In the discussions of intelligent design, one hears a yearning for an old-fashioned creation story, in which some singular, inchoate entity stepped in to give rise to complex life-forms—humans in particular. Now the viruses appear to present a creation story of their own: a stirring, topsy-turvy, and decidedly unintelligent design wherein life arose more by reckless accident than original intent, through an accumulation of genetic accounting errors committed by hordes of mindless, microscopic replication machines. Our descent from apes is the least of it. With the discovery of Mimi, scientists are close to ascribing to viruses the last role that anyone would have conceived for them: that of life's prime mover.
Many theists are willing to admit that evolution is at least possible, but remain convinced that the formation of our very first ancestor was too improbable to have happened by chance. Indeed it seems impossible that something as complex as a cell could have formed by chance and it's unclear what the precursor to a cell could be. However, if we start from a sea of amino acids and try to figure out the simplest possible replicator which could have eventually evolved into... well, us, than we might come up with something that looks a lot like a virus -- basically a strand of genetic material wrapped in a protective protein shell.
According to this fascinating article, some scientists are starting to believe that viruses may in fact be our ancestors. Also, even if the first replicator wasn't something like a virus, viruses may have played a key role in the development of the first cell nucleus.
Now, with the recent discovery of a truly monstrous virus, scientists are again casting about for how best to characterize these spectral life-forms. The new virus, officially known as Mimivirus (because it mimics a bacterium), is a creature "so bizarre," as The London Telegraph described it, "and unlike anything else seen by scientists . . . that . . . it could qualify for a new domain in the tree of life." Indeed, Mimivirus is so much more genetically complex than all previously known viruses, not to mention a number of bacteria, that it seems to call for a dramatic redrawing of the tree of life.
"This thing shows that some viruses are organisms that have an ancestor that was much more complex than they are now," says Didier Raoult, one of the leaders of the research team at the Mediterranean University in Marseille, France, that identified the virus. "We have a lot of evidence with Mimivirus that the virus phylum is at least as old as the other branches of life and that viruses were involved very early on in the evolutionary emergence of life."
That represents a radical change in thinking about life's origins: Viruses, long thought to be biology's hitchhikers, turn out to have been biology's formative force.
This is striking news, especially at a moment when the basic facts of origins and evolution seem to have fallen under a shroud. In the discussions of intelligent design, one hears a yearning for an old-fashioned creation story, in which some singular, inchoate entity stepped in to give rise to complex life-forms—humans in particular. Now the viruses appear to present a creation story of their own: a stirring, topsy-turvy, and decidedly unintelligent design wherein life arose more by reckless accident than original intent, through an accumulation of genetic accounting errors committed by hordes of mindless, microscopic replication machines. Our descent from apes is the least of it. With the discovery of Mimi, scientists are close to ascribing to viruses the last role that anyone would have conceived for them: that of life's prime mover...
Now, with the recent discovery of a truly monstrous virus, scientists are again casting about for how best to characterize these spectral life-forms. The new virus, officially known as Mimivirus (because it mimics a bacterium), is a creature "so bizarre," as The London Telegraph described it, "and unlike anything else seen by scientists . . . that . . . it could qualify for a new domain in the tree of life." Indeed, Mimivirus is so much more genetically complex than all previously known viruses, not to mention a number of bacteria, that it seems to call for a dramatic redrawing of the tree of life.
"This thing shows that some viruses are organisms that have an ancestor that was much more complex than they are now," says Didier Raoult, one of the leaders of the research team at the Mediterranean University in Marseille, France, that identified the virus. "We have a lot of evidence with Mimivirus that the virus phylum is at least as old as the other branches of life and that viruses were involved very early on in the evolutionary emergence of life..."
Even as Darwinism has come under attack from the theology of the intelligent design movement, scientists have never been closer to divining life's origins. With DNA evidence as solid as that used to convict criminals, researchers can trace the shared genetic lineage of life's different branches back to the very base of the tree, some 4 billion years ago, when the interaction between primordial bacteria and viruses culminated in the "mother cell," the common ancestor of all life on Earth. Although the remoteness and complexity of those events makes them difficult to piece together, viruses like Mimi are emerging as the key players in the picture...
How the first nucleus came to be is a question that has intrigued scientists ever since Scottish botanist Robert Brown first detected a cell nucleus while peering at orchids under a microscope one day in 1824.
The discovery of Mimivirus lends weight to one of the more compelling theories discussed at Les Treilles. Back when the three domains of life were emerging, a large DNA virus very much like Mimi may have made its way inside a bacterium or an archaean and, rather than killing it, harmlessly persisted there. The eukaryotic cell nucleus and large, complex DNA viruses like Mimi share a compelling number of biological traits. They both replicate in the cell cytoplasm, and on doing so, each uses the same machinery within the cytoplasm to form a new membrane around itself. They both have certain enzymes for capping messenger RNA, and they both have linear chromosomes rather than the circular ones typically found in a bacterium.
"If this is true," Forterre has said of the viral-nucleus hypothesis, "then we are all basically descended from viruses..."
We have been looking for our designer in all the wrong places. It seems we owe our existence to viruses, the least of semiliving forms, and about the only thing they have in common with any sort of theological prime mover is their omnipresence and invisibility. Once again, viruses have altered the way that we view them and, by extension, ourselves. As it turns out, they are not the little breakaway shards of our biology—we are, of theirs.
(via digg)