Your Questions Answered, Part 1: Biomedical

Hey, everyone! A couple weeks ago, I put out a call for questions from writers about sci-fi genetics things. Genetics and biotechnology are becoming really popular in science fiction, going right along with the scientific revolution they’re currently undergoing, and as a genetics major, I really like to see these topics accurately portrayed in fiction. Thank you so much to Victoria Howell and H. Halverstadt for asking these questions!

Is it possible in the future that a compound could be invented to speed up healing of all tissues?

The short answer is: anything’s possible, right? Actually, tissue regeneration, which is kind of similar to this question, is becoming a big thing; I knew someone once who was applying to a tissue regeneration master’s program at Brown University. As this article explains, though, speed healing is a tradeoff for accuracy in rebuilding tissues (the article also has some other great thoughts about regeneration, more than I can tell you, if anyone’s interested).

How do you think people in the future would respond physiologically to bacterial and viral infections?

I would say essentially the same way they do today, and presumably the same way they’ve been responding for thousands of years. Evolution (or adaptation, if you prefer) is a really slow process. It’s very difficult to imagine that, even in a thousand years, humans will have evolved something radically different from the current immune system; think of the expression, “If it ain’t broke, don’t fix it.” (But if a really aggressive disease swept through and wiped out everyone who couldn’t cope with it . . . who knows?)

In a society where human genetic engineering is commonplace, how do you think sickness would be affected? What kind of diseases can’t be eradicated by genetic engineering or vaccines?

This is a difficult question. In theory, humans could master the incredibly complex immune system and ramp it up somehow by genetic engineering, but that’s a far-off possibility. I don’t think genetic engineering would impact infectious diseases so much as terminal illnesses, and certainly genetic diseases. (Sure, if someone had a genetic predisposition to an infectious disease, someone could use gene therapy to reduce their risk of that disease, but I’ve actually never heard of a case like that.)

As far as eradication, some kinds of diseases are easier to eradicate than others. Smallpox was a good candidate for eradication for a couple reasons: 1) it has no animal vector (i.e. doesn’t spend part of its life cycle in an animal or an insect somewhere, which makes diseases very difficult to control—think malaria), and 2) when you’ve had smallpox once, you don’t get it again. Anything that doesn’t fit these criteria (which is a lot of diseases!) is difficult to eradicate, although the gene drive is being tested against malaria and other mosquito-vector diseases (see this post). Any kind of parasite (think tapeworm) could probably be eradicated with good living conditions (you don’t hear about Americans getting parasitic worms, do you? But they’re all over third-world countries). So bottom line, it’s hard to say, but it really depends on the kind of disease, what resources are available, and how much time is available to develop those resources.

What are the possibilities of a pandemic happening?

So a “pandemic” is defined as a disease outbreak that becomes prevalent over an entire country or internationally. This actually has happened and will probably happen again; H1N1 (swine flu), Ebola, HIV, and (I believe) Zika all count as pandemics. What I think this question is actually getting at is the probability of a world-decimating pandemic, and that’s hard for me to say with my limited medical knowledge. My guess is that it could happen, and if it did, it would devastate third-world countries with few public health efforts first, and unless it was an extraordinarily fast-spreading pathogen, advanced countries like the US would have plenty of time to prepare vaccines and minimize cases.

Cyber limbs are becoming more common every day. What limitations might someone with cyber technology face?

This is really more a computer science thing, as far as I can tell, but I’ll do my best to give thoughts from the biology side—just take everything I say here with a grain of salt. J So my guess is that cyber limbs would require some kind of wiring into the brain, for starters, and that would require some really tough, non-rustable wires (they would have to be metal coated in nontoxic plastic or something). Also, the body often rejects foreign objects, like nonsimilar organ transplants, as being “nonself,” causing the immune system to go on full attack mode and eventually making the person very sick. I expect this would happen with cyber technology as well. (I’ve actually heard of research projects dealing with the difficulty of creating bioadhesives compatible with the body, for transplants and what have you.) So my guess is most of the problems would be during the implantation phase.

Do you see new disease mutations happening to replace any that are eradicated? What kind of diseases do you think they would be, and how do you think people in this future world would physiologically respond to them?

To the first part of the question, I say absolutely. Disease organisms, like all organisms, mutate all the time. To give some background information, the average error rate per DNA replication cycle (which is all the mutation rate is, really) is one error per 106-108 nucleotide base pairs. That’s one error per 1 million-100 million bases, which is pretty low, really, but when you consider how large the genome is, and how many copies of the genome are present in multicellular organisms, it’s staggering. Taking the 100 million number for the human body, 37.2 trillion cells in the body, and a genome of about 3 billion bases, that comes out to about 1.1 quadrillion mutations in the human body every cell cycle, which is staggering! The moral of the story is, mutations happen in every organism, all the time, so yes, new disease mutations could certainly happen, whether in bacteria, viruses, or fungi.

With regards to human disease response physiology, humans aren’t exactly my specialty, but I expect it would be much the same as today. Evolution is a really slow process, unless humans sped it up by somehow engineering themselves with better immune systems, which is theoretically possible, but I’ve heard the immune system is so complex that I doubt this would be feasible without a technological breakthrough similar to that of next-generation sequencing (which revolutionized genetics and actually created the whole new field of genomics).

How do you think aging would be affected by genetic engineering and advanced medicine?

This is an intriguing and highly relevant question. Aging is one of the great scientific mysteries of our time, and as you can imagine, there are many scientists out there who are devoted to conquering it. To give some background, there are several current hypotheses about how aging happens. First, and perhaps most prevalently, the telomere theory: telomeres are the ends of our chromosomes, which shorten with each successive DNA replication. There is an enzyme called telomerase which re-lengthens them, but eventually, as we age, our telomeres shorten further and further, and the theory is that this contributes to the decline of our cells as we age. (This hypothesis is supported by the fact that cancer cells’ and germ-line cells’ telomeres don’t shrink at all.) Another hypothesis is called “antagonistic pleiotropy,” the idea of mutations accumulating in body cells (see above question), eventually reaching a detrimental level. Of course, one’s environment also plays into aging; people who eat healthy and so forth “age better” than those who don’t.

With that very long background discussion, we can get to some of my educated guesses. Perhaps humans would be able to engineer some kind of hyperactive telomerase to prevent the degradation of telomeres, or an extra-corrective DNA polymerase that could go back and fix its mistakes at a higher rate than normal DNA pol. And it might eventually be considered a form of gene therapy to go back and “fix” a person’s aged genes and try to make them younger again (although it’s a long shot that this would work, in my opinion). Environmental factors, of course, can always be improved; good diets, for example, might become more prevalent in the future.


That’s it for me today!

What do you think? Does this apply to any of your writing? Have you thought about these questions before? Do you have any follow-up questions? (I might not be able to answer them all, but I’ll give it my best shot!) Tell me in the comments!