Questions about biology from the movie Rise of the Planet of the Apes

August 19, 2011 9:47 AM

Questions about biology, genes, humans and apes, courtesy of the movie Rise of the Planet of the Apes. SPOILERS WITHIN.

In the movie, a genetic virus is created to help Alhemizer patients, which seems to work well in one human, with the caveat that it's not permanent, i.e. constant treatments are needed. Eventually the human body in one host develops anti virus to that virus, plunging the human back into Alzheimer's.

When this virus is applied to chimpanzees, it increases their intelligence. It also passes down that intelligence to its children.

In time, the virus is perfected so that it can be delivered in the air, i.e. the one smart chimp (Caesar)gets ahold of several containers with the gas that produces the smart virus, releases it in an animal refuge for apes, chimps, gorillas and orangutans, thus building a smart army of apes overnight.

Eventually it's discovered the virus is lethal in many humans, killing them off, while producing only positive side effects in other members of the Hominidae genus.

How plausible is all of this, considering that apes are genetically close to humans. Obviously there's huge Hollywood license, but how much? Specifically:

1. The initial man made virus was designed to cure Alhemizer's and was being tested on chimps. It increased the intelligence and memory of a particular chimpanzee (Bright Eyes, Caesar's mother), but her offspring was hugely more intelligent, clearly on the level of humans. Is that possible, the huge increase of the effect of the virus on offspring? Is that a one time effect or would it increase with every generation?

2. Turning the virus into a gaseous form, which produces almost instant results in changing the intelligence of the apes, possible? I'm assuming it's not as we currently understand biology.

3. Not sure if the movie mentioned specifics, but what would the smart virus be manipulating to produce an increase in intelligence on the apes? Would it be changing the genetic structure or specific parts/pathways in an non human ape's brain?

4. How realistic is it that the virus kills off most humans, while making non human apes smarter? Wouldn't the virus do the same to all members of the Homindae family, especially since it wasn't designed to only target specific sub classes of that genus?

5. Eventually, it's discovered that Caesar can talk. Apes lack certain physical elements that prohibit them from speaking as humans do, correct? Obviously they can learn some language, i.e. sign, but vocally producing words is beyond their physical ability as I understand it. To enable them to speak would require changes in their physiology, right?

posted by Brandon Blatcher to Science & Nature (8 answers total)

Best answer: Is that possible, the huge increase of the effect of the virus on offspring?

Maybe? The movie is never really clear about what it thinks this virus is doing. Is it attacking structures that cause Alzheimers or is it gene therapy, where the virus actually rewrites the host's entire genetic code? Both are being considered right now, and gene therapy is frequently put forward as the cure for genetic disorders of all sorts. But here's the thing: if it's really gene therapy, as such, repeat doses wouldn't be needed, and the presence of the virus would eventually become unnecessary. But while the human patient needs constant doses which eventually stop working, a single dose is permanent in the chimps. You figure it out.

Either way, whether changes caused by virus/gene therapy would affect the host's gametes is an open question. It's entirely possible that they wouldn't, and even if they did, what would be the effect of one gamete with the treatment fusing with a non-treated gamete to form an embryo? I think the correct answer is "Who the hell knows?" But it strikes me as unlikely.

Turning the virus into a gaseous form, which produces almost instant results in changing the intelligence of the apes, possible?

That's actually three questions. First, virii can mutate such that they can be airborne. That's actually a huge concern for things like H5N1, etc. Second, the time between exposure and onset of symptoms can be as little as two or three days for virii like the Ebola virus. But that is probably something of a lower limit. It's going to take even a really aggressive virus some time to propagate sufficiently to do real damage. The third is whether this virus can cause intelligence in apes. The answer there is "Almost certainly not."

what would the smart virus be manipulating to produce an increase in intelligence on the apes? Would it be changing the genetic structure or specific parts/pathways in an non human ape's brain?

I think this is where the science fiction part kicks in. Intelligence is a really slippery concept, and even now we're only roughly aware of why our brains seem to produce sentience while ape brains, which are damned similar, just don't.

How realistic is it that the virus kills off most humans, while making non human apes smarter?

Making the apes smarter? Not at all. But affecting humans but not apes? Entirely realistic. HIV seems to derive from SIV, simian immunodeficiency virus, which is usually asymptomatic in apes, and there are plenty of strains of influenza which are endemic in animals, which don't even seem to notice them, but very harmful to humans.

To enable them to speak would require changes in their physiology, right?

Yep. That one came right the hell outta nowhere.
posted by valkyryn at 10:21 AM on August 19, 2011

Note, I haven't seen the movie so I'm going based off of the original run on things.

But wouldn't it be plausible that any sort of genetic modification that happened in the movie would be able to start a process that mutates the apes vocal muscles and allows all the apes of the future to talk?

Even ignoring the scientific problems with that we'd still have to deal with apes either stopping the reproduction of non-talking apes or apes forcing the treatment on all apes.
posted by theichibun at 10:38 AM on August 19, 2011

Is that possible, the huge increase of the effect of the virus on offspring? Is that a one time effect or would it increase with every generation?

This seems plausible (for science-fiction levels of plausible!) to me. Retroviruses splice themselves into their host's DNA, and if they get into germ-line cells the effect can become hereditary. And if the virus does [handwave handwave] that makes an adult ape smarter, it seems plausible that an ape that had that advantage from conception could benefit even more. Eg, consider an adult human whose mental capability was stunted by severe malnutrition in childhood: they'll benefit from better nutrition as an adult, but a human who grew up eating properly will be smarter still. If there are continuing effects in further generations that could be from epigenetics or maybe from multiple copies of the virus getting spliced into the genome.

Giving the apes the ability to speak (both the musculature and whatever extra language capability human brains have) seems harder to justify. But hey, the whole premise of the movie is that the effect on apes is completely unexpected, so I'm willing to accept that.
posted by hattifattener at 10:47 AM on August 19, 2011

Look, if you can buy James Franco as a supergenius scientist, everything else pretty much just falls into place.

Here's my question- assuming the virus is rewriting the DNA, how quickly does that kind of thing happen IRL?
posted by mkultra at 11:42 AM on August 19, 2011

Response by poster: Here's my question- assuming the virus is rewriting the DNA, how quickly does that kind of thing happen IRL?

I think it depends on what you mean. Don't some viruses hijack the the DNA of individual cells, one at a time? So technically, your question would pertain to individual cells. But is it possible to rewrite the DNA of all cells in the human body? I think not, but don't no for sure. If so, how quickly could it be done? That would depend on the strength of the virus.
posted by Brandon Blatcher at 12:19 PM on August 19, 2011

From what I remember the movie calls it a gene therapy, but then says it works by producing/repairing neurons in the brain, without any other factors mentioned.
posted by Hargrimm at 12:23 PM on August 19, 2011

Not having seen the movie, all of the retrovirus stuff needs to be taken with a huge grain of salt.

In talking about these effects, biologists make the distinction between somatic cells and germline cells. Germline cells eventually become sperm and ovum, while modifications to somatic cells have little or no effect. It's possible for a latent retrovirus to pass on to offspring, and we've documented dozens of latent retroviruses embedded in human DNA. People working with gene therapy generally try to avoid viruses with germline interactions. The effects on successive generations probably wouldn't be additive.

Viruses can be transmitted via an aerosol form. But a virus needs a certain incubation time in order to cause symptoms. Transformations due to viral infections in mere minutes is very unrealistic.

The intelligence question is a more difficult one and I think the writers here are taking substantial liberties in assuming a) genes linked to Alzheimer's are linked to general intelligence (g-factor), b) g-factor is determined by single-gene inheritance, c) low level of environmental factors.

Most current models of intelligence suggest that there's no single genetic switch which separates smart from less smart, but the additive co-evolution of multiple genetic factors involving both brain and anatomical changes elsewhere. For example, an expanded repertoire of vocalizations demands an expanded temporal lobe, which is linked to vascular changes and development of the skull, which in turn changes prenatal and infant development, which in turn has given Homo sapiens one of the most traumatic childbirthing processes known among mammals.

Gene therapy for Alzheimer's is more likely to influence the regulation of the sequence that leads to the formation of plaques in the brain rather than cause massive changes in intelligence.

Repeated doses of gene therapy might be needed if you're working with a sterile retrovirus as a carrier. You use a virus that can get into cells, but can't create an infectious capsule on its own. In that case, you'll have to keep supplying retrovirus to replace the cells that die off or are killed by the immune system. As far as I know, this is what you want to do with gene therapy because infectious viruses trigger immune responses, flag the cell for destruction, and could potentially spread to other people.

It is quite common for a virus to have a relatively benign effect on one species and a radically different effect on a related species.

Here's my question- assuming the virus is rewriting the DNA, how quickly does that kind of thing happen IRL?

What exactly are you asking here? The chemical process can take minutes. Spread of a retrovirus throughout an organism requires a bit more time. Seroconversion of people infected with HIV generally takes 2-4 weeks, which is a useful benchmark for identifying when a virus has reached a stage when it's widespread enough to trigger a specific immune response.

All of this is aside from the point, as I don't think the uplifted apes of the franchise are meant to be remotely realistic, just case studies in ethical and moral gedankenexperiments.
posted by KirkJobSluder at 12:28 PM on August 19, 2011 [1 favorite]

I don't have much to add to the answers here, but if I were a screen-writer trying to improve the suspension of disbelief by adding some more mechanistic insight, I would start by making up a whole new pathway for intelligence: That increasing the function of particular neuronal cells (some hippocampal subpopulation, I guess) in the brain can compensate for diminished brain function, as seen in Alzheimer's*, and that this can be achieved using a specially engineered retrovirus**. The virus would target these cells and transform them into super-functional cells, but also have the effect of decrease their lifespan. Thus, the patient needs to make new cells (a la olfactory neurons, which turnover, I think) that in turn need to be re-transfected. Hence the need for multiple doses. In some people, the high viral dose would cause a "cytokine storm" triggered by the immune system, thereby killing them (quite horribly, btw). Very plausible, the cytokine storm bit.

In apes, however, the virus would have the effect of extending the lifespan of these super cells, and cause them to proliferate and continue to propagate the virus***. And although there would be an immune response, it would be better tolerated in apes (not too implausible).

For the germline effect, I would explain that the continual exposure of the fetus to the virus during development (since the apes are now making the virus) enabled even greater expansion of these super cells, and that infection of the fetus would only serve to further propagate their expansion/function following their birth. I could even add another immunological angle: Since the offspring would be immunologically tolerant to the virus (unlike their parents), the would be no neutralizing antibodies to temper the effect of the virus, allowing it to have a greater effect.

*This requires a cellular explanation of intelligence, which nobody believes and bypasses all the structural/anatomical considerations that are likely important. But it's also kinda hard to condemn as completely impossible, because so little is understood about what makes an organism intelligent and sentience.

**We are talking about one kick-ass virus here, with lots of hand-wavy enigmatic terms like "miRNA", "histone modification" "DNA methylation" and "cellular reprogramming". Or maybe not. The less explanation, the less chance of somebody calling "bullshit!"

***Never mind that gene therapists wouldn't make a virus that was capable of this. Maybe it could be one of those "genius make rookie mistake" kinda plots though.


I've got nothing for the talking ape bit, though.
posted by kisch mokusch at 5:05 AM on August 20, 2011