandoned lead and zinc mine, are half a mile (800 meters) deep. Before drilling occurred by a mine company, the mines had been completely cut off from the outside world. Some were as vast as cathedrals, with crystals lining the iron walls. They were also so hot that scientists had to don cheap versions of space suits to prevent contamination with outside life and had ice packs all over their bodies.
The research team could only work about 20 minutes at a time before ducking to a “cool” room that was about 100 degrees (38 Celsius).
This isn’t the oldest extreme life. Several years ago, a different group of scientists published studies about microbes that may be half a million years old and still alive. Those were trapped in ice and salt, which isn’t quite the same as rock or crystal.
The age of the Naica microbes was determined by outside experts who looked at where the microbes were located in the crystals and how fast those crystals grow.
It’s not the only weird life Ms. Boston is examining. She is also studying microbes commonly found in caves in the U.S, Ukraine and elsewhere that eat copper sulfate and seem to be close to indestructible.