|The tardigrade can survive 30 years without food - half its lifetime CREDIT: EYE OF SCIENCE/SPL/SOLENT|
Boil them, deep-freeze them, crush them, dry them out or blast them into space: tardigrades will survive it all and come back for more
The tiny tardigrade has been named the world’s most indestructible species after scientists discovered it is the only creature that will survive until the Sun dies.
Although cockroaches are traditionally seen as Earth’s most resilient species, the eight-legged microbeasts are actually far hardier and will continue to thrive for around 10 billion years, come hell or high water, Oxford University has found.
Tardigrades, which are also known as space bears or moss piglets, are able to survive for up to 30 years without food or water and endure temperature extremes of up to 150 degrees celsius, the deep sea and the frozen vacuum of space.
Not only does it suggest that tardigrades will survive long after humans have died out, but it gives hope that life could exist on even the most barren and hostile planets.
“Life on this planet can continue long after humans are gone,” said Dr Rafael Alves Batista, of the Department of Physics at Oxford University.
“Tardigrades are as close to indestructible as it gets on Earth, but it is possible that there are other resilient species examples elsewhere in the universe.
“In this context 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.”
The water-dwelling micro animals can live for up to 60 years, and grow to a maximum size of 0.5mm. The only real threat to their existence would be from an apocalyptic event which would cause Earth’s oceans to boil away. But the scientists discovered that there are only a dozen known asteroids and dwarf planets with enough mass to cause the oceans to boil if they struck the Earth and none are on a collision course with our planet, Smaller space rocks would not harm tardigrades.
Destructive explosions of electromagnetic energy known as gamma-ray bursts which are thought to be caused by neutron stars colliding or the formation of black holes could also be a threat to the little creatures, but again non could occur close enough to wipe out the species.
Dr David Sloan, Co-author and Post-Doctoral Research Associate in the Department of Physics at Oxford University, said: “To our surprise we found that although nearby supernovae or large asteroid impacts would be catastrophic for people, tardigrades could be unaffected. Therefore it seems that life, once it gets going, is hard to wipe out entirely.
“Huge numbers of species, or even entire genera may become extinct, but life as a whole will go on.”
In highlighting the resilience of life in general, the research broadens the scope of life beyond Earth, within and outside of this solar system.
Professor Abraham Loeb, co-author and chair of the Astronomy department at Harvard University, said it proved that life could survive in even the harshest environments, such as beneath the surface of Mars, or on the moons of Europa and Enceladus.
“Organisms with similar tolerances to radiation and temperature as tardigrades could survive long-term below the surface in these conditions,” said Prof Loeb.
“The subsurface oceans that are believed to exist on Europa and Enceladus, would have conditions similar to the deep oceans of Earth where tardigrades are found, volcanic vents providing heat in an environment devoid of light.”
The research was published in the Scientific Reports.