Author notes

303 - The View

El Cid

on March 13, 2020

…And at last, we are reunited with Abby and Delilah, those incorrigible scamps from Chapter 1. What have they been up to? And where is Manu? We'll be getting to all that in a bit. Stay tooned!





I should point out, this is not in direct reference to the current coronavirus pandemic, which absolutely no one expects to wipe out the human race. That is not to say you shouldn't be taking it seriously. Even if the odds of you dying from it are relatively low, you can still transmit it to others, and survivors may suffer permanent lung damage. It's nothing to sneeze at. (see what I did there!)

But it does raise an interesting question: Can a virus wipe out all of humanity? Has any species every been driven to extinction by a disease? It's one of our primal fears. I think if you polled people on what's most likely to bring about human extinction, most would rank disease somewhere in their top five, probably behind climate change, nuclear war, and the Earth getting bitch slapped by an asteroid.

It has happened before. Maclear's rat, a large and once abundant species of rat native to Christmas Island in the Indian Ocean, went completely extinct after a protozoan disease was introduced to the island by a British expedition. Tasmanian devil populations are being pushed to the brink by a contagious cancer that causes them to erupt in grotesque tumors (that's just begging to be made into a sci fi story!).



One thing that a lot of disease-driven extinctions have in common is that they often occur in genetically insular populations, which makes island-based species particularly susceptible. Without genetic diversity, there's very little to keep an invasive virus or fungus or protozoan from just laying waste to an entire species. That's not really the case with humans. There's enough robustness and diversity in human immune systems that it's highly unlikely that any naturally occurring virus could kill off the majority, much less all of us.

Take malaria, for example. In terms of body count, no other infectious disease comes close to malaria. You've probably heard the oft-repeated claim that half of all humans who ever lived, died of malaria… well, it's not true, but the real number is at least over five percent, which is still impressive. But despite it being the billy bad-ass of the disease world, humans have evolved defenses against malaria: sickle-cell trait, which evolved independently in at least four distinct African populations, provides a natural defense against it. Many people have a natural resistance to HIV, as well.



There's also an argument to made from evolution. Viruses are like parasites in that they don't necessarily “want” to kill their host; they need a living host organism to reproduce and spread. If they do kill the host, it's incidental and ultimately a bad thing. And if a virus kills off the entire host population, then it's likely caused its own extinction as well; it's like a wildfire that's burned through all the flammable scrubland and has nowhere else to go. So, over hundreds of millions of years, such “superviruses” would likely disappear, leaving just the more manageable “usual suspects” we're all familiar with. So, pending some long-dormant abomination emerging from a melting ice cap somewhere, it's unlikely we'll encounter something so virulent that it wipes us all out.

Of course, that's not to say that a virus – even one as relatively nonlethal as the virus that causes COVID-19 – can't create a great deal of social instability, as anyone who's tried to buy toilet paper or water recently has learned the hard way.