Earth's last survivors are going to be water bears: study
Misha Gajewski, CTVNews.ca Staff
Published Friday, July 14, 2017 10:58AM EDT
Last Updated Friday, July 14, 2017 2:22PM EDT
Scientists have found Earth’s most resilient species, and it’s not the cockroach.
A new study, published in the journal Scientific Reports, determined that the tardigrade, an eight-legged micro-animal, will outlive us all.
“Tardigrades are as close to indestructible as it gets on Earth,” study co-author Rafael Batista, from Oxford University, said in a statement.
Paul Delaney, physics and astronomy professor at York University, told CTV News Channel that “there are a variety of different genetic traits that allow them to survive in these differing environments.”
The hardy microscopic animals, also known as water bears, are able to survive for up to 30 years without food or water. According to the paper, they can endure temperature extremes as low as -272 degrees Celsius and as high as 150 degrees Celsius. They can even survive the deep sea, the frozen vacuum of space and radiation levels comparable to more than 70 times the amount of radiation given to treat cancer.
In comparison, humans could be wiped out pretty easily.
“Without our technology protecting us, humans are a very sensitive species,” Batista said.
“Subtle changes in our environment impact us dramatically. There are many more resilient species on Earth. Life on this planet can continue long after humans are gone.”
While research has looked at the various ways human life will go extinct, very little academic work has looked at what it would take to extinguish all life on earth, according to the study.
The study’s researchers from Oxford and Harvard University came to the conclusion that the only thing to wipe out life on earth would be if the oceans boiled.
And according to them, there are three types of cataclysmic events that could make that happen: a large asteroid impact, a supernova and a gamma-ray burst.
But after careful analysis, the researchers concluded that all of these events were quite unlikely.
In the paper, they write that there are only a dozen known asteroids and dwarf planets with enough mass to boil the oceans, including Pluto. However, none of those objects cross the Earth’s orbit.
For a supernova to cause our oceans to boil the exploding star would need to be 0.14 light-years away, and the closest star to the sun is four light years away.
Finally, gamma-ray bursts are also too far away from earth to be an actual threat.
After ruling out the multiple end-of-the-world scenarios, the study concluded that the microscopic creatures will be around for at least 10 billion years and could survive all astrophysical catastrophes, since none would be strong enough to boil off the world’s oceans.
David Sloan, another co-author on the paper from Oxford University found this to be quite comforting.
“Huge numbers of species, or even entire genera may become extinct, but life as a whole will go on,” he said.
The researchers say this discovery also broadens the scope for extraterrestrial life.
“There is a real case for looking for life on Mars and in other areas of the solar system in general. If Tardigrades are earth's most resilient species, who knows what else is out there,” said Batista.