~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- Tardigrades or Water Bears are less than a millimeter long
- Under duress they can go into a state of suspended animation, when they become almost indestructible
- In that state they can be frozen at 272.8°C (almost absolute zero)
- They can withstand temperatures as high as over plus 150°C
- They can endure extreme radiation of up to 570,000 rads (500 would kill a human)
- And in that state of suspended animation they can float in outer space for hundreds of years and come back to life when circumstances are favorable
- All tardigrades have four pairs of legs and a complicated mouth.
- They come in the variety of colours (transparent, white, red, orange, yellow, green, purple, black).
- Water bears also show a variety of reproductive strategies (including parthenogenesis and hermaphroditism).
- Some species lay richly ornamented eggs
- There are more than 1,100 species of tardigrades.
- The tardigrade is essentially one giant head
- Tardigrades evolution is one more mystery in these creatures
- Their many legs correspond to the head legs in their cousins, the arthropods (crustaceans, insects, spiders, scorpions).
- Early in their evolution mutations resulted in their managing well without body segments. So well that today they are regarded as one of the toughest lifeforms on this planet.
TARDIGRADES ARE JUST
ONE GIANT HEAD WITH LEGS
ONE GIANT HEAD WITH LEGS
By Elizabeth Preston,
Inkfish blog, Discovery Magazine
No one would argue that tardigrades got stiffed in the weirdness department. These teensy animals, also called water bears, look roly-poly under a microscope.
Less than a millimeter long, they can survive extremes of heat, cold, pressure, and radiation that are deadly to most other lifeforms.
Under duress, a tardigrade may curl itself into a dried-up ball called a tun, then stay in a state of suspended animation for years before returning to life.
Now, researchers poring over the animal’s genes have found another oddity. The tardigrade, they say, is essentially one giant head.
Their evolution. Frank Smith, who’s a postdoc in Bob Goldstein’s lab at the University of North Carolina, Chapel Hill, and their colleagues studied the evolution of tardigrades by looking at their genes.
Continue reading
