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Comment by HarryHirsch | Hacker News Reader

So - how did this virus spread through the population? 20 kyrs ago people didn't live in cities but in small bands of a few dozen people. It's easy to see how an epidemic might spread through a village but how would it move between isolated groups?

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Groups interacted with each other. A large reason that humans are found more or less everywhere on the planet was pressure from interacting with other humans.

They absolutely did but how frequently? The first villages in China are attested 7500 BCE, that's 10 kyr later, if the dating is correct.

As far as I am aware, large meetings of different tribes did occur during the paleolithic at regular intervals, although not very frequently. In any case, such meetings don't have to be frequent for such a virus to spread once they do occur. The virus could have originated in a single tribe, killing some of the people and immunising others and then remained endemic in that tribe for years before they came into contact with others.

> They absolutely did but how frequently? The first villages in China are attested 7500 BCE, that's 10 kyr later, if the dating is correct.

There were obviously viruses before urbanization (especially given there are viruses that spread in wild animal populations), they probably just spread more slowly. At the minimum, there was probably regular deliberate contact/mixing between adjacent groups to avoid too much inbreeding, and that would imply other social contacts (e.g. an adult who married into another group returning home to catch up with his/her parents and old friends).

https://en.wikipedia.org/wiki/Fission%E2%80%93fusion_society...

Nitpicking here, but there probably wasn’t anything we would define as “marriage”. That Wikipedia article says “copulate” instead. Now I want to go down the wiki rabbit hole about the history of human marriage.

Also, I’d imagine there were at least far fewer viruses before urbanization. My understanding is early civilization was really good for diseases.

Early civilization would have been brutal in terms of diseases compared to today.

There are plenty of diseases where humans are a part of the reproduction cycle - malaria is a good example. You don’t need groups of humans together.

Then add in human-animal transmission and you have endemic malaria, tuberculosis, parasites, disease causing bacteria. If you look at remote, isolated tribes today they have a very heavy burden of non-fatal (but quality of life decreasing) diseases.

> Nitpicking here, but there probably wasn’t anything we would define as “marriage”. That Wikipedia article says “copulate” instead.

That specific passage was talking about chimpanzees.

There are certainly older settlements (not just remains) in the americas, australiasia, India and of course Africa. Undoubtably older ones in China too, just no traces yet found.

Genetic and linguistic studies demonstrate significant mixing of communities.

Human civilization was probably much more developed back then than 'experts' believe. Look at a satellite map, most of that light blue you see was land during that time. The East China sea was mostly land. You think people, like the majority of people, weren't living there?

Just look at the gobekli tepe story.

Maybe the virus was not a pandemic 20k years ago. Small tribes that carried genes that are resistant to the coronaviruses spread later on as they established larger communities/cities.

They were less "isolated" than you imagine. They traded with each other, intermarried, fought wars. You can see that in populations having a similar life style nowadays (there's very few of them now).

The same way the infectious face cancer spreads among the Tasmanian devils.

I’m not an expert but scientists have found that coronaviruses are aerosolized. So i think the process of aerosolization probably played a part.

Source for reference: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7293495/

I don't think aerosolization matters when you're not in the same building and you're any reasonable distance away (certainly when you're miles away from the closest infected, you're safe, right?)

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