Expanding on this, CGP Grey had this amazing video (https://www.youtube.com/watch?v=JEYh5WACqEk) of why European diseases in the Americas were so bad on the people that were already here when the two worlds met but you hardly heard of Europeans getting any super contagious illness from the people living in the Americas. Meaning European genomes had some adaptations (as well as antibodies?) from dense and unsanitary living, as well as animal farming in European prior to contact whereas that type of living setup was rarer in the Americas.
Apparently native populations had a different immunogenic profile and that made them more susceptible to European diseases such as smallpox, and this was amplified by the lack of any immunity acquired by childhood exposures:
Charles C. Mann has a whole chapter on the epidemics that ravaged the Americas after the European arrival, in "1491: New Revelations of the Americas Before Colombus (2005)", and discusses this and other theories.
It's been discussed in many places on the internet before, but CGP Grey has a lot of profound misunderstandings around the Columbian Exchange and the new world as a whole. Some of it is that he's not an expert, some of it is that he chose particularly bad sources (e.g. the zoonotic hypothesis he cribbed almost directly from one of Diamond's older papers), and some of it is that there's a lot of misinformation about this particular topic on the internet.
The reality is that dense urban settlements (many without good hygiene), domestic animals (e.g. parrots), unsanitary conditions, and widespread trade/social networks all existed, subject to the usual caveats of time and place. We even have strong evidence of highly contagious diseases like Kirsten Bos' paper on zoonotic Tuberculosis in ancient Peru.
There are still many open questions regarding why the Columbian Exchange happened the way it did. Academics are still trying to work out the truth through centuries of mistaken narratives about what went down, including the now-suspect idea that there was ever a single continent-wide epidemic wave. We can reject some ideas (like innate genetic susceptibility) on the basis of scanty evidence, but most of them are hard to definitively reject and few people have the knowledge base to write books challenging the dunning-kruger type academics that are comfortable talking about continent-wide phenomena with simple narratives.
Covid made the social dynamics of epidemics a particularly interesting research topic to grad students, so maybe there'll be more consensus about big questions in a few years.
>It's been discussed in many places on the internet before, but CGP Grey has a lot of profound misunderstandings around
It is not just CGP Grey; other popular channels also share tons of misunderstandings and stuff related to tech or science. I believe YouTube also favours popular channels because of the high likes and comments. They dominate both Google and YouTube searches. I started noticing this around topics like Firewalls, RPis, Linux, Coastal Erosion, Global Warming, open source etc. The reason why top YouTubers are popular is because of their presentation style. It would be best if you did your research using multiple sources. Ask a question to university professors on Twitter (or email them), and they will happily guide you to the right resources. At least, that is how I do it and it worked better for me. YMMV.
Yeah I love some of these pop historical/sociological youtubers - until they venture into one of the tiny domains I know a little about, and I listen to their misunderstandings.
Then of course I think about how likely their knowledge of other topics - on which I "trusted" them due to my own ignorance - is similarly surface level.
The best presentation is the most suspect, particularly if the presenter has little focus and follows on to trending topics (you start to notice a topic does the rounds in several information entertainment venues and presenters in a short time).
Popular science presentations whether it be books, podcasters, or videos are quite low signal to noise.
To properly install Arch Linux (The way I want it setup) on my machine without any hitches, I need to use like.. 7 different videos, because they each leave something out that the other included.
Yes, yes, I know I should/could just use the Arch wiki. I really should just go do a deep dive into it someday. But my method works, so why fix it?
I've been in this field a long time, and I cannot think of a single topic which would be better served by video, than reading text. Video takes more time, has more cruft, such as blah blah I made this video because, and I discovered this because...), and video poorly presents for work involving typing.
SysAdmin work, or coding work, is not a visual art. Building a house, or assembling mechanical items are suited to visual work, or pictures, due to their nature.
But videos? How do you copy/paste code snippets from a youtube video? Or go through a list of 7 files to edit and look at?
Are you watching these videos, then making notes? Text instructions are the notes!
Sadly, I will agree that these days, there are endless generated blogs, articles, which are just gibberish or utterly useless. But the Arch wiki seems quite helpful in most respects.
Well, you may or may not like reading this, but here goes...
> I've been in this field a long time, and I cannot think of a single topic which would be better served by video, than reading text. Video takes more time, has more cruft, such as blah blah I made this video because, and I discovered this because...), and video poorly presents for work involving typing.
Ironically, the opposite is why I resorted to the videos. The text was often wrong, or useless due to being for some outdated version that doesn't apply anymore for some reason. A good example of this is text code snippets that use hypens when Arch expects an underscore. Which brings me to this...
> But videos? How do you copy/paste code snippets from a youtube video? Or go through a list of 7 files to edit and look at?
I type it out. I don't copy and paste unless I trust the code I am looking at. And I only trust things as far as I can throw them... Or know them.
So yeah, I write it all out, myself. And so I remember it better that way for the future.
> Are you watching these videos, then making notes? Text instructions are the notes!
More like I write it out in terminal to see if it works and does what I want, then (and I only recently started doing this part) I write down that code for my own use in a notebook for later. Which yes, I still type out. Why?
Because copy and paste is useful, but also lazy. IMHO.
And quite frankly, I think this is part and parcel as to why things are becoming gibberish and utterly useless. The code being shared is either wrong, mistyped, or just missing things entirely.
Arch wiki as I said before, I really should just deep dive into; but it was written by (IMHO) blowhard elites who only wanted people who already knew BASH intricately before installing Arch.
On some level, I don't blame them. I agree with the idea of barriers of entry to some certain things. But that thing is a whole new level of bullshit. Bullshit that I was able to get past and beyond, by just following a few videos where each person added in what the other left out.
I tell ya. The locales file was a pain in the ass for a while until I found the RIGHT way to do it. (Which I forgot again, but that video is still up, so I can thankfully refer to it)
Long story short, each tutorial text/video basically has a person changing it, when really... if you live in Canada or USA, you probably don't need to touch it much or at all. Same goes with the timezones, etc. Only small things need to be done to them. But some of these tutorials just give ya the work around until you bork your installation and have to start over again, wondering what went wrong.
So, with all due respect; I do not agree that following the text is the best method. Videos at least show you that the system works for them, even if they left something out. Which means you just need to find what they left out.
And I'm great at doing that sort of thing.
In the meantime, when I do my next install of Arch, I'll be writing down every little thing this time in my new little notepad, so I have a proper script to follow for any device I come across which has all AMD parts. Then I'll do the same with my laptop that has Nvidia in it... which means dealing with that bloody F'ing gpu switch stuff between integrated and dedicated graphics.
Then I won't need to refer to much else than the Arch Wiki for the few things where it matters. Or some random blog where the information is actually legitimate.
Like the BTRFS blog I came across that helped fix the suddenly filling SSD issue I ran into the first time I decided to leave EXT4 in the past where it belongs. (so many borked file systems because of a power outage because of that tripe.)
And I realize this may all seem wrong to you, but remember... It works on my machine. So that's all that matters.
Once I have this finally mastered as much as I care to master it; I'm moving on to Gentoo.
You're correct that some cities existed in the Americas on par or larger than most European cities (ie Teotihuacan). I don't know why people don't just chalk it up to an accident of viral/biological disease evolution. You could imagine an alternate timeline where the native Americans had survived similarly horrific incidents as the Justinian and Black Plagues, as well as Smallpox, but then Colombian exchange brought back the diseases to Europe.
Maybe it was just an unfortunate coin flip of history.
Maybe the racial diversity in the Eurasian-African land mass contributed to the disease diversity and acuity?
If you just want my idle speculation, my personal guess is that diseases did exist in the Americas, but 1) we lack the ability to see them in the record and 2) the dynamics of how those diseases originated/spread is significantly different between afroeurasia and the new world.
One of the problems with archaeology is that things have to be archeologically visible in order for us to realize they exist. Diseases usually don't leave skeletal evidence and many American cultures were big on cremation besides. It's only under very unique circumstances with certain diseases (e.g. the mummies with tuberculosis mentioned previously) that we can clearly see the evidence to say "hey, these people died in a disease outbreak". In Eurasia we rely heavily on literary sources to supplement this issue, but we have few American sources and they're mostly focused on other things.
The nature of continents is also substantially different. The Americas were hugely affected by late quaternary extinctions that destroyed the mammalian diversity, a main factor in zoonotic transmission [1]. The places where that diversity exists post-LGM like the Amazon basin are very remote and their pre-Columbian history is not well studied, let alone the history of disease there. We have little understanding of how they integrated into broader American trade networks either.
Eurasia's biodiversity is spread across large areas of the continent, which happen to be crossed by continental trade routes. If plague had originated in Venezuela instead of from rodents in central Asia, we might not even know about historical outbreaks and simply label it a new disease when modern farmers in the highlands caught it.
According to Wikipedia, Teotihuacan had an estimated population of 125,000 or more, "making it at least the sixth-largest city in the world during its epoch at its zenith", which is thought to be no later than 550 CE. Rome is estimated to have had 1,000,000 inhabitants around 0 CE. Certainly the Europeans had much greater population and density. How could they not be carrying around more virulent parasites?
Rome's population collapsed dramatically after the fall of the empire, by the medieval period, Rome's population was 20,000. Even London didn't exceed 100,000 until the 17th century and most European towns were small villages with a few hundred to a few thousand at most.
By my reading of history, the Americas were relatively better off than Europe for much of the dark and middle ages, in average health, height and even lifespan. They were probably at least as populous as Europe if not moreso.
Teotihuacan was one of the largest cities in the world for much of the last 2000 years. Modern day Mexico City (25 mi from where Teotihuacan was) has 9 million to this day.
There are also massive ruins of cities in the Amazon for which we know very little about from this era. The biodiversity is also incredible in the Amazon, so there could feasibly be many zoonotic diseases in those jungles. I'm partly playing devil's advocate here, I do think the racial diversity and intercontinental exchange in the old world contributed to it.
I am aware that Rome’s population decreased. My reasoning is that a population that was larger and denser in the past is carrying around more parasites. Rome is just one example. By 1492, Europe had many large cities and lots of travel between them, enormously more population and travel than the Americas. They had a more fertile environment for parasites.
The idea I'm talking about here is an older one that virgin soil epidemics devastated American populations because they were innately susceptible to them, often as a result of genetic homogeneity or something. That's not supported by decades of research into those kinds of questions.
This article is talking about selective pressure as a result of epidemics, which is absolutely a thing.
No, it's best to think of them as unrelated. On one hand, you have an argument that "virgin soil" epidemics in the columbian exchange were deadly because Native Americans had no genetic diversity (not true) and thus effectively no differential susceptibility. That's a complex narrative causally linking many different processes and observations over centuries.
On the other, you have a statement that disease can cause selective pressure.
The only relationship is that they're both about genetics and disease.
"Native Americans had no genetic diversity (not true)"
That feels a bit like a strawman. Few people would claim that Native Americans had no genetic diversity.
But the claim that they had less genetic diversity than Old World populations is plausible. After all, there was a massive population bottleneck/founder effort in their relatively recent history. The groups of people who walked across the Beringia and settled the Americas had to be small-ish, with their total size not exceeding several tens of thousands. Siberia is, until today, very sparsely populated.
Compared to the Old World, the New World population squeezed through a population bottleneck of perhaps 0,1-0,5 per cent of the total human population of that time. It then started diversifying again, but genetic drift is a longish process.
I've seen it (incorrectly) described before that native Americans were practically clones from a genetic perspective, so it's a relatively mild strawman.
Founder effects did reduce genetic diversity of native Americans and it takes a long time to rebuild that. We actually use this to track historical migrations. It's also worth pointing out that a very similar process affected everyone outside Africa. That's why the sharpest dropoff in genetic diversity is between Africa and everywhere else. Not all diversity is equal or generates at the same rate either and the highest diversity genes tend to be the ones related to disease resistance /immune system functioning. Native Americans actually have several new alleles here that apparently evolved independently in the new world. When you talk about specific things like the MHC, they're still quite diverse and not too far off from similar European populations.
One thing that will be interesting to watch is the long term effect of modern medicine. You can't believe in darwin and think that relieving the selective pressure will have no consequences. By saving kids that merciless nature would have naturally killed, I think we are also "breeding" a human species that is inadapted to its environment, fragile. And I wonder if the high level of allergies seen in kids today isn't an early symptom of that.
Humans have a long history of relegating certain bodily functions to technology outside their bodies, to lower the requirements for survival.
Frying meat lowered requirements for the intestine, the immune system, and the teeth, compared to eating raw meat.
Baking bread lowered these requirements even further: old people who lost almost all teeth could now survive and be useful.
Various medical inventions saved innumerable lives, including some people who would otherwise die young, bur who lived enough to make a large impact on culture.
Probably this process will continue, producing a more fragile general population with more impressive outliers, and maybe even more (intellectually or otherwise) impressive baseline.
Genetic diversity is the way to go for resiliency.
If a species lives under constant, high selective pressure, it becomes highly adapted for the current environment. If the current environment changes a little -- too hot, too cold, more rain, less rain, a new disease evolves -- then the entire species becomes unfit for its new environment, and it may not survive long enough for new mutations to arise that happen to be better suited to the new environment.
If a species lives under weak selective pressure, it will only be weakly adapted to its current environment ... but it is much more likely that some part of it will be varied in a way that protects it or advantages it in the face of a changing environment. If selection pressure becomes harder -- if shit hits the fan -- it may be bad for a large chunk of the population, but it is more likely that at least some part of it will survive.
Take potatoes -- you fill a field full of genetically identical potatoes which are perfectly suited to the climate and conditions you're growing in, and you can get just monstrous yields. But if the slightest thing goes wrong, if a new blight takes hold, the entire crop can be lost to the last. The population is strong, but fragile.
And that is why eugenics is just so, so dumb, in addition to being, you know, ethically wrong.
Isn't that what has been happening since humans have existed? We have to wear clothes to live in most environments for instance, that is a good sign of not being naturally adapted.
> ... that is inadapted to its environment, fragile.
No. The "environment" of modern humans now includes modern medicine. Of course, if this aspect of the "environment" changes after awhile again, they would be more fragile than the current population in this respect on average. But the same is true for any (ancient) population confronted with new contexts. There is no fundamental difference between man-made environmental changes and natural ones.
As this article shows, with evolution it is hit-or-miss whether the response to a pathogen has collateral damage. In medicine, we can be more proactive about it.
Humanity isn't going to develop a widespread genetic resistance to TB in the near future that wipes out TB if we just let tons of people die from it. The idea that we are breeding weakness into society by using medicine and that we'd have a superior society by denying medicine to people is both medically wrong and frankly disgusting.
However, with modern high density cities and long distance travel, people are subjected to a much greater number of diseases than in pre-industrial times.
Humanity isn't going to develop a genetic resistance to TB in the near future if we just let tons of people die from it. The idea that we are breeding weakness into society by using medicine and that we'd have a superior society by denying medicine to people is both medically wrong and frankly disgusting.
The science is fascinating, the conclusions compelling, but why didn't these mutations appear during Justinian's Plague?[1] And if mutations helping resistance to plague were already present from 550AD, why was the Black Plague so devastating 800 years later? 800 years is plenty of time for the mutations to have spread to all of Europe, and yet Black Plague killed as much as 60% of the total European population.
Are we sure that no mutations exist from the Justinian? How genetically similar were the bacteria that caused the two plagues?
One theory off the top of my head, maybe Justinian affected elderly but not the young as much? If true, there would be little selective pressure applied.
Covid killed a lot of people even though we have at least four other coronaviruses running around causing common cold, and most of the victims had some banal coronavirus infection before.
The plague bacteria of 550 AD was probably not completely identical to the one in 1350 AD either.
> The plague bacteria of 550 AD was probably not completely identical to the one in 1350 AD either.
Both plagues were caused by the same bacteria, Yersinia pestis. I don't see how being "completely identical" would matter, only that it was the same species of bacteria.
Different strains of the same bacteria species can produce different immune responses, but if the species is pathogenic to humans, all its strains will also be considered the same pathogen. The Plague of Justinian and the Black Death were both known to be virulent in that they were both rapid, severe, and destructive, but virulence is not an objectively measurable quality.
Only women lose their ability to reproduce past a certain biological age (as opposed to chronological age), and I think you simply mean "those that didn't have children," of any age. But that is how natural selection works, random mutation during sexual reproduction in response to environmental pressure allowing differential survival and reproduction of individuals due to differences in inherited phenotypic traits. Those that died with or without children were not selected for survival as they usually would not have mutated beneficially after they were already conceived. We call that cancer.
800 years is also a lot of time for genetic drift to occur. If it’s not being actively selected for anymore, it can end up being in increasingly smaller parts of the population.
Genetic drift occurs due to random chance, unlike natural selection. Presumably, the population that survived Justinian's Plague had beneficial mutations. While it is possible that 40 generations is long enough for genetic drift as populations mix and become heterogeneous, the surviving population was homogeneous in regards to those beneficial mutations. The bacterium Yersinia pestis never actually went away, so plague deaths continued uninterrupted during those 800 years, just not at the level of pandemic. Those mutations would continue to be beneficial and those with them continued to be actively selected for survival.
Thanks for putting it as 800 years. In fact, we are closer to the black death now than they were to the justinian plague. Just a small thing that was interesting to notice.
'Survival of the Sickest' by Sharon Moalem covers this and several other diseases that are related to survival at a cost as well. Fun read for the interested!
I have very weird food autoimmune issues (sinus headaches from a lot of common stuff). Often when I say something about gluten people will bring up the relatively recent increase in intolerances. Some will point to genetically engineered crops, some to the use of glyphosate. I always thought maybe we had more variety and more awareness now (i.e. 1000 years ago my options would have been limited and I'd just suffer, now I have choice).
I saw this same article on NPR a few days ago and it is really cool that it might be a genetic adaptation. I almost never get sick (besides from food) so an overactive immune system would make sense.
There is also (sometimes contested) academic research about adherence to a gluten free diet having positive health outcomes for autism, schizophrenia, and bipolar disorder. The mechanism, as I've seen it explained, is that autistic people's bodies treat gluten / casein as an opiate (exorphine is the word they use) which mirrors my experience with sinus headaches (it feels like a withdrawal).
Wandering post to say this research is super exciting and there is a ton of crazy stuff around food.
The article literally says it's probably not going to happen.
> He said that it was unlikely that Covid-19 outbreak would shape our immune system in a similar way — largely because the disease predominantly kills people after their reproductive age, meaning it's unlikely genes that confer protection would be passed on to the next generation.
Covid kills old people, the disease needs to kill young people, before they have kids, to have an impact on the gene pool (unless other factors than Darwinism are at play in the evolution of genes).
Check out Dark Reader addon. https://darkreader.org/ Works in pretty much all browsers. On FF for Android it can even follow system settings for Dark Mode and for me only turn on between 20 and 6 o'clock.
I use brave on mobile which doesn't support extensions.
There is built-in chromium dark mode, which seems OK but its not possible to disable it per tab.
