Could a virus be used to terraform planets?

Question

I came up with a society of insectoid aliens called Ebline, based on ants. Their class structure and stuff are very interesting, but their coolest tool is a virus called Cuulaziu. When they find a new planet, they release drones to scan the flora, fauna, and geography. If the planet is hospitable enough, and a few of the organisms (Grass, trees, larger mammals, fish, fruit plants) are fairly genetically similar to the ones on their homeworld, the Ebline have the drones release Cuulaziu on the environment. This virus attacks genetic structure, warping and swapping DNA to alter the creature on a very critical level. Organisms that are unable to adapt to the strange changes being made will die a horrible death, but those that are genetically similar will mutate only a little bit. This gruesome event can last a few months, but when it’s over, the large carrier ships brimming with low-status Ebline will descend. After they’ve cleaned up the majority of the bodies, the rest of the Ebline touch down, and a new colony joins the fray. Of course, this might not be biologically possible. Any thoughts or dissertations?

Answer 1

This virus attacks genetic structure, warping and swapping DNA to alter the creature on a very critical level. . . . but those that are genetically similar will mutate only a little bit.

Real viruses do not modify or mutate the organism. They just hijack the organism's cells to make more viruses. I think there are some parasites that modify the host if they can infect the larval stage though.

but those that are genetically similar

Real viruses are specially adapted to their host. It is unlikely your dog can catch the flu from you. It is inconceivable an Earth virus could infect an alien creature. Even if they magically have the same DNA structure.

Any thoughts or dissertations?

Yes. What is the point of these viruses? Why and how do the ant people want to mutate the animals?

It does not seem important that these microorganisms be viruses specifically. But that's all you really tell us. They are viruses and they do. . . something to the animals?

Answer 2

It wouldn't work unless the viruses are perfectly "programmed" for the target.

Viruses work by modifying the DNA of a host and/or just tricking the helper molecules into replicating the virus as if it was the DNA.

If the host has a a non DNA method of replicating or it has a DNA that is incompatible with the virus, the virus will likely die to no effect.

Even with compatible DNA, viruses are often host specific (or host group specific). It doesn't take much of a difference in DNA to make a virus not work. A banana shares a lot of DNA with a human but if you sneeze on a banana plant, the banana plant is not going to get sick.

Answer 3

Viruses, no. Bacteria... maybe.

A virus is a target specific, organic molecular structure made up a capsule (or envelope) containing genetic material. The genetic material is literally made from a piece of the host organism's genetic code, that when broken away, acts in a destructive and autonomous way, and the capsule is the carrier mechanism that allows it to infiltrate the host cell. If you don't already have a access to a host organism's DNA, you can not design a virus to attack it.

Your goal is gene therapy. That is where we modify viruses in a way that they keep the capsule and change out the genetic material so that instead of functioning like a virus, it adds, removes, or changes a host's genetic code in non-destructive and non-self replicating ways. Again, you can't design a gene therapy virus without first examining the genetics of the host organism because the capsule that allows you to hook up to an inject into a host is as specific to the host as the genetics are.

So, what you need is a system that can assess the genetics of a host, and build a gene therapy virus that can attack it.

Bacteria are much more complex than viruses. This complexity makes them able to adapt to attack a wider range of targets because they have metabolic systems. Being able to expend energy means they can build and change organic structures ad hoc, so they can adapt to handle organisms they've never encountered before, but bacteria are too big and complex to infiltrate another cell to reprogram its genetics the way a virus would.

That said, there is a kind of cell that comes close to your goal that could maybe be modified to achieve it. Your white blood cells identify threats and then create antibodies which are basically custom built, non-replicating, virus like structures very similar to what you need. This idea could be expanded on such that you could have genetically engineered cells that can probe a foreign organism, identify its weaknesses, and then start pumping out custom gene therapy viruses instead of anti-bodies.

There is no reason such an organism would naturally evolve, but through advanced genetics, it would at least be more plausible.

Answer 4

I was going to say that this is not terraforming, but rather a blitzkrieg at planetary level. However, a massive destruction of ecosystems at a global level is sure to change the surface of a planet. This may take a lot of time - centuries, millennia or even millions of years, but for a spacefaring species (specially if they don't have FTL), this is an doable time frame.

Do notice that this is assuming a lot of things:

1. That the lifeforms in the target planet are based in DNA;
2. That most lifeforms have similar cell receptors for the virus to attack;
3. That the virus is able to affect all lifeforms in a similar manner.

Different organisms have different resistances to mutation and gene editing - for example, elephants and whales are generally said to have more than a handful copies of a cancer-resisting gene for which humans only have one copy. It might be that whatever life you are trying to mess up might end up simply becoming too resistant to the virus for it to have a long standing effect, in the grand scheme of things.

This may also backfire if the virus mutates to be harmful to your alien species. Might not be the case if their biology is too different (i.e.: they are sentient machines) though.

If you are keen on destroying most life on a planet, let me suggest you a cheaper, safer alternative. Use a relativistic kill vehicle:

A relativistic kill vehicle (RKV) or relativistic bomb is a hypothetical weapon system sometimes found in science fiction. The details of such systems vary widely, but the key common feature is the use of a massive impactor traveling at a significant fraction of light speed to strike the target. Therefore the weapon would be an extreme example of the real-life concept of a kinetic bombardment.

This short video in YouTube has a description about a grain of sand hitting the Earth at 99% the speed of light. It is fairly anti-climatic, so for kicks he throws the Halley comet instead and... just check it out.

Answer 5

Viruses are difficult to use to genetically re-engineer organisms. They can insert genes into a genome (in nature by accident), but they can't delete them. You can sometimes do this by inserting yet more instructions to ignore certain genes... but that is difficult to do.

Furthermore, the very nature of the mechanism through which viruses spread is destructive to cells. When a cell ruptures, thousands of copies are released and infect yet more cells. You have to destroy some, or only a few cells ever receive the modifications... but not so many that the organism is crippled or killed. This has to malfunction 99.9% of the time, and the rest act as a normal virus. All without accidentally killing some critical cell in the organism.

If you can't change every cell in the organism, you can change their non-somatic (or germline) cells and wait for another generation to be born. This certainly limits the number of cell receptors the virus would have to successfully target.

But virtually none of this is intelligent. The virus, without anything else, can only express proteins, or perhaps shut down existing genes. If you want anything more, then the virus has to code for a new ribosome-analog to "boot itself up", and then have genes that the new ribosomes will act upon (including presumably some logic). But as hinky as everything else has been so far, this is a million times more likely to go disastrously wrong and end up turning into some awful gray-goo scenario.

And of course, even all of this is very harshly limited to biospheres that are already very closely related. Even if the other planet uses DNA/RNA, do they use the same base pairs? Do they use the same codons? Can the viruses even fit into the receptors well enough to do what they were meant to? An alien planet may well have very similar systems to another, and all of this could be completely incompatible.

I've even seen the idea floated that alien proteins will inevitably be monstrously poisonous. Don't get to eat alien food. Don't get to kiss the alien green chick. Even walking around on an alien planet and inhaling their equivalent of pollen would murder you. Science fiction always requires some suspension of disbelief, but this plot point of yours requires a little more than some.

Answer 6

Good idea!

Sort of similar to this scheme How to prevent humans from being killed by alien diseases?

except instead of releasing a bunch of earth germs and fungus to do proxy battle you send your custom virus. Softens everything up down there because some of those critters might have made your Ebline sick. War of the Worlds and all. Cant have that!

Stuff that might be bad for your aliens will have died the gruesome death. Probably most things fall in that category. The few things (if any) that have made it thru the Cuulaziu cull will be redolent with the letter u (redulent? Redulunt!) and good company for your alien beasts.

It would be nice if the Cuulaziu virus could induce infected creatures to produce tasty treats (which the Ebline call truuts) for your aliens, so their deaths would be meaningful as well as horrible. What if the survivors of infection still used their bodies to make truuts for the Ebline but just did not die? That could be cool for the story. Because these survivors might still be tough MFs despite tasty Ebline truuts sprouting from their bodies.

Answer 7

You could destroy any DNA-using creature with this, so long as the virus is able to get into the subject.

Viruses can do a number of things. While many "simply" inject their own DNA in an attempt to commandeer the cell and produce more of it others can use tricks to get into the cell whole and basically function as a hostile Mitochondria that produces more of itself. Ofcourse besides producing more of itself it could do other things, like prepare a sequence that cuts the DNA of the cell to shreds or even produce substances like Destroying Angel which dissolves DNA (and would naturally require the virus's offspring to exit before it produces enough).

The key problems are: the DNA of the virus needs to be able to commandeer the cells of the target. If its the wrong species this can be a problem. Other problems is that the virus needs to be able to identify the correct cells and not inject itself into whatever surface it encounters. Additionally it needs ways to counter the unbelievably complex immune system of every single species it encounters, each unique and often even unique to invididuals of the species.

That means that you cant have a general purpose virus, you need to have a way of sampling all the key species, adapt your virus and then release it.