Viruses appear to be not only found on Earth. The reason, a group of microbiologists provide insight into the possibility of the virus can be found in outer space.
In a recent review published online in the journal Astrobiology, three scientists from the United States (US) and Japan said, the virus can spread across interplanetary. The researchers wanted to convince astrobiologists to devote more time searching for these strange molecular machines.
Virions-virus forms outside the host-consist of genetic material encapsulated in the protein shell. Some viruses also have an outer lipid layer called an envolope. According to the author, one way to imagine virions as seeds or spores.
Viruses lack machines to reproduce themselves. So they have to infect the host cell and hijack the machinery. This led to a decades-long debate over whether viruses should technically be considered alive.
However for the review authors, the method of viral reproduction is sufficient. "Indeed, when one considers the whole viral replication cycle, it is close to the working definition of NASA's life: an independent chemical system capable of evolving Darwin," the review quoted iNews.id of Live Science, Friday (26/1/2018).
If scientists identify viruses in space-possibly on meteors-the authors write, very few people claim, the discovery is not evidence of life in outer space.
However, why are not there scientists roaming the surface of Mars, Titan lakes or Enceladus geysers for evidence of this small form of life? The answer, says study author Kenneth Stedman senior because the technology to do that is under development.
Currently, scientists are looking for chemical signatures they can use to identify viruses in fossil recordings. But if they can not find the virus in the really old rocks on Earth, they will not be able to do it in the really old rocks on Mars or Titan.
The virus is not metabolically active itself, resulting in few byproducts. Lipids in envelope are the leading candidates for virus biomarkers, as they can last for hundreds of millions of years.
However, scientists have not determined, these molecules are unique to viruses and do not exist in any cellular organisms. Currently, scientists can identify viruses by looking at their shell structure using an electron microscope.
Given the diversity of viruses on Earth, Stedman says, he doubts scientists will recognize the form of a foreign virus. On Earth, viruses form an important part of life.
For this one, viruses are everywhere. The oceans alone contain approximately 10 ^ 31 individual virions. That amount, 1 million times more than the estimated number of stars in the observable universe. In addition, the virus is an integral part of most nutrient cycles on planet Earth.
What's more, viruses and cells have essentially evolved since life appeared on this planet. Cells evolve to fight their attacker viruses to give rise to new forms and behaviors.
Viruses shepherd genes between unrelated cells in horizontal gene transfer. When this process has triggered a tremendous diversity of life on Earth, it is contaminating the water for researchers who track the evolution of the virus.
Scientists know, viruses use RNA and DNA in single and double-stranded forms, to code their genetic information. All cellular life is known to use double-stranded DNA, so scientists think the virus may be the remains of ancient life forms that precede the development of DNA.