The alien want to make some new virus (or editing the gene of existing virus) to increase human death rate, and they don't want human to know the virus has been edited. I have read some similar conspiracy theory, such as the SARS conspiracy. Some scientists said SARS is man-made while some said it is not man-made. How can scientists know whether the virus is man-made? What kind of changes in genetic structure is impossible to happen in the natural environment?

If you want to know more about the background:


Aliens from another universe came to the earth. Some functions in the human brain are useful to them. (The details are not related to the question.) People whose brain is to be used by the aliens will be dead. The aliens don't want people to know of their existence, so they don't want to use living people directly. Should the alien do so, then there would be many strange deaths occurring and human may discover the truth. So the aliens want to use "clinically dead" people. There is a 10 minute window of for the aliens to make use of the brain before brain damage occur. (The alien don't need to go to the scene and take out the brain from the human body.)

Quote from the second link:

Once someone has stopped breathing they have about 4-6 minutes until some brain damage begins to occur. At around 6-10 minutes some brain damage is likely. And, generally speaking, after 10 minutes, irreversible brain damage is almost certain. However, as mentioned earlier, there's no way to know with certainty so don't assume and stop rescue efforts.

To sum up, the aliens want more people to die, however, they want "sustainable development", the alien only want to increase the death rate instead of eliminating all humans.

  • 7
    $\begingroup$ I suggest you delete everything except the final paragraph. That's the only part that is relevant... it will keep answers more on target and be more useful for future searches if you delete the extraneous portion. If you really think it could affect the answers, maybe keep a sentence or two about the virus interaction with the brain. $\endgroup$
    – SRM
    Commented Feb 5, 2017 at 18:54
  • $\begingroup$ Perhaps you could ask at biology.stackexchange.com? Or, at least, post something in their meta, with a reference to this question? There are more experts there $\endgroup$
    – Mawg
    Commented Feb 6, 2017 at 8:16
  • $\begingroup$ I agree with SRM. None of that has anything to do with the question, which is disappointing when I get to it. $\endgroup$
    – JDługosz
    Commented Feb 6, 2017 at 11:05

4 Answers 4


There are a few ways one might try to identify an unnatural viruses. Human scientists would look for:

Remnants of genetic tools

Man-made recombinant viruses usually contain artificial elements, such as:

  • Selective markers, genes conferring resistance to weak lab antibiotics. These are used not by the virus itself, but while the virus is being put together in lab bacteria. However it's not rare to find natural bacteria that already have these, so their presence would not really be a giveaway.

  • Restriction enzyme recognition sites. These are usually six to eight base pairs. They occur often enough in natural viruses that detecting a few would not immediately suggest genetic manipulation by humans.

  • Multi-cloning sites. These are long clusters of recognition sites for several different restriction enzymes. One of these appearing in a virus would immediately give away that it is man-made.

All of these remnants could easily be masked by other tools (such as CRISPRs) that alter DNA without leaving a trace. So, aliens with genetic technology similar to our own could already hide the remains of the genetic tools used to make a virus.

Cat's tongue and Eye of Newt

DNA-sequencing. Results are in! Alright...huh? Potato starch-breaking enzyme? Deep-sea shrimp phosphatase? Tasmanian-Devil face-cancer cell protein? What are these doing in a "natural" virus? This kind of thing would be a clear giveaway of an artificial virus, man-made or otherwise. The man-made viruses we currently have today tend to contain elements from very distantly-related species. However, again, this is not strictly a giveaway. Natural viruses often species hop during their evolution, and incorporate (actually are made from) bits of diverse host DNA. So aliens could mimic the naturally-occuring diversity of these bits and pieces to get their virus under the radar.

Homology to known virus types

This is the big one. On finding any potentially "new" virus from a human population, the first thing researchers will do is compare its sequence with known families of virus. Nowadays this takes about two seconds. An alien-made and controlled super-virus is likely to be very different to any naturally occuring virus family. What will happen:

  • virologists are surprised,

  • publish in Nature,

  • become famous

Depending on how much advanced improvements/controls the aliens have built into their virus, its discovery could hit the field of virology from so far out in left field that the discoverers get accused of faking it, cheating etc. All the attention would only encourage us to look further into where this virus came from.

So, to play it very safe, aliens should restrict themselves to using an already-existing virus family such as SARS, and applying only a few point mutations.

Would that be enough to dramatically increase the human death rate? We don't know. But remember, in a farm or a forest somewhere, Mother Nature herself is putting those same mutations into SARS right now...


Nothing is impossible. Science will never definitively prove anything (nor does it have to). However, it can bring up some very solid evidence to support or refute the hypothesis that it is a man made virus.

There is a big difference between how man-made products work and how evolved products work. The man made product has a purpose, and it is tailored to that purpose. Any purposeful construction quickly reveals that it had a purpose.

Evolved products are typically spaghetti code, taking advantage of whatever could be found at the time. A gene for the eyeball is good for the liver? Great! Upregulate it and start churning out liver enzymes! However, this makes the product of such evolution notoriously difficult to predict. It's hard to look at a genome and say "this make a Monkey" or "this causes hemorrhagic fever." If a product is man-made, that unpredictability gets in the way of achieving the man-made purpose. We typically design structures which can be analyzed to prove that they work.

A great example is Stuxnet, the virus that hit the Iranian nuclear refinement centrifuges. After we analyzed the code for Stuxnet, it was very clear that it had exactly one target. A particular model of controller by a particular company was targeted, and the damage done was extremely targeted to the devices being controlled. Nobody who saw the disassembled code for Stuxnet could disagree on what its purpose was.

Let's contrast this with an evolved example: sickle cell anemia (SCA). SCA is a debilitating disease buried in our genetic code. You'd think we'd have evolved away from such a useless bit of code, but we haven't. It's not obvious why until you look at the entire ecosystem and find malaria. Malaria is a major killer in many parts of the world, and it turns out that if you have just one set of SCA genes, rather than the 2 required to get the disease, you gain resistance against malaria.

Both of these are examples of a very focused goal, but the results differ greatly. When you disassemble Stuxnet, it's very clear what it was intended to do. When you disassemble the genes for SCA, there's no obvious way to tell that it's a solution to malaria. The body simply found some genes that did the job, and ran with them. Without malaria, it's just a message without a context. With man-made things, the context is always visible.

You might be able to cover your tracks a bit by "evolving" a virus artificially in a computer. However, you would still likely do it fast enough that there would be telltale signs of order, signs of trying to accomplish an objective.

  • 9
    $\begingroup$ Then the next question becomes how well can the aliens obfuscate their code? $\endgroup$
    – Anketam
    Commented Feb 5, 2017 at 17:48
  • 2
    $\begingroup$ This answer is good but presumes that the method of creating the virus was not a genetic algorithm under enforced breeding conditions. In that case, telling artificial from real would become a good deal harder, perhaps impossible. We would still be suspicious if we didn't see the interim variations anywhere in the wild, but the obvious signature of a creator would be missing. $\endgroup$
    – SRM
    Commented Feb 5, 2017 at 18:59
  • 1
    $\begingroup$ @SRM That was the point of my last paragraph. You'll still see a lot of fingerprints. In particular, you would see the shape of the fitness function the viruses were tested against. You're right that it'd be harder though. Instead of looking for the fingerprint of their purpose, you might have to test it against a variety of alternate scenarios. Real life viruses are remarkably resilient, while GA's will only be resilient against what they tested. I always say that GA's just show you how bad your fitness function was in the first place. $\endgroup$
    – Cort Ammon
    Commented Feb 6, 2017 at 0:11
  • 1
    $\begingroup$ @NPSF3000 I couldn't do it from the weights alone, no. But if I could run a bunch of simulations using the neural network, I could make some very solid guesses because I think like a human. I can guess how humans might train their neural network. $\endgroup$
    – Cort Ammon
    Commented Feb 6, 2017 at 2:23
  • 1
    $\begingroup$ @NPSF3000 Point taken. Although I do so love a sci-fi show where the alien invaders are taken out by their own humanity. It's always fun to theorize about what might stay the same. $\endgroup$
    – Cort Ammon
    Commented Feb 6, 2017 at 5:02

The alien only want to increase the death rate instead of eliminating all humans.

They cannot do it with a disease. With any disease the death rate (the number of deaths for given number of births) will rise for a short time but will quickly stabilize at the same rate as with healthy population: every human can die only once. So to have more deaths they should increase births rather than spread disease.

  • $\begingroup$ How do you explain HIV? en.wikipedia.org/wiki/List_of_causes_of_death_by_rate $\endgroup$
    – fairytale
    Commented Feb 6, 2017 at 12:53
  • $\begingroup$ @fairytale Anixx's point is that the death rate will always be equal to the birth rate just with some time delay. If you kill many humans now, fewer humans will die later. The only way to increase the total number of humans dying is to increase the total number of humans born. $\endgroup$ Commented Feb 7, 2017 at 16:25

Assuming no attempt at obfuscation, an intelligently designed tool will not have aspects unrelated and unuseful for its function. Your new cordless drill will not have 3 power cords, two of which end in bristle brushes and cannot transmit power. It will not have pointless redundancy. It will be made economically. Also, if you are familiar with the tech, you will recognize aspects of the tech from earlier iterations of the same or similar objects; if not the components itself, the tech used to produce them. An engineered bacterium can be recognized because there is are standard toolkits used to insert or delete genes and these kits leave their signatures in the end product. Sort of like moldmarks on a plastic item or codes on a capacitor.

If I were these aliens I would not make a killer from the ground up, like Stuxnet. For one it is laborious and for two it will require cumbersome field trials before you can determine it will not work. I would modify some organism which was already a capable killer and augment it. This is more efficient and starting with something that has a track record means it is likely to work - at least no worse than the starting material.

If you are unfamiliar with the toolkit used by the aliens it would be trickier to determine something had been artificially augmented. If the augmentation was minor modification of existing structures / dna or addition of dna from a related organism it would be more difficult still.

Augmenting lethality is not trivial. Aliens might or might not have an understanding of what limits the lethality of a given lethal organism - for example, why did the 1918 flu not kill everyone? What limits the spread of cholera or ebola? These things are not obvious even to smart people who live on earth and try to figure them out.

An interesting spin on this would be the patience of the aliens. How fast do they need their brains? If they can take the long view a good strategy would be a farm approach: something which cut life expectancy at 45 but did not affect fertility or birth rate, and in fact increased both.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .