How the ‘black death’ left its genetic mark on future generations

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.

https://psmag.com/news/how-native-american-genes-tell-the-st...

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.

https://www.goodreads.com/book/show/39020.1491

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.

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.

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.

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.

The plague bacteria of 550 AD was probably not completely identical to the one in 1350 AD either.

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.

> 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.