human extinction by a virus

Is it possible for a mad scientist to create a virus so virile that it will kill all humans?
What are the limitations of biological warfare in this respect?

This has been probably been asked before so please direct me to the thread.

Have you ever played the flash game pandemic or its successor pandemic 2? If you make it too lethal too quickly, a few people will die painfully before quarantine measures are put in place and the virus will die out once it’s killed its hosts. If you make it innocuous enough to sneak into all the countries, it’s probably not going to kill everyone.

I don’t think there is any record of the extinction of any natural species attributable to a virus, so it seems unlikely that H. sapiens, with all its self-serving medical knowledge, would fall victim to one.

I would put it in the realm of “not technically impossible, but exceedingly unlikely”.

It has been suggested that the pattern of extinction in some marine microorganisms is due to viral infections.

One strategy would be to create a virus that can infect other animals but which is not lethal to them. Ebola remains in the environment between human outbreaks because it infects other mammals without killing them. However, it would be tough to create a virus that would infect animals that all humans would be in contact with.

That is an awesome game really. You really have to engineer that virus and it’s spread, including places that are hard to spread to. Then you have to engineer mutations. And the zombies needed to win. Fun game.

There’s also the matter that there are 7 billion of us, and even with a relatively recent population bottleneck, that means a fair bit of genetic diversity. It’s likely that some proportion of humanity would happen to be resistant to the virus, just by the luck of the genes.

So the OP will have to fall back on the old tried and true “Hold the world ransom for $1 million” using a “laser.”

There has also never been a natural species which can carry an infectious agent to the other side of the world in 24 hours.

I don’t think that the game pandemic is a particularly illustrative model for considering whether a real disease could do what the OP suggests. It’s a very simple little game with no real underpinnings in biology.

If the incubation period is long enough, then the disease can spread far and wide before it starts killing people. Think of HIV/AIDS. People often have and spread it for years before they start to get sick. Of course, it’s rather hard to get HIV. It’s not particularly communicable, so it takes a lot of time to move through populations, and we developed treatments in the long lead time from when people started dying in large enough numbers for the medical establishment to take notice it in the 80s. Imagine that HIV was transmitted through a cough or sharing food or contaminated water. It could easily travel around the world and

If it’s very hardy in the environment, then the speed at which it kills people might matter a lot less. Here, think of the various bacteria that form spores. Anthrax can survive in spore form for centuries. Imagine that it was not safe to go into an area where people had been sick for decades after without taking extreme precautions. This is much worse than an animal reservoir, because at least you can try to contain or kill animal populations, and you can put people in quarantine when they have animal contact.

Now, is the combination of all these traits biologically possible? I don’t know. I’m not sure if we have the requisite knowledge about biology to figure out.

Actually IIRC humans are less genetically diverse than most species.

Our wide distribution and understanding of the concept of quarantine is more likely to help than our substandard genetic diversity; it would be extremely hard for some disease to reach everyone everywhere, right down to the last isolated tribe in some jungle somewhere.

Koalas are listed as threatened in much of their habitat because of a number of factors, one being a retrovirus.

Cue best ever Doctor Who moment

Madagascar will always be safe.

Step 1: Acquire small pox from US or Russia via nefarious means.
Step 2: Cultivate a strain that is resistant to all current vaccines.
Step 3: Weaponize the germs, develop a vector for distribution (natural or man-made).
Step 4: Get on the phone with the World Council and demand “One MILLION dollars! Mbwa-ha-ha-ha!”.

Didn’t you watch the Doctor Who bit then ?

For all practical purposes, you can eliminate this step. There is no stockpile of smallpox vaccine.

(Jenny McCarthy has nothing to do wit this.)


Zip it!

In a sense, there’s still a huge stockpile of smallpox vaccine, stored in the T cells of close to a billion people. Anyone who’s had the vaccine would survive, even if the rest of us are screwed.