Holy Shit, Mass Extinction!

Mass extinction is, you might (very correctly) assume, a pretty bad thing. I mean, every mass extinction so far has paved the way for a new form of dominant life on Earth, so there are some silver linings. We're here because of mass extinction.

But still, an event where over 50% of the species on Earth have been wiped out can only be called a catastrophe. This has happened on at least five occasions on the geologic time scale. The worst of them was the Permian-Triassic Event over 250 million years ago.

This chart is the visual equivalent of jargon, but the Event in question is the highest blue peak.

In that event, up to 96% of the species on Earth were completely eliminated. While there are several theories as to the cause of this disaster, it's nearly impossible to tell for certain what happened. Maybe a large meteor struck the planet or a supervolcano erupted and kicked up enough dust to choke out the majority of life. Maybe a massive, cross-species plague swept through every living thing. Maybe the atmosphere simply changed and most life couldn't catch up.

The point is, shit died. A lot. And that was just the worst Mass Extinction Event. There have been several others. The most famous was the one that finished off the dinosaurs.

It's not like they were even phoning it in by the end. T-Rex was one of the last surviving species

The criteria for a mass extinction is that roughly half the species on the planet must have been destroyed within a short period of time. A short period of time on a geologic scale, mind you, means "within a million years or so."

Or, "Significantly longer than the entirety of human history

So when I tell you that Earth has lost 50 percent of its wildlife in the past forty-five freaking years, you should know that this means serious business. We are absolutely in the middle of a mass extinction. Right now. And we are absolutely the cause. Whatever your feelings are about the environment, there is no way that this will end up being anything but terrible for humans.

Because "mass extinction" really is just as terrifying as it sounds.

Holy shit.

Holy Shit, Reston Virus!

Our story begins as many unhappy stories begin: in an animal testing facility in 1989. This particular facility is located in Reston, Virginia, which is within the Washington, D.C. metropolitan area. A group of Crab-eating Macaques decided to take their own way out and, rather than suffering at the hands of horrific drug testing...uh, suffered at the hands of a horrific hemorrhagic fever.

It was rough, and many monkeys died. Too many. It was starting to get suspicious. While locking down the source of the disease, a researcher from USAMRIID, who had been dispatched to investigate the infection, noticed a new filovirus in some of the samples he observed. Being somewhat knowledgeable in microscopic terrors, the shape of the new virus scared the ever-loving piss out of our friend the researcher. Because it looked like this:

That doesn't look too scary...

Which kind of looks like this:

Yeah, but it's just a couple of lines...

Which is fucking Ebola.

As of this writing, Ebola is kind of a big deal. There's an outbreak underway in parts of Africa that has many of the more paranoid among us donning their brown pants. Imagine how brown their pants would be if they saw the above under a microscope in a lab where almost 200 people had potentially been exposed to it.

The lab was locked down, and everyone who had been in contact with the Macaques was immediately tested for the new virus. These are people who had been out in the general public after handling infected monkeys. The general public of Washington, D.C. As it turns out, six of them were definitely infected.

I guess that's it, then. Pack it in, America. We had a good run.

By the time this was discovered, the monkeys were dying at a rate of about one or two per day. One third of the lab's population died by the end. Apply that to Washington D.C. and you've got yourself a recipe for disaster - albeit one that would rid us of a number of unpleasant politicians. But by a stroke of unimaginable luck, whatever mutations the virus had undergone between plain old Ebola and Reston Ebola rendered it almost completely harmless to humans. When this was determined, the quarantine was broken.

Before you feel too much better, know this: evolution happens over many, may generations, but viruses live out many generations in a short period of time. Reston virus has already evolved in the time between when it was discovered and today. It can now transmit from pigs to humans. All it would take is a small variation for it to suddenly become as deadly as any other strain of Ebola.

And as far as we know, there are people in America -- people even in our nation's capital -- who already carry it.

So try to show a little respect.

Holy shit.

Holy Shit, the Oxygen Catastrophe

Let's say your an obligate anaerobic organism, and it's roughly two and a half billion years ago. You're hanging out on Earth, and you've pretty much got the whole place on a string. The world is your oyster (except those don't exist yet, so the world is your...I don't know, other, smaller type of obligate anaerobe).

One day, a new guy shows up. Or several million new guys, because they're bacteria and they come in large groups. These new guys, the cyanobacteria, are pretty different. They go through this whole process of photosynthesis and end up producing oxygen, and it's kind of weird. You're not a fan. In fact, the stuff is toxic to you.

More like toxygen, amirite? Guys? Hehe. Classic.

Luckily for you, dissolved iron and organic matter ends up capturing most of the oxygen, so you continue on your merry way for another 200 million years or so. At that point, the oxygen sinks become fully saturated. That means oxygen starts becoming a part of the atmosphere. For you and all your friends, that's a bad thing. A very, very bad thing.

The "anaerobic" part of "obligate anaerobic" means "without air/oxygen." The "obligate" part means oxygen will straight murder you. Which is exactly what happened. The same event that started Earth's atmosphere down the path toward being breathable also caused one of the largest mass extinctions of all time. It was essentially an apocalypse. The only survivors were the culprits -- who passed on the trait of photosynthesis to future generations -- and a few varieties of anaerobic bacteria that could tolerate the new atmosphere.

Oxygen was basically the Cthluhu of the obligate anaerobic world.

To get an idea of just how big the Oxygen Catastrophe was (and yes, that is an official name for it), just imagine the same thing happening today. Instead of oxygen, imagine it's an element that humans can't breathe. One that might cause dangerous fluctuations in the living conditions on Earth for the majority of its species. Something like, I don't know, carbon dioxide.

Oh, wait...

Well this isn't totally comforting.

Holy shit.

Holy Wombat Shit!

I'm going to make this exceptionally brief, for brevity is the soul of not-feeling-like-taking-the-effort-to-write-out-a-whole-blog-post-right-this-secondness. This is a wombat.

Yes you are, you cute little marsupial!

Yes. He is the cutest little doofus you can imagine. Now, here's his poo:

The logical next step.

It's square. It is a square poo. Wombats poop squares.

Why? Because the distinct shape helps to mark their territory, like a building block.

And it helps them identify potential mates, like that video you found in your uncle's special box when your parents weren't looking.

So, to recap: Wombats are adorable, but they're into square scat porn.

Holy cubic Shit.

Holy Shit, Delta 32!

C-C Chemokine Receptor Type 5, or CCR5, is a protein in your white blood cells. We don't know its exact function, but we're pretty sure it interacts with T cells, and it may play a key role in inflammations that result from infection. All in all, it's a pretty standard white blood cell protein. That's what HIV counts on.

Some forms of HIV use CCR5 as their point of entry into your immune system. When that happens, shit gets bad. That's why most early drugs given to HIV positive people target CCR5. It's more or less the main point of entry for the AIDS virus.

It's like that drainage grate at Helm's Deep. Only, you know, AIDS.

Now let's take a quick two and a half thousand year trip to the past and take a look at Ancient Athens. In 430 BC, the second year of the Peloponnesian War, Athens was struck with a massive, horrific plague that wiped out a fourth of its population. It was at this point in human history when CCR5 started to change. Medicine back then consisted mainly of blood-letting, the type of thing that lands you in a psyche ward nowadays. Back then you paid people to do it to you.

As a result, natural selection weeded out a lot of people via disease. Many survived, of course. Some of them had a bizarre natural resistance, which we now call CCR5-Δ32, or Delta 32. It's a gene mutation. A tiny variation in your genetic makeup that essentially deletes a certain segment of the CCR5 protein. As smallpox and various other diseases spread across Europe, the Delta 32 mutation became more common in the survivors, conferring various immunities to a lucky minority.

Alas, this did not include immunity to ludicrous superstitious violence.

Today, Delta 32 is found in about 10-15% of European-descended humans. The segment of CCR5 that it deletes turns out to be a chief cause of all kinds of problems. That includes the aforementioned HIV. I suppose you can see what I'm getting at. If you are of European descent, there is as much as a 15% chance that you are, if not immune, then highly resistant to the AIDS virus.

That's evolution at work. Think of the untold thousands of people who had to die so that this mutation could become as prevalent as it is. Think of how many people would have to suffer today for it to become a common feature in human beings. This relatively new strength, like all the strengths we enjoy as a species, came at a massive cost over thousands of years.

Luckily, we've gotten pretty good at tinkering with evolution since then. Rather than opening our veins and hoping all the sick pours out with our blood, we use real science to develop real medicine that really works. And the discovery of the Delta 32 mutation is a boon for medicine. We don't know how, and we don't know for sure it'll work, but it's very possible that this natural resistance might hold the key to curing HIV, a disease that only twenty years ago was synonymous with a death sentence.

Holy shit.