Thread by @sebastiangood

I just had the flu & well, #coronavirus, so: a thread on viruses. They're AMAZING.

First? There’s a lot of ‘em. If you lined up all the 10^31 viruses on earth end to end, they’d stretch 100 million light years, enough to cross the Virgo supercluster of galaxies.

Since the 1980s we've known the ocean had viruses, but only recently did we discover just how widespread they are. A single drop of seawater contains 10 million of them. There are 10 times as many viruses as the mostly microorganisms they infect.
futurity.org/millions-of-ma…

You and I think of fish when we think of the ocean, but 90% of the biomass of the oceans is microorganisms like bacteria and plankton. Of this biomass, 20% is killed DAILY by viruses. Yes, every day 18% of what's alive in the oceans is killed. By viruses.
researchgate.net/publication/59…

It's believed all this daily bacterial carnage is actually important for the carbon cycle & making the ecosystem more stable. Indeed viruses are the biggest bank of genetic diversity on the planet. An amazing feat for things that aren't even alive.

the-scientist.com/features/an-oc…

It's suprising that something non-living is such an important player in our ecosystems. A virus is just a special armor of deliberately deceptive proteins around a chunk of DNA that to hijacks a real living cell to make more copies of the virus. Watch:

Since they're not alive. They can't move. Or even wiggle. So they have to be creative to get from host to host. The flu virus makes you sneeze only so that you spray your coworkers with trillions of copies. Nice work!
kdshives.com/2012/04/28/86/

Viruses by their nature are destructive: in most cases they make so many copies of themselves they destroy the cells they inhabit. The cells are worked to death. But sometimes viruses just hang out. Waiting. Undedectable until their later reactivation.
medicalnewstoday.com/articles/27889…

The viruses you've heard of -- ebola, influenza, polio, smallpox, HPV, rabies, HIV, coronaviruses -- are generally nasty, making you at least sick for a while, and sometimes worse, like giving your cancer or killing you.
livescience.com/56598-deadlies…

So I started wondering: there must be good viruses, too, right? Maybe some viruses are good for us because they kill bacteria which would otherwise make us sick. Or they are just useful for, like, reasons, because complex systems are complex. Answer? YES!
medicalnewstoday.com/articles/32716…

Once you've got a gun you can point at a very particular target, and jam it with either death or a genetic payload of your choice, you have a novel form of medicine: giving someone a virus to make them better.

cosmosmagazine.com/biology/few-go…

They're good and bad: while we wage worldwide war to accomplish the extinction of viruses like smallpox and polio, the FDA also now routinely approves things like spraying viruses on your prepared food to make them safer to eat. newscientist.com/article/dn9863…

That wraps up this wander through the world of viruses. Keep your nose clean, kid.