Ancient virus recovered from permafrost has genes not found on Earth
An ancient virus of unprecedented size has been recovered from 30,000-year-old permafrost in Siberia and reactivated. Incredibly, sixty percent of its genes do not resemble anything currently found on Earth.
The virus, which is so large it can be seen under a microscope, dates back to a time when mammoths, Neanderthals, and early humans walked the Earth. And now it has been revived, bringing new fears that other potentially harmful pathogens could be released by the thawing tundra of Siberia.
The virus, which has been dubbed Pithovirus sibericum after the Greek ‘pithos, meaning a large amphora, is infectious to amoebas but does not appear harmful to human cells. It was found in a 100-foot-deep sample of permanently frozen soil taken from coastal tundra in Chukotka, near the East Siberian Sea, and the detailed findings have just been released in the journal Proceedings of the National Academy of Sciences.
Exploration of the Siberian permafrost is expected to increase as it is thought to contain thirty percent of the world’s oil reserves, gold deposits and other key minerals. There is therefore a danger that viruses which humans have never encountered before, and have no immunity to, could emerge from the ice. “The revival of viruses that are considered to have been eradicated, such as smallpox, whose replication process is similar to that of Pithovirus, is no longer limited to science fiction,” said Professor Jean-Michel Claverie, from the National Centre of Scientific Research, who revived the virus with Chantal Abergel, his fellow researcher and wife. “The risk that this scenario could happen in real life has to be viewed realistically.”
But perhaps the most ground-breaking aspect of the research is the fact that it doesn’t resemble any other virus known on Earth. Modern viruses are tiny and have only few genes. But Pithovirus sibericum contains an incredible 500 genes, placing it in a new category of viral giant, a family known as Megaviridae. “Sixty percent of its gene content doesn’t resemble anything on Earth,” Dr Abergel said.
In a radio interview broadcast on BBC Radio 4's Today programme, Professor Claverie explained that the recently discovered giant virus has been made out of different genetic material than that which is currently known, suggesting it is without any “common history”.
“When we find more and more of those giant viruses it seems to point to some kind of multiple origin of life other than only a single one because they are made of totally different genetic material in a way and so we really wonder where that is coming from. We don’t see any trace of common history”
The implications are huge – if life has “multiple origins” what are they? And where are they from?
Featured image: Depiction of a virus - this is not a true representation of the Pithovirus sibericum
Comments
Turugi, yes it would be interresting to know to which extent the "unknown" DNA is different. It could easily be called that if:
1: It is not corresponding to a known organism
2: It is not corresponding to a known class of organisms
3: it is not even corresponding to the most basic "code" used by known organisms
Being a virus, it would have to be able to use some organism to run its production of new viruses. In order to do this, it would have to use the same type of code as this organism, the machinery wouldn´t work otherwhise. So, if this virus proves to be so very different, there would probably have been equally very different organisms that it was infecting in those times.
As conditions on earth have changed very dramatically in the long perspective, it seems entirely plausible that there have been other, now extinct, classes of life on earth. As there are some resemblance (what 40% mensioned) to excisting organisms, it should not be entrely synthetic and not extraterrestrial, in my view .
I know they aren't considered lifeforms. But reading the updated definition of life you gave at the end of your comment seems to indicate you would include viruses as a form of life...right?
They could be a form of life, and I agree it is possible that they specialized down from intracellular bacteria. I was just pointing out how they also fit the description of very advanced nanotech.
However, given that the Megavirus discussed in this article contains DNA sixty percent of which is not shared by any known organism, what does that imply about the specialization hypothesis? This is not a rhetorical question, I am interested in what you think because I have no idea.
According to current definition, viruses are not life forms. The accepted current definition of what life and lifeforms is, lies on that it is showing methabolism or alternatively have latent/ potential methabolic capasities. Viruses ( DNA coded particles), retroviruses ( RNA coded particles) and prions ( protein coded particles) does not have methabolism on their own, they need to hijack some other cell to do this and to thereby also multiply. I would agree to the current view that they have evolved out of intracellular infectous bacteria, specializing down to a particle transporting the code and the "keys".
In my view, a more modern way of defining Life would be " Molecules that are catalysing, including any level of complexity, a reaction resulting in that same molecule" .
Panspermia? (I'm not saying it was aliens, but....)
Really, to me the entire concept of a virus is baffling. They are basically hugely complex molecules, unlike bacteria, which are single-cell life forms and thus immensely larger and more complex. Bacteria consume and reproduce.
Viruses don't consume or reproduce. They have chemical keys that allow them to penetrate cell walls and get at the nucleus, then they start futzing with the genes there, flipping switches and unplugging extension cords and stuff.
They infiltrate and reprogram.
They don't sound like life forms. They sound like science fiction. Nanotech.
And now here we have an ancient Megavirus, far more complex than any known modern ones, 60% of which is unlike anything known on earth.
So.....aliens.