Why Cities?

[Lorizael]

John Green goes over the evidence that, at least in the short term, moving from hunter-gatherer life to city life was a bad choice for most humans. They worked more, they ate worse, they were more susceptible to disease, etc. And yet people still did it anyway, and obviously we have civilization now because of that choice. But no prehistoric human made the choice because they knew their great^n grandchildren would thank them. So why'd it happen?

[Ming]

Booze...

[Dauphin]

First reaction - common defence, trade and access to necessary resources. Haven't watched the video, so I may be misinformed.

There is also some interesting maths around the number of cities in a given population range in a given geographic area. Think it was a geometric series. So you may be able to analyse it as a natural equilibrium issue rather than a narrow set of volatile variables in an individual person's decision.

[Dauphin]

Was it Zipf I'm thinking of?

[Lorizael]

Zipf shows up everywhere, but not entirely sure how that would feature here. Something like... the 2nd most common population size for a city shows up 1/2 as often as the most common population size?

Something that comes to mind when you talk about cities of differing sizes is that the archaeological record probably doesn't preserve proto-cities as well as more mature ones. So there has to be some continuum between campsite and Ur where the individual choice made is not... do I give up the hunter-gatherer life for this strange new city life... but something along the lines of... oh it just makes sense for me to stick around here for a season or two because those raiders from over the mountains have been acting up.

[Jon Miller]

Hunter-gatherers can't really fight and will always lose out to people in cities.

JM

[BeBMan]

Obviously cities because ppl didn't want to live in some rural backwater without internet and pizza service.

[Dinner]

There is safety in numbers plus group projects such as irrigation or city walls become possible. Those are highly valuable things which most people want.

[Elok]

Hunter-gatherers can't really fight and will always lose out to people in cities.

JM

I wouldn't say always, but in most cases. If you include nomadic pastoralists with hunter-gatherers (as "non-city-dwellers"), the historical scales even considerably. Of course, that's only true after the discoveries of horseback riding and archery, so not really applicable to the paleolithic or neolithic. At any rate, I think the more decisive factor is city-dwellers' superior ability to extract wealth from the land. You can support far more people per acre with farming than you can with hunting.

[Jon Miller]

Yes, and more people means better at a fight. Pastoralists later could do even better at times, but this was due to building on city-dwellers and could not exist in a vacuum.

I am currently reading Guns/Germs/Steel so I admit I am being influenced.

JM

[Lorizael]

At any rate, I think the more decisive factor is city-dwellers' superior ability to extract wealth from the land. You can support far more people per acre with farming than you can with hunting.

Land scarcity is a relatively recent phenomenon, because population densities were much, much lower in the past. (Yes, obviously, that's not unrelated to there being farming/cities now.)

[Lorizael]

Hunter-gatherers can't really fight and will always lose out to people in cities.

JM

Ah, but why the first city?

[Elok]

A college professor of mine advanced the theory that it happened due to a worldwide drought/famine called the Younger Dryas, when farming (generally involving exploitation of existing stands of mutated wheatgrass) was the only practical way to obtain the necessary amounts of food. And, of course, it only needs to happen in a few places, a couple of times, before the chain reaction sets in and civilization steamrolls the aboriginals.

[Lorizael]

A college professor of mine advanced the theory that it happened due to a worldwide drought/famine called the Younger Dryas, when farming (generally involving exploitation of existing stands of mutated wheatgrass) was the only practical way to obtain the necessary amounts of food. And, of course, it only needs to happen in a few places, a couple of times, before the chain reaction sets in and civilization steamrolls the aboriginals.

Looking into that, there's a Wikipedia article which cites this article discussing the controversial aspects of that theory.

http://science.sciencemag.org/content/327/5964/404.full

Despite the Younger Dryas's 20-year run as a leading explanation for the rise of agriculture, many scientists remained skeptical, and the idea has come under increasing attack. “The so-called impact of the Younger Dryas was always a matter of belief, not a matter of science,” says Valla. Archaeobotanist George Willcox of the Archéorient research center in Jalès, France, says that “there is only one site where [the younger Dryas explanation] could possibly work, and that's not enough.” That site is Abu Hureyra, but Willcox isn't convinced that the nine fat rye seeds reported there really represent domesticated grain. “There are so few of them,” he says, adding that “the general consensus is that plump grains are not good evidence for domestication.”

Other archaeologists see little evidence that the Late Natufians actually faced an environmental crisis. Archaeologist Nicholas Conard of the University of Tübingen in Germany and his co-workers have found considerable evidence at Baaz rock shelter in Syria that Natufians ate freshwater fish, which points “to the presence of stable sources of flowing water at a time when we are supposed to be in an environmental crisis due to aridity.”

And newer calibrated radiocarbon dating suggests that the Natufians did reasonably well during the entire Younger Dryas, Grosman argued in a talk here. The calibrated dates now stretch the Natufian period from about 2300 uncalibrated years to well over 3000 calibrated years and make the Late Natufian even longer than the Early Natufian. To have survived the return to harsh conditions for so long, Rosen says, the Late Natufians must have had a “stable adaptation” to the Younger Dryas. Moreover, Munro says, the increased mobility of the Late Natufian was not a likely “trigger for agriculture” and may have in fact postponed it.

[Dauphin]

Zipf shows up everywhere, but not entirely sure how that would feature here. Something like... the 2nd most common population size for a city shows up 1/2 as often as the most common population size?

My point was that if you started with one city of 10,000,000 people, and the countryside was empty, you'd probably see people spread out to fill the available land, and smaller towns and cities would arise along trade nodes creating by various resources being exploited or locally defensible landscapes being developed.

Similarly, if you had 10,000,000 people all living in their own homestead, then you'd probably find many of them would start to coalesce into villages and towns for trading, and then cities and so on.

Choosing to move down to a village/homestead, or up to a city, would be subject to a dynamic equilibrium because the system will tend to a position where you have the full spectrum of settlement size in statistically quantified proportions. Too many in the city such that country living is a better choice? Then people will leave. And vice versa. Variables such as technology are what scales and skews the system.