There are probably around a trillion species on Earth, and most of them are microbial. Make no mistake, it’s their world – and we haven’t discovered 99.999 percent of them yet. So it should come as no surprise whatsoever that 1,445 new viruses have just been discovered.
Writing in the journal Nature, the Australian-Chinese team identified the new cornucopia in 220 different species of invertebrates, a group of organisms without a spinal column. Insects, spiders, starfish, octopuses, snails and crabs fall into this group.
It’s well known that viruses are omnipresent across the world. They appear in every environment and all known species of animal. An ancient virus forms an entire section of our very own genetic sequence.
This study reveals that despite this knowledge, the viral world or “virome” is more detailed and diverse than anyone had previously thought. In fact, this new databank of species reveals that viral evolution has also proceeded at a remarkable pace, with plenty of gene transfer between the viruses and their hosts.
Many of the new discoveries have remarkable abilities to change their genetic code, swapping bits out for others in order to quickly adapt to new hosts and environments.
“RNA viruses are likely to exist in every species of cellular life,” the team, led by the Chinese Center for Disease Control and Prevention in Beijing, write in their study.
They note that this research “both re-shapes our understanding of the patterns and processes of their evolution and highlights the limitations of our knowledge on what are likely to be the most abundant organisms on earth.”
These new species were found in terrestrial and aquatic invertebrates all living in China. Their genetic codes – their RNA, a chemical “cousin” to DNA – were decoded, and the team was so unprepared to find so many new species that the viral family tree had to be effectively redrawn. It’s possible that this is the most prolific discovery of viruses to date.
There’s plenty we still do not understand about viruses. For example, it’s not yet agreed whether viruses are alive or not, something that remains a fundamental question in the biological sciences.
They do many things that bacteria, fungi, animals and plants do, but they cannot reproduce without a host cell, and lack other physical characteristics that would conventionally indicate they were “living things”. However, they are classified by species as if they were alive, albeit somewhat clumsily.
In any case, living or not, they are everywhere and in everything, and the world of the living depends on them. This study has pulled back the veil on the viral world quite dramatically, and our understanding of our microbial masters has just taken a huge and important leap forwards.
[H/T: BBC News]