VIRUSES ON THE MARCH: IS THIS THE VIRAL CAMBRIAN?

If you want a reason to study microbiology, you’re breathing it, and now is the time to do it. Something extraordinary is happening in global microbiology: the advent of the viruses as a global force. Viral populations have exploded worldwide in less than a hundred years. They’ve gone from being obscure oddities in biological texts to being real global environmental forces. In terms of any comparison with any other form of life on Earth, there just aren’t any comparisons.

In the Cambrian era, life exploded on Earth. Vast populations of new organisms arose, colonizing the seas, and beginning the rise of the higher life forms of today. A biological upheaval like no other before or since, the Cambrian period still dwarfs other eras for sheer diversity and scale.

Now, the viruses are doing much the same thing, but in time frames nothing else could match. They’re classic ecological opportunists, another hallmark of successful life forms, able to adapt to environments and other organisms with staggering speed and appropriate strategies. They are definitely tough, and resilient to even the most appallingly toxic substances, both those used on them, and those from our industrial wonderland of cocktail poisons.

It’s taken a while to learn enough about viruses. They weren’t fashionable, not so long ago. Virology was barely even a science, well within living memory. There was a time when people didn’t even consider them a form of life. An odd description for things which are as active as viruses. For dead things, they seem rather busy.

If the Influenza Epidemic is taken as the introduction to modern viruses, it’s taken a long time, even by our standards, let alone theirs, to recognize the viral tsunami for what it is. Now, we’re talking knowledgably about pandemics, strains of viruses, and vectors of infection. Before, there were hardly any people who could hold a working conversation about viruses, let alone describe them in any detail.

Ecologically, the viruses are now becoming a top predator. They’re so new our immune systems don’t deal with them at all efficiently, which would indicate if nothing else that they weren’t the major threat they are now. They can smash up whole populations of other organisms, too, indicating that older species aren’t virus-proofed in their immune systems, either.

A basic principle of epidemiology is that nothing kills all of a population. In fact, severe losses are by far the exception. It’s not good technique for a pathogen to kill its host, as is well known. However, it’s also highly unusual for the infected organisms to have so few effective defences. The avian flu has been massacring bird populations. Other viruses are affecting plants much the same way, if not on as dramatic a scale.

(I hope any biologists reading this will excuse what will now be a determined attempt to avoid drawing any conclusions, because as far as I can see, there aren’t any conclusions in sight. It’s only recently that thorough study of viruses has been possible, and the sheer scale of the subject doesn’t lend itself to pronouncements of any kind.)

The conventional view of the virus is basically the headline variety, with some extra information, of whatever quality. It’s a dangerously uninformed view. Epidemics make headlines, but the fact of huge populations of extremely diverse types is pretty much ignored. The occasional news item obscures the much bigger issues.

There’s no point in scare mongering, anyway. The facts are impressive enough. According to UCLA at the end of the 20^th century, marine virus populations are 100,000 times what they were in the 1960s. That’s an awful lot of viruses.

Some of the notable facts about this information are that:

1. The marine environment contains a large part of the food chain, including human foods.

2. It’s a great place to find proteins, which is really all viruses need.

3. A marine epidemic could smash up more than just fish. It could trash entire oceans, and whole economies, even worse than our idiotic, mindless, over fishing and selfless creation of marine deserts.

4. Ocean life depends on marine microfauna. They’re no safer from viral attack than anything else.

See what I mean? The facts here are that there is a gigantic, and highly mutation-prone, population of viruses sitting right in the middle of one of the major environmental forces on the planet. “Scary” hardly covers it, even if you’re looking at nothing but threats. Soil viruses are about as ferocious, and as unpredictable.

To me, what’s a lot scarier is that this perspective hardly even begins to cover what the viruses are doing, as a class. “Diversity”, thy name is “virus”. There’s no part of a virus that can’t change, and no virus that can’t adapt. Their version of adaptability makes just about anything but human adaption look pretty tame. If you can just go grab some genes, replicate like crazy, and produce more potential mutants, how “adaptable” is that, or do we need another word? Is there such a thing as a non-viable virus? Even in theory? Are they the form of life which will never experience extinction? They can survive, undamaged, in space. Enough organic compounds have been found in comets and meteorites to believe they wouldn’t go hungry for long.

We obviously haven’t seen much more than the start of the show. They’re now coming up with some new tricks. A giant virus, called Mimivirus, which is bigger even than some bacteria, has been discovered, a few years ago. It was so big they thought it was a bacterium. It attacks amoebas, the original protoplasmic version of The Blob, and it has enough genes to do some self editing, make sure it replicates properly, and probably something to allow it to do home shopping, if Mimivirus’ litany of things viruses aren’t supposed to be able to do is followed. It’s “hairy” literally has a coat. It can survive extreme temperatures, and chemical attacks with things like alkali. It can also live outside its host, which sounds like a good strategy for something that specialized in amoebae. There are 450 genes in the thing that haven’t yet been analyzed, so nobody knows what they do. Viruses don’t seem to carry genetic dead weight, so they must do something.

Put another way, Mimivirus has blown all previous views of viruses out of the water. It is a significant discovery, because it’s not merely atypical, it’s strongly contradictory of the earlier oversimplifications. Much more of a revelation is that this massive virus, a hundred times bigger than HIV, is capable of doing so much for itself, of itself. Just shows what can happen when you shuffle your proteins the right way.

It also means viruses are capable of evolution. This is clearly not a simple bit of amino-acid knitting we’re looking at here. Eventually, someone will have a clearer idea of how this virus developed, but at this stage I think the really significant point is that viruses CAN develop into something as advanced as Mimivirus seems to be.

Also relevant is that nothing in Nature happens in isolation, by definition. All bets are now off about setting limits on the abilities of viruses to exploit their environs in ways that just haven’t occurred to us. Mimivirus is unusual, in that it’s a specialist in a particular prey. That may well have driven its development, but if so, there’s no reason to think that other viruses, particularly if forced to specialize, won’t do the same. At least one known law of biology, speciation, seems to be working, at least.

We can consider ourselves privileged, if not perhaps deliriously so, to be witness the start of a biological revolution like Earth hasn’t seen for 500 million years. We can think ourselves lucky we’re now able to at least try and understand it. In fairness, it was a bit more than early 20^th century science could properly investigate, but it was a very risky omission.

I loathe quoting people, even myself, but here’s one of mine: “Science is never currently wrong, just previously wrong.” Strategically, in terms of epidemiology, we were left well behind the eight ball. Virology was a seriously neglected science for a long time, almost pure esoterica. That was a mistake, and a bad one. It took HIV to make it an important part of biology. The viruses didn’t give us the option to be wrong for long. We could miss the signals, not interpret, not get the right perspective.

I can see a time when the viruses are the dominant environmental factor, or at least one of the major environmental forces. They can do that, we’ve seen it happen in local scenarios. They’re efficient, and efficiency pays off well in nature. I can also see a time when viruses are operating as industrial scale factories. That’s already on the cards, if not underway on a large scale. They’re so potentially efficient with proteins that it’s a bit hard to believe that capacity won’t be put to work some time. Designer proteins aren’t currently too easy to come by, and if you’ve got something that does that by its very nature…

I can also see some acquired immunity coming from our new biological playmates. Immunology has been lumbered with a particularly difficult problem, highly mutable pathogens being what they are. Even the flu vaccine is a pretty tricky call, deciding which strains are to be vaccinated against.

The only real option visible is to get the viruses on our side. We know they can destroy harmful bacteria. There’s reason to believe they can obstruct other viruses, too. If one strain is present, at least in some cases, the other strains don’t show. As vaccines, they do have signs of working, but there are so many viruses that could become a bit cumbersome without a generic fixer, like antibiotics used to be. We might even wind up with some sort of symbiosis, like our gut flora, except instead of a digestive agent, we get a portable protein analyzer and fixer.

Our role in this is somewhat familiar: “Adapt or die.” If the whole of world biology changes, we change. Like there’s ever been a choice. So grab the popcorn, folks; we’ve got a ringside seat at the biggest thing since the Cambrian. We’ve even been invited to participate. It’ll be something your genes will be able to tell your most distant descendants about, if we live through it.