Biologists are still arguing about what viruses are, whether they are living beings or dead matter. Encyclopedic dictionaries frankly admit: at present, science does not understand the nature of these creatures, does not know how and where they came from.
Scientists still agree that viruses are a special form of matter. It seems that they can be considered alive because they contain organic molecules, that they have their own genome, and they can reproduce. However, they are able to live and reproduce only inside a foreign organism, a foreign cell. Outside of it, they are just dead inert crystals, heaps of molecules.
To date, about two thousand types of viruses have been discovered. Supposed. that this is only a very small part of them. Viruses constantly mutate, new varieties appear from somewhere. sometimes causing deadly diseases such as mad cow disease, bird flu, Ebola, AIDS and others.
These ruthless cell killers seem so alien to everything earthly that many researchers who study them quite seriously state that viruses came to Earth from deep space. Their actions are really similar to episodes from horror films about an attack by representatives of an extraterrestrial civilization. A monstrous dwarf bites into a gigantic, the unsuspecting cell, dissolves its shell and screws into it “the spring of its DNA. This -spring "sets its own program to the cell, thereby changing its entire work. The unhappy affected cell forgets about its primordial responsibilities and begins to stamp more and more viruses from the resulting matrix, bringing death to neighboring cells.
Representatives of one of the varieties of viruses - bacteriophages (eaters of bacteria) - even outwardly look like a space module created for landing on an alien planet in order to take soil samples. The bacteriophage releases a kind of "support pillars" with which it is firmly attached to the victim, and then plunges its drill into it.
Viruses do not need food. They do not consume or assimilate it. As scientists admit, in their structure, viruses are more like primitive mechanisms that pursue one single goal: to search for living cells and integrate into them. But by whom, when and why was this task set before them? Experts do not even dare to think about this issue.
Viruses originated in space
In 2008, Doctor of Geological and Mineralogical Sciences S. Zhmur proposed his own hypothesis of the origin of life on Earth. In his opinion, the main ancestor of all living things were not cells, and not even bacteria, but viruses that originated in the space around the sun about five billion years ago.
After the outbreak of a supernova, huge masses of stellar matter were thrown into space, from which a gas-dust cloud was subsequently formed, and from it later - the planets of the solar system. The high temperature of this substance contributed to the formation of cyanides in it - chemical elements that are the basis for the creation of the simplest hydrocarbons. The next stage consisted in the appearance of proteins-enzymes and proteins-peptides on the basis of hydrocarbons, which then led to the synthesis of nucleic acid molecules. And this, in turn, allowed the formation of RNA and DNA, which “created” a peptide shell for their protection from harmful external influences. This is how a structure arose that is nothing more than a familiar virus.
It turns out that five billion years ago the gas and dust cloud of the future solar system was not just dead matter, but a substance saturated with the simplest viruses (remember the traces of microorganisms in the lunar soil and meteorites four and a half billion years old!). Subsequently, the Earth and other planets were formed from it, in which the embryos of life in the form of viruses were already contained from the very beginning.
The further evolution of viruses on Earth was due to water, which penetrated into them through the peptide shell. Some types of viruses swelled, protoplasm formed, and their genetic apparatus became more complex. All this led to the division of and. ultimately - the emergence of a full-fledged bacterial cell, which laid the foundation for life on the planet.
S. Zhmur does not exclude the possibility of a more ancient origin of viruses. They were able to arise in the substance formed immediately after the Big Bang. This means that the age of these microscopic creatures is almost equal to the age of the universe. That is, it turns out that a single living substance is poured everywhere in space, capable of giving rise to life on any heavenly body suitable for it.
Some researchers go even further, believing that viruses are biorobots artificially created by someone, which came to Earth billions of years ago along with organic embryos. The purpose of the biorobot viruses was to serve these embryos. Russian scientist M. Daryanenko believes that biorobot viruses were called
ensure the necessary course of evolution, connecting in a certain sequence with the cells of living organisms and introducing the necessary DNA programs into them. But over the millions of years of their activity, something has malfunctioned, and viruses from servants of cells have turned into their killers. It is possible that the biorobot viruses decided: life on Earth did not go according to the scenario prescribed by the program. And the experiment must be curtailed by clearing the planet for new experiments.
Is the mimi virus the missing link in evolution?
The question of the origin of viruses, from the point of view of most scientists, is still not paramount. The main thing is to understand what viruses are, how to coexist with them, how to deal with them. We learned about viruses relatively recently - only 100 years ago, but we really learned to work with them only in the middle of the last century.
Not so long ago, biologists believed that they had finally found patterns in the structure of viruses and the mechanism of their action. But the epiphany came in 1992, when an amazing, unlike anything object was discovered in an amoeba caught in the water of an industrial tank in England. It is 40 times larger than known viruses in diameter, but it is not a bacterium. Biologists have recognized it as a virus, calling it mimi - because of its mimicry, or disguise as a bacterium.
Striking results were obtained by decoding his genome. 1260 genes have been found in the mimi virus, while in ordinary, traditional viruses there are no more than 100! Another oddity: both DNA and RNA are in mimi. In common viruses, either DNA or RNA. Both molecules do not occur together in viruses. Mimi is able to reproduce 150 types of proteins and even repair its damaged DNA, which is completely impossible for ordinary viruses. And yet mimi is a parasite. He lives and multiplies only at the expense of someone else's cell, into which he penetrates. Then what is it? Maybe some intermediate form between viruses and bacteria that can shed light on the mysteries of evolution?
Precellular life form
Man is about two million years old. The age of viruses, by all estimates, is estimated at billions of years. Moreover, they can exist in a "conserved" state for an infinitely long time. In fact, viruses are immortal. Deciphering of our genome showed that it is full of remnants of ancient viruses. They occupy almost 10% of the human genome. Why these remnants are present there is still unknown. Similar questions science began to be discussed only in the most recent years.
Now among scientists, the opinion is spreading more and more that viruses are relics of some precellular life forms. Over millions of years of evolution, they have adapted to a parasitic existence in foreign cells. It also turned out that not all viruses kill cells. In other words, they are not all mortally dangerous, as many people think, otherwise humanity, and indeed all life on Earth, could hardly exist.
“Human civilization has known virus-related diseases in its history that have claimed millions of lives,” says Robert Shoupe, director of the Yale Virus Laboratory. - Sometimes it seemed that humanity is on the verge of complete destruction. But every time everything worked out more or less well. The viruses were retreating. Is this a coincidence? Or has it been programmed from the very beginning, from the moment life appeared on Earth?"