5 facts about viruses that might interest you

1. There are giant viruses

Yes, there are viruses in the world that called gigantic. You may have immediately imagined huge balls the size of a tennis ball floating in the oceans, but in fact, the size of even the most major of which Pithovirus sibericum — reaches 1.5 micrometers. That is, these viruses are larger than many bacteria.

Pithovirus sibericum was found in Siberian permafrost and is estimated to be 30,000 years old.

However, representatives of giant viruses discover not only in remote corners of the planet in ice, but also in the blood of quite healthy people. In general, a person is not their common target, but diseases like pneumonia they can call.

2. Viruses help us evolve

By the way, one more thing about the giants from the previous paragraph. Scientists have discovered proofthat the cell nuclei that we all have could to appear as a result of the symbiosis of ancient giant viruses and nuclear-free unicellular - archaea more than two billion years ago.

And this means that... we all evolved from viruses.

Have you heard the expression that humans and bananas have 60% of their genes in common? Well technically it is So. True, these genes work differently and encode different traits. WITH chimpanzee in humans, the genome is similar to 99%.

Versatility the genetic code of all living beings living today confirms that we have a common ancestor - for example, a giant DNA-containing virus, like the current mimiviruses. He once successfully settled in some kind of nuclear-free cell and remained there.

3. We are bisexual and smart thanks to viruses

Have you ever wondered how good it is that animals (including people) have two sexes? And they could reproduce by budding. Scientists believethat we owe this to the intervention of viruses.

The fact is that the proteins that our gamete cells use when fused during sexual reproduction are similar to those that apply by infecting their victims with certain viruses. For example, the dengue fever virus or Zika. And the mechanisms of their production are encoded by the same genes.

It is extremely likely that we received them when our distant microbial ancestors caught some kind of virus during mesoproterozoicabout one and a half billion years ago.

Hooked up from viruses opportunity to create proteins that exude cell membranes, primitive eukaryotes learned to perform not simple division, but fusion and exchange genes. And as a result, they began to multiply and evolve at an accelerated pace.

By the way, the functioning of neurons in the form in which we now observe them did not develop without the help of viruses. For example, a gene called Arc needed to transmit information from one neuron to another to all beings with a central nervous system.

And, apparently, we inherited it from viruses. And in the end, we owe them the ability of our brain to remember information, and the muscles to maintain motor functions.

4. And we have a placenta too because of them

Yes, it was thanks to viruses that mammals got the opportunity not to lay eggs, but to bear cubs in the uterus. Ancient endogenous retroviruses contributed development of the placenta in animals.

Some primitive ancestors of modern mammals picked up a virus that caused mutations in their genetic code. And foreign genes have taught their bodies to produce the proteins necessary for the formation of the placenta. The retrovirus has adapted to use this mechanism to infect not only mothers, but also their babies.

Over time, the infectious agent built in into the bodies of our ancestors, which became part of their genetic code, and without it, people would not be able to bear offspring.

5. Most viruses are very useful

Usually, when we hear “virus”, we think of diseases. After all, the word itself is translated from Latin as "poison". But in fact, dangerous pathogens among them are less than a fraction of a percent, and most, on the contrary, necessary for life on earth.

For example, bacteriophage viruses destroy pathogens, including inside people, and without them we would simply die from endless epidemics. In the future, the study of such microbial killers will allow create replacement for traditional antibiotics.

Other same viruses govern reproduction of plankton and algae in the oceans, and without them, the formation of oxygen on Earth would not be possible. We just couldn't breathe.

So most of the viruses are pretty good guys.