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The unbeatable salamander

  As early as a century and a half ago, humans discovered the extraordinaryness of the dumb salamander.
  They have poor eyesight, weak hearts, slow movements, and naive looks. The amazing thing is that their red blood cells are 300 times larger than those of humans. It is hard to imagine how they, dragging their sluggish and deformed weak bodies, coped with the cruel living environment and survived on the earth for 200 million years?
  It may be that nature is also in awe of their tenacious spirit of survival, so they never give up and support them all the way.
  This makes us have to rethink the law of life evolution-how to cultivate the “weak flesh” in order to avoid being “eaten by the strong”?
  They are sluggish and ugly, like frogs but not frogs, fish not fish. Because of its strange sound, the Chinese call one of the salamander species, the giant salamander, “Salamander”. Most salamanders live in moist environments due to the rapid loss of water from their bodies. More terrestrial populations can live farther from water sources but still live in moist moss-dominated environments. Populations that are more dependent on water prefer to live in environments with low temperatures and clean water.
  Of the 766 known salamander species, more than 39 are completely incapable of growing from aquatic larvae to terrestrial adults. With juvenile gills and weak limbs, they can only be trapped in water their entire lives. What is it that prevents their growth and development, and stops them on the road of evolution? Scientists have been exploring for nearly a century without fully figuring it out.
The magic of regeneration that makes all living things unmatched

  The salamander’s name comes from an ancient Persian word meaning “inner fire”. For more than 2,000 years, even the “incarnations” of wisdom, Aristotle and Leonardo da Vinci, believed that salamanders were fire-resistant and even fire-extinguishing animals. In the Talmud, it is written in black and white that salamanders have a combustion-supporting effect, and smearing the blood of salamanders on the skin will make the flames burn. Although this is not the case, the legend of salamanders possessing magical powers is not groundless.
  We know that the regenerative capacity of human organs is the worst in the animal kingdom, at best within the reach of our fingertips. Slightly deeper wounds on the skin leave permanent scars. But the salamander’s super-regenerative abilities are real.
  Removing a salamander’s tail, forelimbs, hind limbs, or any part of its body, the salamander does not develop stumps or scars, and its ability to regenerate is perfect and amazing. A granulation grows first where it is missing, which grows like a branch blown by the spring breeze, and a new limb composed of intact muscles, nerves, bones, etc., silently replaces the lost limb. Everything seems to be reasonable, and it comes naturally, without leaving any traces.
  The most common specimen used by scientists to study the regenerative abilities of salamanders is a strange, unflattering Mexican salamander known as the “Axolotl”. In addition to limbs, axolotls can regenerate jaws, retinas, ovaries, kidneys, hearts, undeveloped lungs, spinal cords, and brains. It heals itself of all kinds of wounds without scarring. The axolotl can also integrate the body parts of the same kind into its own body, just like its own organs, without the usual immune rejection.

axolotl
Extreme to Horror Experiment

  When it comes to research on salamanders, we have to mention David Wake, a famous salamander biologist at the University of California, Berkeley, and his student Stanley Sessions. They were the first to conduct anatomical experiments on salamanders. Only their teachers and students have made scientific explorations on the regeneration ability of salamander organs and have made remarkable achievements, especially Stanley Sessions who made the greatest contribution.
  The biggest feature of salamander hearts is their self-healing and regenerative abilities, and they seem to have an inexhaustible supply of stem cells throughout their lives. Their ventricles are like empty bags surrounded by a thin membrane of muscle. This appears to be the shape of a human heart at the end of life in people with heart failure, where there are fewer cardiomyocytes, the walls of the ventricles are stretched and become thinner, and the heart is less able to pump blood. This seemingly disabled heart not only has no effect on the quality of life of the salamanders, but helps them live longer and live longer. This is incredible!
  Stanley Sessions conducted an experiment in which 27 species of lungless salamanders severed their right hind legs and then calculated how quickly they regrowed. He also anesthetized several fire salamanders with the help of assistants, then peeled back their thin skulls and removed nearly a quarter of each salamander’s brain tissue. Regenerating a severed leg is easy for a salamander, but Stanley wanted to test the limits of a salamander’s ability to regenerate. Sure enough, on the 40th day after the brain tissue was removed, new brain tissue in the fire salamanders grew back.
  So what makes fire salamanders so powerful at organ regeneration? Can humans draw inspiration from it?
Inspirations from the magical salamander

  With the help of modern scientific methods, we have learned that the size of the genomes of most mammals, birds, reptiles, and fishes does not vary widely, generally containing 500 million to 6 billion base pairs, which are strung together in long chains. , constitute genes, and many genes constitute the genome of animals. But salamander genomes vary widely in size, ranging from as little as 10 billion base pairs to as many as 120 billion.
  The giant genomes of salamanders govern every aspect of their lives, and they have found an unusually slow and unique way to survive over billions of years of evolution. They struggle to survive with stunted bodies, simple brains and paper-bag-thin hearts. But it is by no means lingering and hanging by a thread, most of them can survive for hundreds of years.

Salamanders parading in water

  Scientists who study salamanders have been surprised by the strange phenomena that they have shown, and then gradually have some clues. As Stanley Sessions said, for monsters like salamanders, we should abandon habitual thinking, such as the “survival of the fittest” theory that we have always believed in. But salamanders are different. Too much clutter in their genomes slows down their development, stretches their cells, and distorts their bodies. Here the “fittest” is redefined, with a strong heart and complex brain becoming secondary organs. Relying only on the tongues like quick guns and the ability to regenerate body organs, they stayed in a corner, avoiding one disaster after another caused by countless fires, floods and asteroid impacts, watching the fur-covered, The proud and vigorous companions of feathers and scales have been erased by the clutches of time, and only the quiet and calm salamander is still producing its own offspring.
  Under the sponsorship of a powerful international consortium, scientists have finally completed the sequencing of the axolotl genome. The axolotl genome is 10 times longer than the human genome, making it the longest genome ever discovered. Scientists involved in the gene sequencing said that for those who hope to one day use regenerative technology for medicine, the axolotl may be the perfect manual, but the manual needs to be decoded accurately, which is no less than human. Huge project to go to the moon.
  It’s important to point out here that Stanley Sessions doesn’t have too much hope for the claim that researching salamanders might benefit humans. He believes that human ancestors may also have some kind of organ regeneration function at the earliest, but for the sake of a developed brain and coordinated limbs, those secondary functions had to be abandoned. Moreover, the genetics of animals are also the result of thousands of years of evolution.