Evolution and Disease

[Berzerker]

I didn't want to hijack the virus thread but 'survival of the fittest' was touched on and 2 schools of thought were discussed. 1) we should try to reduce its impact on individuals at just about any cost, and 2) let the virus run its course with less effort controlling it to balance other concerns, like employment - ie people die from lousy economic conditions too.

The virus will have no benefit for the human species if the elderly get sick and die because they're beyond their procreative years, but for people who can have children, wont their offspring be more 'fit' for surviving related diseases if their folks survived and/or adapted to the bugs being produced by mother nature?

A while back I read an article that said the European descendants of people who survived the Bubonic plague did better when they got the AIDS virus - apparently the 2 diseases are related. Yet look at what happened when indigenous new world populations met old world diseases.

They were decimated largely because their ancestors had avoided old world diseases. Who knows why, but old world populations didn't suffer the same fate. Yes, some new world diseases were transmitted back to the old world but with nowhere near the same effect. Maybe the genetic diversity of the old world and exposure to more disease helped them get by when both hemispheres came into contact.

Do vaccines create that generational protection? Did the Polio vaccine solve that problem for the descendants of people who were vaccinated? I cant remember getting a vaccination for Polio, but my parents probably did get it.

If you're vaccinated for chicken pox as a child, will you pass that protection along to your kids or do you have to actually survive the pox? And if you survive the pox and someone else doesn't, is that because the genetic codes inherited by both people made one 'fit' for survival and the other less so?

I'm wondering if modern science can replace evolution when it comes to surviving disease. Are we setting ourselves up for a collapse like what happened to the new world if we continually employ modern medicine to short circuit evolution? We're here because of the latter, not the former. We vaccinate people to provide them with protection, evolution does that too but in the long term.

Ideally everyone would have a mix of genes from as many people as possible, right? I've read the reason some people can survive low oxygen environments like the Tibetan plateau and Andes mountains is because when some of our ancestors left Africa they met up with Denisovans living along Asian mountain ranges.

If we could push a magic button and isolate eg the USA from all old world viruses for the next 10-20,000 years and then that isolation ended, wouldn't the USA get wiped out by the first pandemic originating from the old world?

 

[Estebonrober]

hyper-evolution by genetic engineering

 

[Zardnaar]

No idea. We'll survive it the problem is the modern healthcare.

Health insurance won't help if hospitals are overwhelmed. Triage will just put you in the corridor and good luck.

 

[Berzerker]

do they still administer polio shots to people in the '1st world'?

hyper-evolution by genetic engineering

I imagine thats not too far away with gene splicing etc

I'm not sure I'd like that future even if has appeal, people would just 'edit' out traits for their kids and people would lose a lot of the diversity that makes us different.

 

[Birdjaguar]

do they still administer polio shots to people in the '1st world'?

Yes, it is still given.

Polio vaccines are vaccines used to prevent poliomyelitis (polio).[2] Two types are used: an inactivated poliovirus given by injection (IPV) and a weakened poliovirus given by mouth (OPV).[2] The World Health Organization (WHO) recommends all children be fully vaccinated against polio.[2] The two vaccines have eliminated polio from most of the world,[3][4] and reduced the number of cases reported each year from an estimated 350,000 in 1988 to 33 in 2018.[5]

The inactivated polio vaccines are very safe.[2] Mild redness or pain may occur at the site of injection.[2] Oral polio vaccines cause about three cases of vaccine-associated paralytic poliomyelitis per million doses given.[2] This compares with 5,000 cases per million who are paralysed following a polio infection.[7] Both are generally safe to give during pregnancy and in those who have HIV/AIDS but are otherwise well.[2]

 

[Berzerker]

wow, down to 33 is impressive

maybe one day they'll figure out how to make a vaccination become part of a person's genetic code so they pass along the protection to their kids 'naturally'

 

[Zardnaar]

Apparently 3 people still use iron lungs in the USA due to polio.

 

[Timsup2nothin]

wow, down to 33 is impressive

maybe one day they'll figure out how to make a vaccination become part of a person's genetic code so they pass along the protection to their kids 'naturally'

That would require altering the DNA in a live person, and I don't see that happening. Too many potential unforeseeable consequences, like, "oh, hey, that same gene sequence also associates with sociopathy...heh heh...who knew?"

Evolution requires that whatever the genetic difference is it shows up as a factor in the chance to produce offspring. People who were really susceptible to the common diseases were less likely to live long enough to produce offspring than people who weren't, so after a bunch of generations everyone is descended from people who weren't. As soon as technology "levels the playing field" that process is stopped. If someone was particularly vulnerable to polio but got vaccinated they were no less likely to produce offspring than someone with strong 'natural immunity' who got vaccinated. So there's no greater chance that someone born today has ancestors a couple generations back with that natural immunity than there is that their ancestors a couple generations back didn't.

What is theoretically possible is to identify the DNA sequences that identify with "hardier against disease" and do one of two things.

1) Use societal/legal means to make it more likely for people with the trait to produce offspring than people without it are. This treads into "eugenics" territory and gets really dicey really fast.

2) Engineer eggs and or sperm to replace the "weaker" sequence, if present, with the sequence associated with the "hardier" trait. This treads into humans as GMO and gets really really dicey really really fast. Again we hit those unforeseeable consequences pretty much head on.

 

[The_J]

The virus will have no benefit for the human species if the elderly get sick and die because they're beyond their procreative years, but for people who can have children, wont their offspring be more 'fit' for surviving related diseases if their folks survived and/or adapted to the bugs being produced by mother nature?

It might have a very meta-effect. I can't find the source anymore, but basically there's the idea that grandparents help fitness of their population, because they take care of the kids, giving the parents more time for other necessary things. So this might still have an impact, but not a good one.

A while back I read an article that said the European descendants of people who survived the Bubonic plague did better when they got the AIDS virus - apparently the 2 diseases are related. Yet look at what happened when indigenous new world populations met old world diseases.

I would check the sources of this article very carefully. Because this seems like something which is nearly impossible to trace. How did they figure out if someone's grand-grand-...parents had gotten the pest or not? I'd not trust this.

If you're vaccinated for chicken pox as a child, will you pass that protection along to your kids or do you have to actually survive the pox? And if you survive the pox and someone else doesn't, is that because the genetic codes inherited by both people made one 'fit' for survival and the other less so?

maybe one day they'll figure out how to make a vaccination become part of a person's genetic code so they pass along the protection to their kids 'naturally'

Very short wrapup how vaccinations work (simplified, with ignoring special cases, etc):
Vaccinations work by giving you a big dose of the disease causing agent in an deactivated form (e.g. killed by heat).
Your body will recognize that something foreign has invaded the system, and will produce antibodies against it, which neutralize it. You will not get sick during this time, because the pathogen is dead already (things like fever can still develop, since this is part of the normal defense system).
This can only be transferred to a child short-term. The child has its own immune cells, which have not encountered the disease, therefore do not produce the right antibodies.
While the child is still in the womb, these antibodies will circulate through the blood connection into the child and will protect it. After birth, they will still stay in the blood for a while, but will then be eliminated. Some antibodies are also transferred via breast milk, so this gives a bit further protection
Ultimatively, the kid itself will need to get a working immune system. Transfer is not directly possible, since this would basically need transfer of half of the immune system (which includes bone marrow, lymph nodes, thymus, and cells circulating in the blood).

Integrating this information would therefore be complex. You can't integrate the information about the pathogen into the genome, you might kill yourself. The information about the antibodies itself is not integrated into the genome, because this happens more or less on the fly. Part of the system to produce the antibodies (the HLA system) is also one of the most highly variable systems in the human genome, and gets re-shuffled all the time to allow the production of more possible antibodies (so the immune system has a trial and error system, and will produce things just by chance, to see if they're useful). Integrating anything in there is futile, since it will not really survive in its form long, since it will be re-shuffled.

So this is pretty complex. Maybe there'll be solutions in the future, but not in the close future, as I would guess.

Ideally everyone would have a mix of genes from as many people as possible, right? I've read the reason some people can survive low oxygen environments like the Tibetan plateau and Andes mountains is because when some of our ancestors left Africa they met up with Denisovans living along Asian mountain ranges.

It has been shown ( https://www.nature.com/articles/srep32550 ) that our setup of HLA genes (the ones mentioned above) has an impact on our pheromones, and whom we find attractive. Basically we prefer mates, which have a different immune setup in contrast to our own genome. So we're unintentionally already trying to mix.

 

[Senethro]

No. Just no.

Evolution is too slow a method of improving life quality to be bothering with. Forget it.

 

[Timsup2nothin]

No. Just no.

Evolution is too slow a method of improving life quality to be bothering with. Forget it.

One has to wonder how we as a species developed such a widespread disposition towards taking short sighted views.

 

[Berzerker]

No. Just no.

Evolution is too slow a method of improving life quality to be bothering with. Forget it.

Bugs can kill millions within a few years and the survivor's descendants will repopulate the land. Vaccines bypass that mechanism making bugs even deadlier, or the population more vulnerable. Hopefully gene splicing and DNA editing will replace vaccines, but I dont know if modifications like that can be bred into future generations.

You can't integrate the information about the pathogen into the genome, you might kill yourself. The information about the antibodies itself is not integrated into the genome, because this happens more or less on the fly. Part of the system to produce the antibodies (the HLA system) is also one of the most highly variable systems in the human genome, and gets re-shuffled all the time to allow the production of more possible antibodies (so the immune system has a trial and error system, and will produce things just by chance, to see if they're useful). Integrating anything in there is futile, since it will not really survive in its form long, since it will be re-shuffled.

So this is pretty complex. Maybe there'll be solutions in the future, but not in the close future, as I would guess.

Thats too bad, I was hoping we'd be able to introduce protection into the genome and it would stick and be passed along to the kids much like how the survivors of influenza will produce kids more 'fit' to survives the disease.

It has been shown ( https://www.nature.com/articles/srep32550 ) that our setup of HLA genes (the ones mentioned above) has an impact on our pheromones, and whom we find attractive. Basically we prefer mates, which have a different immune setup in contrast to our own genome. So we're unintentionally already trying to mix.

Is that why people tend to have a natural revulsion of incest?

As soon as technology "levels the playing field" that process is stopped.

1) Use societal/legal means to make it more likely for people with the trait to produce offspring than people without it are. This treads into "eugenics" territory and gets really dicey really fast.

2) Engineer eggs and or sperm to replace the "weaker" sequence, if present, with the sequence associated with the "hardier" trait. This treads into humans as GMO and gets really really dicey really really fast. Again we hit those unforeseeable consequences pretty much head on.

I suspect thats the only way we'll ever get away from vaccinations. Otoh the way creation is designed we're supposed to die and bugs are just one of many ways to remove us from cluttering the place up. We'll definitely need to replace a future with limited (or no) need for vaccinations with other forms of population control or cause collapsing ecosystems.

 

[Timsup2nothin]

Is that why people tend to have a natural revulsion of incest?

That seems more deep rooted societal than natural.

 

[The_J]

Thats too bad, I was hoping we'd be able to introduce protection into the genome and it would stick and be passed along to the kids much like how the survivors of influenza will produce kids more 'fit' to survives the disease.

Maybe we'll be able at some point, just not in a way we think of right now.
Some people have better immune systems than others. I'm constantly sick. One of my friends hasn't been sick the last 10 years. I'm sure there's a genetic difference, which partially does cause this.
With enough data, we might at some point figure out the difference, and then we can maybe genetically engineer us like this.
Very unlikely at the moment, and not in any of ours lifetimes, but who knows?

Is that why people tend to have a natural revulsion of incest?

I think that's one of the main theories, yes.