Arctic ice caps thawing under the effects of climate change are revealing organisms that have been frozen for hundreds of years.
Scientists are discovering bacteria and multicellular animals that were long thought to be extinct, reports the National Post.
Researchers studying Teardrop Glacier on Canada's Ellesmere Island found a tuft of moss that had become frozen during the global cold snap from 1550 to 1850, known as the Little Ice Age.
From 1850, it had been encased under 30 metres of ice until 2009 when scientists discovered the tuft of the species Aulacomnium turgidum freed from its icy tomb.
While the moss was faded and torn, its deep colouring suggested signs of life.
'You wouldn't assume that anything buried for hundreds of years would be viable,' said evolutionary biologist Catherine La Farge, of the University of Alberta.
In 2009, her research team was searching Teardrop Glacier for plant matter ejected by the melting glacier. They found centuries-old moss tufts.
'The material had always been considered dead. But by seeing green tissue, 'I thought, 'Well, that's pretty unusual,' said La Farge.
When the moss samples were re-planted with nutrient rich soils in laboratory conditions about a third of them flourished. With plenty of light and warmth, they grew new shoots and leaves.
The moss showed few ill effects of being deep frozen over centuries.
Scientists have found the ways mosses survive being frozen. They dry out when temperatures suddenly plummet, avoiding the threat of ice forming in their tissues. And if parts of the plants do suffer damage, some cells can split and reform into various tissue types that make up a complete moss.
With these adaptations, mosses have a better chance than other plants of surviving long-term freezing, researchers believe.
Peter Convey, an ecologist with the British Antarctic Survey, was part of a research team that discovered a 1,500-year-old moss buried a metre under Antarctic ice.
'The permafrost environment is very stable,' he said.
The regrowth of mosses after hundreds of years suggests permafrost and glaciers are far from being graveyards for organisms. They may instead help multicellular life resist ice ages.
And as warming temperatures caused by climate change melts permafrost in the Arctic and Antarctic, the surviving plant life will be set to dominate the polar landscapes.
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