- Tram Ho
Between 1550 and 1850, a sudden weather change named “Little Ice Age” increased the size of the Arctic ice sheets. In Canada’s Ellesmere island, the teardrop ice cream (Teardrop) in development has frozen a small moss bun.
From 1850, that moss bun lay under a layer of ice 30 meters thick while humans found antibiotics, on the moon and burned more than two trillion tons of fossil fuels.
Thanks to the latest findings, evolutionary biologist Catherine La Farge was present at Teardrop to find Aulacomnium turgidum. The moss bun is pale and tattered, but has a green color – a sign of life.
Stories of climate change often show the vulnerability of the Earth’s ecosystem. It became darker when the United Nations announced that about 1 million species of plants and animals were on the brink of extinction.
But for some special species, the melting and eternal ice caps are revealing a different story – an amazing biocompatibility story.
Arctic researchers are finding organisms, frozen and thought to die for millennia, that can bring life again. They range from simple bacteria to multicellular animals, and their persistence is making scientists surprised.
“You don’t think anything buried within hundreds of years is possible,” said La Farge, a moss researcher at the University of Alberta.
In 2009, her team was looking around Teardrop to find plants like this. The purpose of this work was to collect data on the vegetation that formed the surface of the island long ago.
“Material like this is often thought to be dead. But when I see blue tissue, I think it’s quite unusual. ” La Farge talked about the hundred-year-old moss bun she found.
After bringing these samples to Edmonton, she provided them with a nutrient-rich environment in the lab. Nearly a third of these trees have sprouted and sprouted leaves.
“We were quite surprised,” La Farge said. “This pile of moss shows very little negative impact from deep freezing.”
It is not easy to survive when completely frozen. The rugged stone crystals can rip off membranes and other important biological apparatus. Many trees and animals may succumb to the cold of the winter, waiting for the spring to be able to spawn or sprout.
The moss has chosen a more difficult path. They absorb moisture when the temperature falls suddenly, ignoring the potential of ice formation in the tissue. If the parts of the plant are damaged, some cells can divide and differentiate into all different types of tissue that include as a complete moss, like human embryonic stem cells .
Thanks to these adaptations, moss has a higher frequency than other plants to survive long-term freezing, according to Peter Convey, an ecologist from the British Antarctic Survey.
At the same time as La Farge’s moss revival project, Convey’s survey team announced that it had successfully restored another 1,500-year-old moss buried nearly 1m under the permafrost of Antarctica.
“This permafrost is very stable,” Convey said, emphasizing that perennial frozen soil can isolate moss from ground influences, such as annual freezing cycles or damaging radiation. damage to DNA.
The regrowth of the thousand-year-old moss suggests that glaciers or permafrost are not necessarily a graveyard for multicellular lives, but can instead help them endure ice ages. At the same time, due to the effects of global warming, gradually liberated organisms from that ice are ready to dominate the ecosystems in the poles.
Convey explains that when the ice melts on the surface of the soil, the tree gradually invades this new terrain “from elsewhere,” through the winds that carry spores. Such a long-and-far dispersion is often decades long.
But “something can survive on the spot,” Convey said of the moss that his research team found, “it can greatly increase the speed of invasion.” These mosses can “color” a lifeless land into a green color, enabling other organisms to live and grow.
Even so, the mosses of La Farge and Convey are just one of the representatives of creatures that can exist in the ice age.
Tatiana Vishnivetskaya learned about ancient bacteria enough to show this very normal. Vishnivetskaya, a bacteriologist who studied at Tenessee University, drilled deep into the permafrost in Siberia to map the network of protozoan that had flourished in the past.
She woke up millions of years old bacteria on a petri dish. “They look very much like bacteria you can find in today’s cold environment,” she said.
But last year, Vishnivetskaya’s team announced a “accidental discovery” – an organism with the brain and nervous system – that changed scientists’ understanding of enduring endurance.
Often, researchers often find unicellular organisms, the only form of life that is thought to be able to live for millennia in permafrost. They placed the frozen sample on a petri dish in room temperature and noticed something strange.
Wiggling between the bacteria and amoeba is a long worm, complete with head and anus – a nematode species.
“Of course we are very surprised and excited,” Vishnivetskaya said. At half a millimeter in length, these nematodes are the most complex Vishnivetskaya – or anyone else – who wakes up after a deep sleep.
She had predicted a worm of 41,0000 years old – by far the oldest “animal” ever discovered. He himself lived under the soil that Neanderthals lived and met modern humans in Vishnivetskaya’s laboratory.
Experts say these nematodes are capable of being suitable for thousands of years in permafrost.
“This worm can survive everything,” Gaetan Borgonie said, a nematode researcher at Extreme Life Isyensya in Gentbrugge, Belgium.
He said that nematodes are present everywhere on Earth’s diverse habitats. Borgonie found a large number of nematode populations two miles below the earth’s surface, in South African mines with low oxygen and high temperatures.
When environmental conditions are reduced, some nematode species may fall into a state of inactivity called a prolonged period, in which nourishment is delayed and a protective coating is developed to prevent them from conditions. hard.
Vishnivetskaya is not sure that these nematodes have passed the era of elongation, but she guessed that they had – in theory – survived indefinitely if frozen.
“They can survive as long as the cells are intact,” she said.
Borgonie agrees with this. When admitting the discovery of worms of the Pleistocene era was a big surprise, he said that “if they can survive 41,000 years, I don’t know their limits ever again”
He considers its endurance in a cosmic setting – “This is great for the solar system” – and thinks these survival victories can signal life on other planets.
In this Earth, many species are approaching the brink of extinction because of global warming. But near the Poles, some creatures are showing extraordinary tolerance.
In the ecosystem, many kinds of animals – from birds, butterflies, to wildebeest – survive by moving vast and dangerous distances to find a favorable habitat. Many recent discoveries show another mode of migration: through time.
After a lingering two-pole sleep of Earth, bacteria, mosses and nematodes are waking up in a new geological era. For these “genius survivors”, climate and weather are just enough for them to “sprout and sprout”.
Source : Genk