I am throwing down the gauntlet. James, you sir, have insulted my and my discipline’s honour for the last time. Time for a good ol’ fashion debate. Here and now, let the readers be the judge. Have at you, sirrah!
Viruses are better than bacteria. I really shouldn’t have to say this; it is almost self-evident. They’re more populous, more deadly, more diverse, more resistant, more elegant, more beautiful and more important than anything bacteria have to offer. But we’ll go through this point by point, just so you get it.
First, they’re everywhere. Every organism on the face of this planet is attacked by some sort of virus. Think about all the different types of the organisms you can see (a dog, an ant, a fly, a tree outside, that guy creepily watching you read this article…), then think of the organisms that live off those organisms (mites, bacteria, parasites, fungus…); for every species, there are 10 different viruses that will infect it. If there is life, viruses that will parasitise off it.
Hell, there’s even a virus that infects viruses. Mamavirus is a huge virus that was found in a cooling tower and infects a species of ameoba. It contains 1.1 megabases of genome, which is bigger than some bacteria. It was so big that scientists weren’t sure for a moment that they were viruses. Then they looked closer and found that these Mamaviruses could be infected by completely different tiny virus, called Sputnik (Russian for “companion”). Sputnik-infected Mamavirus even showed disease: the Mamavirus replication slowed down and of those produced, many were defective.
Viruses are even in you. I don’t just mean “in you” in the sense of they in your gut, all over your body and sometimes infect you. No, I mean viruses have implanted themselves in your genome. Some viruses (for example, HIV) insert themselves into your genome. These viruses are called retroviruses. As a result of the human genome project, scientists found that only 1.5% of the genome codes for proteins, but 5% of our genome is composed of retrovirus sequences.
Even more interestingly, humans have learnt to use some of these retrovirus sequences. When a virus gets produced by a cell and goes out into the blood to infect new cells, it is exposed to the immune system (antibodies, white blood cells, antiviral agents). Some retroviruses have adapted to that by evolving a protein called HERV-W that fuses neighbouring cells together. So, to infect new cells, the virus brings surrounding cells closer and never has to be exposed to the immune system outside. But along the way, the gene for HERV-W got hijacked by the host cells. Now it is being used by humans to fuse its own cells together and form the placental-uterine interface during pregnancy.
Virus integration also occurs in all other species; viruses are an integral part of the very genome of these all organisms. So to completely eradicate the world of viruses, you would not only have to dredge the oceans, vaccuum up all the soils, but also completely wipe out any life on earth: basically, you would have to launch the Earth into the sun.
And wherever they are, there’s huge numbers of them. Take a standard 600mL bottle full of seawater from your local beach: you are now in possession of about 1011 viruses. That is the same number of stars in our galaxy. There are so many (up to 10 000 000 000 000 000 000 000 000 000 000 viruses in our oceans alone) that scientists have shown that viruses play a huge role in the carbon and nitrogen cycles. The theory is that when things in the sea die, the carcass sinks to the seabed where they’re eaten up by bacteria that can just go off and float away. If this was the end of it all, nothing could else could live because all the bacteria would contain all the nitrogen that was available. But instead, viruses infect sea-borne bacteria, make them explode and freeing the nitrogen so that other organisms can use it. The production of so many viruses in the sea also requires 27-270 Megatonnes of carbon. This means that viruses can act as carbon sinks and may have a significant effect on carbon emissions and global warming.
Virus evolution occurs incredibly quickly. The 5% difference in the genomic sequence between humans and chimps took 8 million years to develop. To produce the same 5% change, Poliovirus takes 5 days, about period of infection to excretion of virus. With this amount of change and the amount of virus being produced, it’s no wonder that viruses have evolved resistance to most antivirals that we use.
Thus, James and fair readers, I submit to you that viruses are superior to bacteria in every way. Viruses are everywhere, infect everything, swarm the earth in huge numbers and can adapt to almost anything. Rebut, if you dare.
‘Virophage’ suggests viruses are alive – Pearson H. Nature 2008 Aug 7;454(7205):677. http://www.nature.com/nature/journal/v454/n7205/full/454677a.html
Role of HERV-W Syncytin-1 in Placentation and Maintenance of Human Pregnancy – Noorali S, Rotar IC, Lewis C, Pestaner JP, Pace DG, Sison A, Bagasra O. Appl Immunohistochem Mol Morphol. 2009 Jul;17(4):319-28. http://www.ncbi.nlm.nih.gov/pubmed/19407656
Virioplankton: viruses in aquatic ecosystems. – Wommack KE, Colwell RR. Microbiol Mol Biol Rev. 2000 Mar;64(1):69-114. http://www.ncbi.nlm.nih.gov/pubmed/10704475