Since humans can enter space, in order to study the impact of the space environment on living things, every time everyone will bring some creatures from Earth, one of which has a life force that makes people scream shock, do you know which kind of creature it is? It is the tardigrade we are going to introduce today.
Tardigrades look a bit like caterpillars
So, what exactly is a tardigrade? What are its "unique skills"? What happened to the tardigrades that were sent into space? Can humans take advantage of it?
Whenever the viability of tardigrades refreshes people's three views again, everyone will think that if this creature has thinking, I am afraid that it will colonize all parts of the universe long ago, after all, they are too strong to be killed. With that said, does the tardigrade, known as the "strongest creature" on earth, really have the ability to live forever?
Tardigrades are very vigorous
Do tardigrades have the ability to live forever?
Many people should still be relatively unfamiliar with the creature of tardigrades, after all, they do not pay much attention to space experiments, and it is difficult to detect that there are still such strong creatures living around us. So, what exactly is a tardigrade? Why such a strange name?
The name of the tardigrade is actually obtained by scientists according to its appearance, do not see the bear word and think that it has anything to do with the bear, in fact, they are really eight rods can not hit. Judging by the rolling shape of the tardigrade and the way it walks slowly, the German biologist Johann Guez calls it a "little tardigrade." Later, according to its turtle speed, it was placed in the team of "slow walking animals".
Round and rolling tardigrades
The tardigrade generally lives in humid environments and is found all over the world, both above the Himalayas and in the deep sea. However, the "seeing" mentioned here is really not what we see with the naked eye, because the size of this guy is really too small, the largest is basically a few millimeters, and the small one is only a few tens of microns. Therefore, when scientists observe this creature, they generally use a microscope or a magnifying glass.
Tardigrades under the microscope
Speaking of which, many people may think that if it is so small, its body structure should be very simple! That would be a mistake, because although there are not many cells that make up tardigrades, their structure is actually quite complex. From the big picture, this guy not only has appendages and claws, but also has mouthparts that can puncture algal cells. And some of the tardigrades are hermaphrodites, some are hermaphrodites, so their reproductive methods become very diverse.
There are also hermaphrodites
However, scientists are most concerned about these, but put the tenacious vitality of tardigrades in the first place of research and observation. It should be known that in the experiment, whether it is deadly radiation or extreme pressure, or high temperature or waterless environment, tardigrades have a record of survival. From the current record, even at minus 278.8 ° C, it can still survive, and this "fearless" situation is very shocking.
Tardigrades can survive in extreme environments
So, does the tardigrade that doesn't seem to be afraid of anything really have the ability to live forever? In fact, the immortality mentioned here is a special reaction of tardigrades when encountering harsh environments, and scientists Spalanzani found that tardigrades will "dehydrate" when facing danger, and then enter a state similar to "hibernation". During this time period they no longer breathe or move, as if they are dead.
Tardigrades can survive in a variety of environments
When it comes to dehydration, many people who have watched "The Three-Body Problem" should feel very familiar, after all, the three-body people will also dehydrate when they encounter danger, and then wait for the environmental changes before encountering water resurrection, the dehydration of the tardigrade is actually the same as the trisolaran. If you look at it this way, don't tardigrades that have been dehydrated have the ability to live forever?
Not so, after all, it does nothing when it is dehydrated. Can it still be called "alive" in the absence of vital signs and activity? Therefore, this ability of tardigrades is at best to delay their own lifespan, rather than obtaining "immortality" like the gods in mythological stories.
Tardigrades are dehydrated when they are in danger
James Fleming of the Museum of Nature at the University of Oslo in Norway said:
Sometimes the media spread the idea that tardigrades can survive for hundreds of years. In fact, tardigrades have only a few weeks of life in their active state... The premise is that it spends most of its time in a "super dormant state" of hiding from the environment.
So, rather than saying that tardigrades have the so-called ability to live forever, it is better to say that it has the ability to "survive" and "come back from the dead". It is important to know that most living things on Earth lose a lot of water in their bodies, and their cells are damaged, so it is impossible to return to their original state of dehydration.
Can tardigrades "come back from the dead"?
Regardless of the length of life of the tardigrade, its outstanding performance in all aspects is enough to conquer us. After all, high temperature, low temperature, radiation, vacuum, high pressure, these factors that can easily kill humans are useless even if they are placed on its body, so scientists have always wanted to find the real reason why tardigrades have evolved to be so "excellent".
The real identity is the "DNA Thief"
We often say that there is no perfect creature in this world, and if it is very good in one aspect, it is bound to be flawed in other aspects. But tardigrades seem to break this argument, because it seems to be unresponsive when it adds up to a lot of bad factors.
Tardigrades have a life force that amazes humans
Over the years, scientists have tracked and studied this creature, and then found that its strong vitality is actually "stolen". Because their genes were not completely inherited from their ancestors, the results showed that nearly 17.5% of their genes came from outside. This means that tardigrades are able to evolve these powerful abilities because they have been stealing the "genes" of other organisms and perfecting themselves by learning from each other's strengths.
Of course, there is more than one organism that contributes genes. Because the data shows that its genes have DNA from plants, bacteria and even ancient fungi, it also shows that tardigrades are indeed very "studious" in the long evolutionary journey, after all, it has been learning everywhere, and then adding the strengths of others to its own genes.
Tardigrades are good at "learning from each other".
In some cases, foreign genes have replaced the genes of the tardigrades themselves, and the unsubstituted genes in tardigrades have incorporated single or multiple fragments of the genetic material of one or more bacteria while still maintaining their own function.
As for how tardigrades have successfully stolen other people's genes, scientists think it is difficult to give a conclusion. A more reliable guess is that after the tardigrade encounters a harsh environment in survival and enters a "dehydrated dormant state", its genome will also be damaged or broken.
Tardigrades have the potential to break their genes
Therefore, after they are resurrected in contact with water, their cell membranes will remain "open" and repair the damaged areas.
In this process, some external DNA can also enter its body, and in this process of suspended animation and resurrection, it can easily collect other DNA and then use it for its own use.
You know, there are more than 900 kinds of tardigrades in the world, and the DNA stolen after surviving in different environments is different. Therefore, experts can find surprising features in different tardigrades one after another, such as the researchers of the Indian Academy of Sciences who have discovered a new species of tardigrades and have another "unique ability".
There are more than 900 species of tardigrades
A super shield made of tardigrades
It is reported that this tardigrade can use fluorescent "shields" to resist ultraviolet radiation, because under the continuous illumination of the laboratory sterilization ultraviolet lamp, these guys have changed color, from reddish brown to blue. In this case, they carried the radiation, and most of them survived the radiation for 30 days.
The team reported in the journal Biology Letters that it may be that fluorescent pigments located under the skin of tardigrades convert ultraviolet light into harmless blue light. In contrast, less pigmented tardigrades die about 20 days after exposure to UV light.
Tardigrades can survive even in space environments
In fact, tardigrades are not only able to rely on this method to resist ultraviolet radiation. The damage inhibitory protein Dsup also helps it reduce the damage caused by X-ray exposure. And after irradiation, its cells can still maintain activity and proliferative capacity.
Tardigrades can be used to protect against space radiation
The radiation resistance and regeneration of tardigrades surprised scientists, because if the future technology develops to a certain extent, we may be able to use tardigrades to make special protective clothing and shields to resist "space radiation".
Some scientists even believe that if the tardigrade gene can be combined with humans, it can also help humans obtain this ability, but this idea is too bold, and most people say that it is unacceptable.