Hunters, Gatherers, Growers and Gods
http://www.fsmitha.com/h1/ch00.htm

"Farming created more food, and more food made possible more people. More people kept farming communities on the brink of inadequate nutrition. And farmers were more dependent on nature than were hunter-gatherers, who were free to drift from drought to areas that had more game and wild foods. Domesticated plants were vulnerable to insect ravages in ways that wild plants were not. Archaeologists have found in the bones of children in agricultural societies more signs of malnutrition than that of people living from hunting and gathering, and the average height of early farming populations has been discovered to be shorter than that of hunter-gatherers."

the important thing about farming is that beyond the short term it tended to result in a major decrease in the diversity of foods consumed. the caloric intake might have been somewhat lower, but the biggest thing might be the general skew toward starch as the major source of calories, and the decrease in a diversity of vitamins and the proportion of fats and proteins in the diet. obviously farming resulted in a greater net productivity for a given area, and i think one might make an argument that the variance in caloric intake might have been lower over the long term. but in terms of quality there was a sharp reduction. i think most agricultural populations evolved to the monotonous high carb diet over time, but, human biochemistry has its limits, the underfed farmer might do a lot better on the wheat/rice regime than a hunter-gatherer, but the hunter-gatherer still did better on average because of the complementation in their nutrition.

I'm searching for the link but dang I can't find it. Early farming communities were also ravaged by far more disease than hunter gatherers. I would imagine that quite a few pathogens suddenly found a target rich environment. Morover its only been a few thousand years since civ began. We might not have had time to develop completely effective immune responses to these yet.

An example
Autism and Schiz triggered by mothers own immune response
http://www.autismconnect.org/new...pe=news& id=6252

Our immune system works, but it would probably work a lot better if we had a few thousand more years to evolve in cities.

but it would probably work a lot better if we had a few thousand more years to evolve in cities.

1) urbanization has been a minority phenomena for most of human history.

2) that minority probably contributed a lower than expected amount to ancestry because of low fertility, etc.

3) so most adaptive evolution is on the scale of dense villages, not cities.

4) signatures of natural selection over the last 10 K in humans also show results around areas with immune implications. also some stuff with metabolism.

One distinctive feature of agricultural society is the existence of economic surplus, and if this is a driving force of organisation and behaviour, the consumption society may be closer to agricultural than hunter-gatherer society.

One distinctive feature of agricultural society is the existence of economic surplus, and if this is a driving force of organisation and behaviour, the consumption society may be closer to agricultural than hunter-gatherer society.

this is good point, except that most of these societies are on the malthusian edge. the surplus is used by a small minority. the typical farmer didn't have surplus. that being said

1) the ones who monopolized the surplus had more descendants

2) but, these (the elites) also tended to be more embedded in the structures which stabilized a neolithic society. e.g., arranged marriage was more of an issue among elites who had assets and power which were relevant to a match. and obviously institutional religion was also more of an elite affair until lately.

and of course, though farmers might have had more surplus in terms of primary production (they could store their grain) and goods (e.g., pottery) than hunter-gatherers, the latter had way more surplus of leisure time. additionally, i think one could argue that hunter-gatherers had more discriminatory choice in what they had control over re: production. that is, what they would hunt for, what they would gather. variety in choices for agriculturalists is more of a factor among elites, it seems that farmers tended to make due with a narrow range of goods and services (often since the production was local and not very specialized there was only one choice).

The mobility of today is more analogous to hunter gatherers than agriculturalists. Agriculturalists tended to live on the same land for generations, while hunter gatherers and urban workers must move to find the most exploitable region. I see what you mean about more transient mating patterns as well.

Agriculturalists tended to live on the same land for generations, while hunter gatherers and urban workers must move to find the most exploitable region.

true. but what are the numbers re: person-to-person contact? modern workers encounter orders of magnitude more people in their lives than farmers or hunter-gatherers. what is the relationship between the last two? i think they're within the same order of magnitude, though an anthro guy should speak up.

re: mating patterns, this to me is one of the major ways i think americans are more like hunter-gatherers than the typical eurasian of 500 years ago. though arranged marriages were often only in vogue among elites, peasants were very practical in choosing a partner (e.g., "hard worker"). i'm not sure hunter-gatherers are so fixated on this since their bonds are often more transient, they can choose more whimsically.

Agricultural societies tend to wipe out hunter-gatherer societies in unholy bloodbaths, despite nutrional differences. But we've got the best of both worlds now.

Ahh...to recall those transient, whimsical, bondings of my youth.

Definitely used to be a hunter-gatherer, now in more of an agricultural-type of arrangement.

I guess this is because I reaped what I sowed...

Agricultural societies tend to wipe out hunter-gatherer societies in unholy bloodbaths, despite nutrional differences. But we've got the best of both worlds now.

more complicated, at least over the long term. it seems like most europeans are descendants of hunter-gatherers who picked up the lifestyle of agriculturalists. that is, 3 out of 4 ancestors of europeans were probably not neolithic farmers who started the 'wave of advance.' i suspect that those who did pick up agriculture increased population size and so absorbed/eliminated their hunter-gatherer rivals though. the absorption of hunter-gatherers on the wave of advance is pretty obvious in other regions. e.g., the xhosa in south africa are obviously admixed with the local khoisan. the japanese seem to be about 1/4 'jomon,' that is, the hunter-gatherers who lived on japan before the rice farmers came from korea.

the contact with the new world and australia are reductio ad absurdums of what happens when ag people meet hunter-gatherers. but in eurasia proper it was probably more of a wave of advance where assimilation was more important than extermination.

p.s. i am open to the possibility that the rise of disease among ag peoples 'cleared the way' for their advance in places like europe.

Razib -

Re: your 5:59 comment, I have two thoughts -

1) I wonder how geographically/historically broad the oft-cited result of cities being net population sinks is? From first principles you'd expect much higher disease mortality, maybe lower fertility maybe not (depending on the nature of the urban economy and its ability to utilize additional labor inputs). I recall reading (yeah, I know, I should have a cite and my typically useless search skills cannot locate the cite) a demographic study of high Tokugawa Japan (mid - late 18thC) which concluded that based on at least children surviving to adulthood the cities were much better than the countryside - attributed to a combination of surprisingly good sanitation and food supplies in the urban areas and a taxation regime which made it easier for urban artisan/merchant to retain a little bit of surplus (especially to accumulate surplus across generators) than the successful peasant. Rather an outlier I suspect.

2) Even granted that in most cases cities were population sinks, it doesn't necessarily follow that "most adaptive evolution is on the scale of dense villages, not cities", does it? Selection pressure could easily still have been much higher in cities than villages - allele fixation could have first occurred in the urban areas (e.g. Cochran-Hardy-Harpending, though I suppose it's possible that the fixation occured in the subpopulation of Ashkenazi that were living in villages).

empiricus, you bring up interesting points.

A little long but interesting.

"Another example of paleopathology at work is the study of Indian skeletons from burial mounds in the Illinois and Ohio river valleys. At Dickson Mounds, located near the confluence of the Spoon and Illinois rivers, archaeologists have excavated some 800 skeletons that paint a picture of the health changes that occurred when a hunter-gatherer culture gave way to intensive maize farming around A. D. 1150. Studies by George Armelagos and his colleagues then at the University of Massachusetts show these early farmers paid a price for their new-found livelihood. Compared to the hunter-gatherers who preceded them, the farmers had a nearly 50 per cent increase in enamel defects indicative of malnutrition, a fourfold increase in iron-deficiency anemia (evidenced by a bone condition called porotic hyperostosis), a theefold rise in bone lesions reflecting infectious disease in general, and an increase in degenerative conditions of the spine, probably reflecting a lot of hard physical labor. "Life expectancy at birth in the pre-agricultural community was bout twenty-six years," says Armelagos, "but in the post-agricultural community it was nineteen years. So these episodes of nutritional stress and infectious disease were seriously affecting their ability to survive."

"Greg Clark reports that most of the gains in income due to increased economic efficiency have gone to unskilled laborers over the past few centuries; we live in a relatively egalitarian age in many ways."

I can attest to that. I used to work in an office doing technical work and made a middle class living. I quit and started a landscaping company. Even if I did all the physical work myself (which I don't) guess which one pays more?

Knowing how to operate a computer?
Knowing how to operate a rake?

If your guess is rake you are correct.

I recall reading (yeah, I know, I should have a cite and my typically useless search skills cannot locate the cite) a demographic study of high Tokugawa Japan (mid - late 18thC) which concluded that based on at least children surviving to adulthood the cities were much better than the countryside - attributed to a combination of surprisingly good sanitation and food supplies in the urban areas and a taxation regime which made it easier for urban artisan/merchant to retain a little bit of surplus (especially to accumulate surplus across generators) than the successful peasant. Rather an outlier I suspect.

your stuff about japan rings true with what i know reading clark's stuff as well as other material. the cities of japan were very modern and efficient during the tokugawa period. that being said, i think this is a 'best case scenario' (obviously tokugawa japan was rather stable and well run compared to most pre-modern states).

Even granted that in most cases cities were population sinks, it doesn't necessarily follow that "most adaptive evolution is on the scale of dense villages, not cities", does it?

assume two demes:

city & country

city as higher selection than country for allele x in the initial genetic background. city fixes first, country fixes later. but this is the thing: city only maintains its population via migration from country, and city dwellers do not reproduce at replacement. in other words, unless there are meta-population dynamics (group level effects, etc.) the city's evolution is epiphenomenal since the longer a lineage identical by descent resides in the city the more likely it is to go extinct.

now, if allele x1 and allele x2 are differentially selected then you can imagine an equilibrium that is obtained of the two alleles in the city and the country determined by the rate of migration from the country. in this case the country is still more relevant because 9/10 of population is resident there.

re: meta-population dynamics, it doesn't have to be group selection. imagine that the city serves as a necessary reservoir for diseases when they are in their non-pandemic phase. one can imagine that a purely rural society might not have the ecological diversity necessary for the perpetuation of particular diseases. in this case cities and their populations serve as important factors in the long term evolution of the region, though mostly by serving as part of the selective background of the country.

just some thoughts.

A little long but interesting.

might be an extreme case. one imagines that early agricultural populations might be under the most stress as they are the least adapted genetically and culturally to the new lifestyle. by early i'm not talking the first few generations, one can imagine that the wave of advance of agriculture was initially characterized by plentitude and high rates of population growth because of exploitation of virgin land. think of the american frontier farmers during the colonial period. the problem is that when the land gets filled up farmers are caught in the malthusian trap as they can't just move onto better land. at this point though they can't switch back to hunter-gathering because of population sizes and transformation of the local environment (cutting down forests for fields, the extinction of prey and the marginalization of wild plant foods).

razib

When you consider that humans spent around 250,000 years living as hunter gatherers and only 5,000 to 10,000 years as farmers shouldn't we still be optimized for hunting gathering?

I'm not suggesting there hasn't been selection towards a farming/village economy but wouldn't it be minimal? How fast can positive mutations occur and then spread?

re: mating patterns, this to me is one of the major ways i think americans are more like hunter-gatherers than the typical eurasian of 500 years ago. though arranged marriages were often only in vogue among elites, peasants were very practical in choosing a partner (e.g., "hard agree wworker"). i'm not sure hunter-gatherers are so fixated on this since their bonds are often more transient, they can choose more whimsically.

i don't know if this really hobbles your thesis, but i don't think the bonds in hunter-gatherer societies were that transient. i thought most were patrilocal so the dudes would live pretty much all their lives with their own folks, and would have a hard time striking out on their own (someone with better information, please correct me). also, a lot of these societies do have arranged marriages , such as the !kung (though, according to this link, the !kung also have high divorce rates and bride-capture, so make of it what you will: http://drleannawolfe.com/kung.html).

When you consider that humans spent around 250,000 years living as hunter gatherers and only 5,000 to 10,000 years as farmers shouldn't we still be optimized for hunting gathering?

well, since the typical farming diet is still probably less healthy than an HG diet, more or less. but, this might be less adaptation than functional constraints (humans can't generate some vitamins endogenously no matter how many millions of years you give them).

How fast can positive mutations occur and then spread?

lactase persistence went from 0 to 95% in less than 5,000 years in europe. we have genetic data from subfossils that it wasn't there 7,000 years ago, and i assume it increased in frequency very fast to hit around 95% (it is 'dominant' in transmission so it would hit a 'wall' as most copies would be in heterozygotes at that frequency).

though, according to this link, the !kung also have high divorce rates and bride-capture, so make of it what you will

that's what i'm talking about. also, re: arranged marriages, the sample space of possible mates is pretty small for many HG groups. i'm not sure that 'arranged' vs. 'choice' is a good dichotomy. rather, i'm just implying that baroque and fixed social controls are less in place in these societies than in neolithic ones. the key issue is that in neolithic societies tragic lovers are murdered because their choices undermine the inflexible social order. they aren't murdered because they harm someone, or engage in deceit, rather, their choices are subordinate to the needs of their clan or social group. this sort of straight-jacket control seems less operative among both HG and moderns.

I read everywhere that cities were population sinks, but I've also read that Jewish populations were primarily urban through the middle ages and the Jewish population underwent rapid demographic growth between 1400 and 1900. For certain populations, cities must have allowed for growth, rather than being a demographic death spiral for any and all.

, but I've also read that Jewish populations were primarily urban through the middle ages and the Jewish population underwent rapid demographic growth between 1400 and 1900.

they weren't farmers. but that doesn't mean they all lived in crackow.

Razib, reading through this thread, I had the same thought as King M. I don't think that comparisons to crackow have any explanatory power. All descriptions of Jewish living environments that I've read on gnxp.com assume that Jews lived in substantially greater numbers in urban areas than in rural areas, particularly in proportion to the surrounding gentile populations. But their numbers increased in more or less the same proportion to gentiles' numbers in Europe. I've looked for cites but haven't found them.