Posted on 12/05/2004 4:16:24 AM PST by PatrickHenry
A University of California, Irvine scientist says viruses are much, much more than nasty little microbes that infect us with the flu. If he is right, they have infected all of life - with evolution.
In an astonishing set of papers and a new book, UCI virologist Luis Villarreal contends viruses are largely responsible for shaping how we look, how we speak, even how we think.
In fact, he says, they are an overlooked evolutionary force, one that has been powerfully influencing the shape of living things since life began - actually, since a little before life began.
"I'm saying they are a creative force in the evolution of all life," he said in a recent interview.
Villarreal, 56, is accustomed to challenging traditional ideas and swimming outside the academic mainstream. His unorthodox ideas about teaching, such as favoring immersion, not lectures, earned him rebukes from some colleagues but a presidential award from Bill Clinton. [Yikes!!]
He has conducted research with some of the biggest names in genetic engineering and microbiology.
And he knows his view of viruses will be hard for many of his scientific colleagues - let alone the public - to accept.
"Most people are blown away when presented with this information," he said.
The first step in understanding his thinking is to throw out most of what we think we know about viruses.
Sure, there are plenty of bad ones. The flu, West Nile, smallpox, polio - these are the bulls in the china shop, as Villarreal sees it. They blunder into the human body and cause pain, damage and disease in their hosts.
But the viruses he is most intrigued by seem to have little or no detectable effects. And we carry a lot of them - most that have been with our species since its beginning.
He calls them "persisting viruses," and says they are, in essence, the engines of evolution.
"Any species will have these parasites that are going to mark that species for what it is," he says.
For evidence, Villarreal's theory does what many of science's "aha!" theories have done in the past: It knits together a variety of mysterious, unexplained and seemingly unrelated observations into one plausible framework.
Not only human genetic material, but that of all animals and plants down to the single-celled varieties, is littered with the remnants of crippled viruses of various types, he says.
It is part of what has long been called "junk DNA," because it does not appear to scientists to do anything. The DNA that serves as instruction kits to build our bodies comes in short segments that make up less than 3 percent of the DNA in our chromosomes. These segments code for the building blocks of cells and bodies, and they are separated by long segments of noncoding DNA.
In reality, Villarreal contends, much, if not all, of this noncoding DNA is really bits and pieces of ancient viruses. They have modified themselves so they can reside comfortably deep inside our cells while avoiding our immune systems.
But they are far from being junk. Viruses mutate far more rapidly than more complex organisms - as much as a million times faster than their hosts, including humans.
That means many viruses are little packages of new genes that can endow an organism with all kinds of new capabilities.
When these viruses settle quietly into the noncoding regions of our DNA, their disease-causing tendencies are suppressed. Eventually they can be harvested by the host for new genes - for example, by reproductive cells.
Big leaps in evolution - such as, for instance, a capacity for language and symbolic thinking among humans - could have happened all at once, with the incorporation into our chromosomes of fresh new genes left behind by old viruses.
This could explain some features of evolutionary history that have puzzled scientists over the past century.
Some important changes seemed to happen very quickly, including the leap to human language, as well as the evolution of mammals, flowering plants and cells that carry a nucleus.
What is puzzling is how evolution, which we normally think of as slow, can sometimes happen in what looks like a geologic eye-blink.
Since Charles Darwin's day, we have known when it comes to evolution, natural selection appears to be in the driver's seat.
Random variations pop up in all living things from one generation to the next - a taller child born here, a plant with shinier leaves born there. Most of these variations, or mutations, are harmful, some do nothing at all, and a few are beneficial.
In nature's cruel but efficient system, the creatures with the beneficial mutations survive to produce more offspring than their contemporaries. The useful mutations gradually spread through the population, generation by generation, until upright primates with little body hair replace the furry knucklewalkers of the past.
But where do these variations come from?
Although Darwin, the originator of modern evolutionary theory, was the first to suggest random mutations provide the raw material nature uses to make its selections, he could say little else; in his day, scientists knew nothing of genes and chromosomes.
Later scientists discovered genes and said the random mutations were occurring among these.
Villarreal thinks that is only part of the story. In "Viruses and the Evolution of Life," a book to be published by ASM Press next month, Villarreal says viral genes get tangled up in our DNA over millions and billions of years of evolutionary time.
Eventually, the genes they leave behind get recruited for new duties.
If Villarreal is right, it means much of the genetic raw material that selection uses to shape organisms, including us, comes directly from viruses that invaded the cells of long-forgotten ancestors.
"This doesn't counteract any of Darwin's thinking," he says. "It explains facts that have been missing."
The theory's apparent explanatory power is, of course, no vaccine against defeat. Many big ideas that seemed to explain a lot ended up in history's wastebasket, disproved by later discoveries.
Still, Edward K. Wagner, also a virologist at UCI, called Villarreal's book "seminal" and said so far his work has been well-received in the scientific community and will likely prompt useful debate.
"There will obviously be discussion and controversy over it," he said. "I think these are very exciting ideas. What Luis is attempting to do is show that viruses are a tremendous source of biological diversity and genetic diversity."
And Villarreal's ideas go all the way back to the beginning. Viruses probably have been around as long as life itself. So they have been influencing evolution since Day One.
In all probability, he says, viruses got their start before true life forms evolved, in the "prebiotic" stage postulated by scientists. That is when self-replicating molecules might have begun organizing, eventually to become clothed in protective cells and to earn the name "life."
The idea we are largely a creation of our parasites crystallized slowly for Villarreal, starting when he was a graduate student in the early 1970s. He was doing research at the University of California, San Diego on whether viruses might modify or even disable themselves during infection, altering the outcome of disease. And he began to see evidence of repeated gene sequences that came to be called junk DNA.
The idea these sequences were really bits and pieces of ancient viruses came later.
Villarreal now hopes to conduct further research on these viral bits - including learning more about the individual histories of viral colonization that seem to be unique to each species, including humans.
But he knows while he has had plenty of time to get used to these ideas, they might make a lot of other people uncomfortable.
"There's a very strong cultural, negative response to the concept of a parasite of any kind," he said. "The irony is that if this is such a crucial creative force, that we look at it so negatively. If you want to evolve, you have to be open to being parasitized."
This is actually really old news.
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Could viruses be tiny little "fingers of god" working out the evolutionary process over the period of time known allegorically as "the seventh day"?
If so, it might explain why, when we have a cold virus infecting our nose and respiration, and we sneeze in response to that virus, good people everywhere say "God Bless You".
:)
Vectors.
Just another reason to buy a Mac.
I have a wild-hair hypothesis which pretty much mirrors this scientist's opinion:Viruses were the original "building blocks" of life-which may be one of the reasons we are so vulnerable to them.
Yep, In a book by J.P.Donleavy in the '60s. "Meet My Maker, the Mad Molecule"
When these viruses settle quietly into the noncoding regions of our DNA, their disease-causing tendencies are suppressed. Eventually they can be harvested by the host for new genes - for example, by reproductive cells.
Intelligent design.
No. Viruses predate mans creation of god by many millions of years.
Villarreal believes in evolution because he's infected with a virus?
Furthermore, by the way, Freepers are to be encouraged to reproduce. Every Freeper should have at least three children. You owe it to the human race.
Conversely, the morons of the Left are encouraged to use birth control.
> This is actually really old news.
Yeah, more than a billion years old, I'd wager,
Thus the atheist speaketh.
Viruses predate mans creation of god by many millions of years.I am an agnostic who accepts the current iteration of the Theory of Evolution as a highly verified scientific explanation of the evidence we find in geology, paleontology, zoology, and molecular biology.
But I would never have the hubris to proclaim with anything like the certainty you seem to have that humanity's various concepts of god are "invention" rather than "revelation".
I happen to agree with you as a matter of personal belief, but I would never state my own personal belief as categorical fact, as you seem to be so willing to do.
And for the record, viruses predate humans not in millions of years but hundreds of millions of years, at least. Possibly billions of years.
Man didn't create God, but men have clearly invented the notion that men can understand the nature of God to the extent that any evidence contradicting one's personal interpretation of God is without merit.
Some people's level of pride is simply astonishing.
I'm not sure it's slow. The drift part (mutation) seems to increase (genetic) distance proportional to the square root of the time taken. However, the selection part converges extremely quickly. I formerly thought (and even posted) that selection converges proportional to the time but actuall it's exponential in time. My simulations were converging too fast so I had to develop a new meta-model to explain my model. (I never meta-model I didn't like, but I digress.) The mathematics of selection are rather like those of "particle filters" which converge quickly. The mathematics of mutation are like those of random walks. Evolution uses both random walks and filtering at the same time.
men have clearly invented the notion that men can understand the nature of God to the extent that any evidence contradicting one's personal interpretation of God is without meritCould you rephrase that please. I'm not getting your meaning.
Verrrrrry interesting. He just could be right, y'know....
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