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Tardigrade

    
tardigrade, water bear arpithecus ramidus Tree of life natural selection, the peppered birch Fish of the Abyss Toumai skull fossil
This animal is immortal ... Ardi is older than
4 million years...
The border between
inanimate and living...
Natural selection,
the peppered birch...
Life in the abyss
is surprising...
Our ancestor,
old 7 million years...
     
automatic translation Automatic translation    

Water bears are immortal

   

Category: Biodiversity

astronoo    
The tardigrades or water bears or bear water are tiny animals, between 0.1 mm and 1.5 mm, and multicellular invertebrates.
The cub of water the tardigrade name means "slow walker" is named by Lazzaro Spallanzani in 1777. The tardigrades are eight small legs ending in claws.
Their characteristic is to live in different environments around the globe, from polar regions to the equator, preferring mossy areas, such as forests and tundra, as the lichen is their favorite food.
Ingemar Jönsson of the University of Kristiangard in collaboration with ESA, has launched the Tardis (tardigrades in space) to test the resistance of tardigrades.
You board a Soyuz rocket four species of tardigrades were exposed to conditions in space. In the words of the article published in Current Biology, ultraviolet radiation, 1000 times higher than on Earth, would have destroyed its chromosomes. But after ten days, the tardigrades for the most part survived.
We already knew tardigrades can withstand a huge temperature range of -270 ° C to +150 ° C, vacuum or pressure of a huge ocean hypothetical 60,000 meters or 600 mega Pascal (6 000 bar). Swedish researchers believe that tardigrades in space does not emerge unscathed from their trip because the UV damaged DNA. However, some animals have managed to "repair" to survive.
On land, they are also present in the sand, foam roofs wetlands, sediment saline or freshwater. Their life is not really known, however, tardigrades are able to stop their metabolism and become immortal (state cryptobiosis).
These qualities make it an amazing super champion resistance animal.
 

In the laboratory, scientists have managed to maintain eight years in a state of cryptobiosis and tardigrades have returned to life.
To enter cryptobiosis, tardigrades retract their eight legs and is almost completely dehydrated.
They lose more than 99% of their water, replacing it with a sugar they synthesize.
This kind of antifreeze protects its cells. During this period he protects himself in a small ball of wax called microscopic barrel that limits water loss.
When favorable conditions return, water covers the Pooh to life.
Some insects, frogs and crustaceans are as capable of entering into cryptobiosis tardigrade, but the tardigrade can hold this for thousands of years and wait for warmer conditions for life miraculously recovered. Tardigrades were found in an ice sheet 2,000 years and came back to life.
This form of resistance allows it to suspend time, but also to survive extreme temperatures.
But whence comes this exceptional resistance?
Nature does not create living over equipped, compared to their environment, for nothing. How natural selection has done to test these features aliens?
The tardigrade is so resistant to extreme cold, that one wonders why. Since these conditions are absent on the Earth.
This oversupply of tardigrade is it due to chance or origins outside our planet?
The tardigrade is still an exceptional animal that could teach us a lot about life in the universe. Therefore, the scientific community shows towards this gifted, interest infinity.

 

tardigrade, tardigrada, water bears

* The tardigrades, measuring between 0.1 mm and 1.5 mm, are equipped with eight short legs ending in claws. On land, they are everywhere some is the middle. tardigrades are able to stop their metabolism and become immortal (state cryptobiosis). To enter cryptobiosis, tardigrades retract their eight legs and is almost completely dehydrated. This form of resistance allows it to suspend time, but also to survive extreme conditions.

nota : The cryptobiosis refers to a state completely stopped the metabolism of an organism. It is truly a completely inactive state, the animal becomes almost indestructible and immortal.

 
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