Book Club: The 10,000 Year Explosion: pt 4 Agriculture

Welcome back to EvX’s Book Club. Today we’re discussing Chapter 4 of The 10,000 Year Explosion: Consequences of Agriculture.

A big one, of course, was plague–on a related note, Evidence for the Plague in Neolithic Farmers’ Teeth:

When they compared the DNA of the strain recovered from this cemetery to all published Y. pestis genomes, they found that it was the oldest (most basal) strain of the bacterium ever recovered. Using the molecular clock, they were able to estimate a timeline for the divergence and radiation of Y. pestis strains and tie these events together to make a new, testable model for the emergence and spread of this deadly human pathogen.

These analyses indicate that plague was not first spread across Europe by the massive migrations by the Yamnaya peoples from the central Eurasian steppe (around 4800 years ago)… Rascovan et al. calculated the date of the divergence of Y. pestis strains at between 6,000 and 5,000 years ago. This date implicates the mega-settlements of the Trypillia Culture as a possible origin point of Y. pestis. These mega-settlements, home to an estimated 10,000-20,000 people, were dense concentrations of people during that time period in Europe, with conditions ideal for the development of a pandemic.

The Cucuteni-Trypilia Culture flourished between the Carpathian Mountains and the Black Sea from 4800-3000 BC. It was a neolithic–that is, stone age–farming society with many large cities. Wikipedia gives a confused account of its demise:

According to some proponents of the Kurgan hypothesis of the origin of Proto-Indo-Europeans … the Cucuteni–Trypillia culture was destroyed by force. Arguing from archaeological and linguistic evidence, Gimbutas concluded that the people of the Kurgan culture (a term grouping the Yamnaya culture and its predecessors) … effectively destroyed the Cucuteni–Trypillia culture in a series of invasions undertaken during their expansion to the west. Based on this archaeological evidence Gimbutas saw distinct cultural differences between the patriarchal, warlike Kurgan culture and the more peaceful egalitarian Cucuteni–Trypillia culture, … which finally met extinction in a process visible in the progressing appearance of fortified settlements, hillforts and the graves of warrior-chieftains, as well as in the religious transformation from the matriarchy to patriarchy, in a correlated east–west movement.[26] In this, “the process of Indo-Europeanization was a cultural, not a physical, transformation and must be understood as a military victory in terms of successfully imposing a new administrative system, language, and religion upon the indigenous groups.[27]

How does it follow that the process was a cultural, not physical transformation? They got conquered.

In his 1989 book In Search of the Indo-Europeans, Irish-American archaeologist J. P. Mallory, summarising the three existing theories concerning the end of the Cucuteni–Trypillia culture, mentions that archaeological findings in the region indicate Kurgan (i.e. Yamnaya culture) settlements in the eastern part of the Cucuteni–Trypillia area, co-existing for some time with those of the Cucuteni–Trypillia.[4]Artifacts from both cultures found within each of their respective archaeological settlement sites attest to an open trade in goods for a period,[4] though he points out that the archaeological evidence clearly points to what he termed “a dark age,” its population seeking refuge in every direction except east. He cites evidence of the refugees having used caves, islands and hilltops (abandoning in the process 600–700 settlements) to argue for the possibility of a gradual transformation rather than an armed onslaught bringing about cultural extinction.[4]

How is “refugees hiding in caves” a “gradual transformation?” That sounds more like “people fleeing an invading army.”

The obvious issue with that theory is the limited common historical life-time between the Cucuteni–Trypillia (4800–3000 BC) and the Yamnaya culture (3300–2600 BC); given that the earliest archaeological findings of the Yamnaya culture are located in the VolgaDonbasin, not in the Dniester and Dnieper area where the cultures came in touch, while the Yamnaya culture came to its full extension in the Pontic steppe at the earliest around 3000 BC, the time the Cucuteni–Trypillia culture ended, thus indicating an extremely short survival after coming in contact with the Yamnaya culture.

How is that an issue? How long does Wikipedia think it takes to slaughter a city? It takes a few days. 300 years of contact is plenty for both trade and conquering.

Another contradicting indication is that the kurgans that replaced the traditional horizontal graves in the area now contain human remains of a fairly diversified skeletal type approximately ten centimetres taller on average than the previous population.[4]

What are we even contradicting? Sounds like they got conquered, slaughtered, and replaced.

Then Wikipedia suggests that maybe it was all just caused by the weather (which isn’t a terrible idea.) Drought weakened the agriculturalists and prompted the pastoralists to look for new grasslands for their herds. They invaded the agriculturalists’ areas because they were lush and good for growing grain, which the pastoralists’ cattle love eating. The already weakened agriculturalists couldn’t fight back.

ANYWAY. Lets get on with Greg and Henry’s account, The 10,000 Year Explosion:

The population expansion associated with farming increased crowding, while farming itself made people sedentary. Mountains of garbage and water supplies contaminated with human waste favored the spread of infectious disease. …

Most infectious diseases have a critical community size, a  number and concentration of people below which they cannot persist. The classic example is measles, which typically infects children and remains infectious for about ten days, after which the patient has lifelong immunity. In order for measles to survive, the virus that causes it, the paramyxovirus, must continually find unexposed victims–more children. Measles can only persist in a large, dense population: Populations that are too small or too spread out (under half a million in close proximity) fail to produce unexposed children fast enough, so the virus dies out.

Measles, bubonic plague, smallpox: all results of agriculture.

Chickenpox: not so much.

I wonder if people in the old Cucuteni–Trypillia area are particularly immune to bubonic plague, or if the successive waves of invading steppe nomads have done too much genetic replacement (slaughtering) for adaptations to stick around?

Harpending and Cochran then discuss malaria, which has had a big impact on human genomes (eg, sickle cell,) in the areas where malaria is common.

In general, the authors play it safe in the book–pointing to obvious cases of wide-scale genetic changes like sickle cell that are both undoubtable and have no obvious effect on personality or intelligence. It’s only in the chapter on Ashkenazi IQ that they touch on more controversial subjects, and then in a positive manner–it’s pleasant to think, “Why was Einstein so smart?” and less pleasant to think, “Why am I so dumb?”


It’s time to address the old chestnut that biological differences among human populations are “superficial,” only skin-deep. It’s not true: We’re seeing genetically caused differences in all kinds of functions, and every such differences was important enough to cause a significant increase in fitness (number of offspring)–otherwise it wouldn’t have reached high frequency in just a few millennia.

As for skin color, Cochran and Harpending lean on the side of high-latitude lightening having been caused by agriculture, rather than mere sunlight levels:

Interestingly, the sets of changes driving light skin color in China are almost entirely different from those performing a similar function in Europe. …

Many of these changes seem to be quite recent. The mutation that appears to have the greatest effect on skin color among Europeans and neighboring peoples, a variant of SLC24A5, has spread with astonishing speed. Linkage disequilibrium… suggests that it came into existence about 5,800 years ago, but it has a frequency of 99 percent throughout Europe and is found at significant levels in North Africa, East Africa, and as far east as India and Ceylon. If it is indeed that recent, it must have had a huge selective advantage, perhaps as high as 20 percent. It would have spread so rapidly that, over a long lifetime a farmer could have noticed the change in appearance in his village.


In humans, OAC2 … is a gene involved in the melanin pathway… Species of fish trapped in caves… lose their eyesight and become albinos over many generations. … Since we see changes in OCA2 in each [fish] case, however, there must have been some advantage in knocking out OCA2, at least in that underground environment. The advantage cannot like in increased UV absorption, since there’s no sunlight in those caves.

There are hints that knocking out OCA2, or at least reducing its activity, may he advantageous… in humans who can get away with it. We see a pattern that suggests that having one inactive copy of OCA2 is somehow favored even in some quite sunny regions. In southern Africa, a knocked-out version of OCA2 is fairly common: The gene frequency is over 1 percent.

And that’s an area with strong selection for dark skin.

A form of OCA2 albinism is common among the Navajo and other neighboring tribes, with gene frequencies as high as 4.5 percent. The same pattern appears in southern Mexico, eastern Panama, and southern Brazil. All of which suggests that heterozygotes…may ave some advantage.

Here is an article on the possibility of sexual selection for albinism among the Hopi.

So why do Europeans have such variety in eye and hair color?


The skeletal record clearly supports the idea that there has been rapid evolutionary change in humans over the past 10,000 years. The human skeleton has become more gracile–more lightly built–though more so in some populations than others. Our jaws have shrunk, our long bones have become lighter, and brow ridges have disappeared in most populations (with the notable exception of Australian Aborigines, who have also changed, but not as much; they still have brow ridges, and their skulls are about twice as thick as those of other peoples.)

This could be related to the high rates of interpersonal violence common in Australia until recently (thicker skulls are harder to break) or a result of interbreeding with Neanderthals and Denisovans. We don’t know what Denisovans looked like, but Neanderthals certainly are noted for their robust skulls.

Skull volume has decreased, apparently in all populations: In Europeans, volume is down about 10 percent from the high point about 20,000 years ago.

This seems like a bad thing. Except for mothers.

Some changes can be seen even over the past 1,000 years. English researchers recently compared skulls from people who died in the Black Death ([approximately] 650 years ago), from the crew of the Mary Rose,a  ship that sank in Tudor times ([approximately] 450 years ago) and from our contemporaries. The shape of the skull changed noticeably over that brief period–which is particularly interesting because we know there has been no massive population replacement in England over the past 700 years.

Hasn’t there been a general replacement of the lower classes by the upper classes? I think there was also a massive out-migration of English to other continents in the past five hundred years.

The height of the cranial vault of our contemporaries was about 15 percent larger than that of the earlier populations, and the part of the skull containing the frontal lobes was thus larger.

This is awkwardly phrased–I think the authors want the present tense–“the cranial vault of our contemporaries is…” Nevertheless, it’s an interesting study. (The frontal lobes control things like planning, language, and math.) 

We then proceed to the rather depressing Malthus section and the similar “elites massively out-breeding commoners due to war or taxation” section. You’re probably familiar with Genghis Khan by now. 

We’ve said that the top dogs usually had higher-than-average fertility, which is true, but there have been important exceptions… The most common mistake must have been living in cities, which have almost always been population sinks, mostly because of infectious disease. 

They’re still population sinks. Just look at Singapore. Or Tokyo. Or London. 

The case of silphium, a natural contraceptive and abortifacient eaten to extinction during the Classical era, bears an interesting parallel to our own society’s falling fertility rates. 

And of course, states domesticate their people: 

Farmers don’t benefit from competition between their domesticated animals or plants… Since the elites were in a very real sense raising peasants, just as peasants raised cows, there must have been a tendency for them to cull individuals who were more aggressive than average, which over time would have changed the frequencies of those alleles that induced such aggressiveness.

On the one hand, this is a very logical argument. On the other hand, it seems like people can turn on or off aggression to a certain degree–uber peaceful Japan was rampaging through China only 75 years ago, after all. 

Have humans been domesticated? 

(Note: the Indians captured by the Puritans during the Pequot War may have refused to endure the yoke, but they did practice agriculture–they raised corn, squash and beans, in typical style. Still, they probably had not endured under organized states for as long as the Puritans.)

There is then a fascinating discussion of the origins of the scientific revolution–an event I am rather fond of. 

Although we do not as yet fully understand the true causes of the scientific and industrial revolution, we must now consider the possibility that continuing human evolution contributed to that process. It could explain some of the odd historical patterns that we see.

Well, that’s enough for today. Let’s continue with Chapter 5 next week.

How about you? What are your thoughts on the book?


Prohibition part 2: Beer, Cholera, and Public Health

Part 1: Did European Filthiness lead to Prohibition?

So why were the immigrants drinking so much?

Simply put, European cities prior to the installation of underground sewers and water purification plants were disgusting, filth-ridden cesspools where the average citizen stood an astronomical chance of being felled by fecal-born diseases. How the cities got to be so revolting is beyond me–it may just be a side effect of living in any kind of city before the invention of effective sewers. Nevertheless, European city dwellers drank their own feces until everyone started catching cholera. (Not to mention E. coli, smallpox, syphilis, typhus, tuberculosis, measles, dysentery, Bubonic Plague, gonorrhea, leprosy, malaria, etc.)

The average superstitious “primitive” knows that dead bodies contain mystical evil contamination properties, and that touching rotting carcasses can infect you with magical death particles that will then kill you (or if you are a witch, your intended victims,) but Europeans were too smart for such nonsense; Ignaz Semmelweis, the guy who insisted that doctors were killing mothers by infecting them with corpse particles by not washing their hands between autopsying dead bodies and delivering babies, was hauled off to an insane asylum and immediately stomped to death by the guards.

The women, of course, had figured out that some hospitals murdered their patients and some hospitals did not; the women begged not to be sent to the patient-murdering hospitals, but such opinions were, again, mere superstitions that the educated classes knew to ignore.

It is amazing what man finds himself suddenly unable to comprehend so long as his incomprehension is necessary for making money, whether it be the amount of food necessary to prevent a child from starving or that you should not wallow in feces.

Forgive me my vitriol, but there are few things I hate worse than disease, and those who willfully spread death and suffering should be dragged into the desert and shot.

Cleanliness is next to Godliness.

Anyway, back to our story. The much-beleagured “Dark Ages” of Medieval Europe was actually a time of relatively few diseases, just because the population was too low for much major disease transmission, but as the trade routes expanded and cities grew, epidemic after epidemic swept the continent. The Black Death came in 1346, carrying off 75 to 200 million people, or 30-60% of the population. According to the Wikipedia, “Before 1350, there were about 170,000 settlements in Germany, and this was reduced by nearly 40,000 by 1450.” The Black Plague would not disappear from Europe until the 1700s, though it returned again around 1900–infecting San Francisco at the same time–in the little known “Third Plague” outbreak that killed approximately 15 million people, (most of them in India and China,) and officially ended in 1959.

(BTW, rodents throughout much of the world, including America, still harbor plague-bearing fleas which do actually still give people the plague, so be cautious about contact with wild rodents or their carcases, and if you think you have been infected, get to a hospital immediately because modern medicine can generally cure it.)

Toward the end of the 1700s, smallpox killed about 400,000 Europeans per year, wiping out 20-60% of those it infected.

Cholera spreads via the contamination of drinking water with cholera-laden diarrhea. Prevention is simple: don’t shit in the drinking water. If you can’t convince people not to shit in the water supply, then boil, chlorinate, sterilize, filter, or do whatever it takes to get your water clean.

In 1832, Cholera struck the UK, killing 53,000 people; France lost 100,000. In 1854, epidemiologist John Snow risked his life to track the cholera outbreak in Soho, London. His work resulted in one of history’s most important maps:


Each black line represents a death from cholera.

The medical profession of Snow’s day believed that cholera was spread through bad air–miasmas–and that Snow was a madman for being anywhere near air breathed out by cholera sufferers. Snow’s map not only showed that the outbreak was concentrated around one water source, (the PUMP in the center of the map,) but also showed one building on Broad street that had been mysteriously spared the contagion, suffering zero deaths: the brewery.

The monks of the brewery did not drink unadulterated water from the pump; they were drinking beer, breakfast, lunch, and dinner. Drinking nothing but beer might sound like a bad strategy, especially if you need to drive anywhere, but beer has a definite advantage over water: fermentation kills pathogens.

It wasn’t until 1866 that the establishment finally started admitting the unpleasant truth that people were catching cholera because they were drinking poop water, but since then, John Snow’s work has saved the lives of millions of people.

Good luck finding anyone who remembers Snow’s name today–much less Semmelweis’s–but virtually every school child in America knows about Amelia Earhart, a woman who’s claim to fame is that she failed to cross the Pacific Ocean in a plane. (Sorry, I was looking at children’s biographies today, and Amelia Earhart remains one of my pet peeves in the category of “Why would I try to inspire girls via failure?”)

But that is all beside the point, which is simply that Europeans who drank lots of beer lived, while Europeans who drank water died. This is the sort of thing that can exert a pretty strong selective pressure on people to drink lots of beer.

Meanwhile, Back in America…

While Americans were not immune to European diseases, lower population density made it harder for epidemics to spread. The same plague that killed 13 million people in China and India killed a mere couple hundred in San Francisco, and appears to have never killed significant numbers in other states.

Low population density meant, among other things, far less excrement in the water. American water was probably far less contaminated than European water, and so Americans had undergone much less selective pressure to drink nothing but beer.

Many American religious groups took a dim view of alcohol. The Puritans did not ban alcohol, but believed it should be drunk in moderation and looked down on drunkenness. The Methodists, another Protestant group that broke away from the Anglican Church in the late 1700s and spread swiftly in America, were against alcohol from their start. Methodist ministers were to drink chiefly water, and by the mid-1880s, they were using “unfermented wine” for their sacraments. The Presbyterians began spreading the anti-alcohol message during the Second Great Awakening, and by 1879, Catherine Booth, co-founder of the Salvation Army, claimed that in America, “almost every [Protestant] Christian minister has become an abstainer.” (source) Even today, many Southern Baptists, Mormons, and Seventh Day Adventists abstain entirely from alcohol, the Mormons apparently going so far as to use water instead of wine in their sacraments.

Temperance movements also existed in Europe and other European colonies, but never reached the same heights as they did in the US. Simply put, where the water was bad, poor people could not afford to drink non-fermented beverages. Where the water was pure, people could claim drinking it a necessary piece of salvation.

As American cities filled with poor, desperate foreigners fleeing the famine and filth of Europe, their penchant for violent outbursts following over-indulgence in alcohol was not lost on their new neighbors, and so Prohibition’s coalition began to form: women, who were most often on the receiving end of drunken violence; the Ku Klux Klan, which had it out for foreigners generally and Papists especially; and the Protestant ministers, who were opposed to both alcoholism and Papism.

The Germans were never considered as problematic as the Irish, being more likely to be employed and less likely to be engaged in drunken crime, but they held themselves apart from the rest of society, living in their own communities, joining German-specific social clubs, and still speaking German instead of English, which did not necessarily endear them to their neighbors.

Prohibition was opposed primarily by wealthy Germans, (especially the brewers among them;) Episcopalians, (who were afraid their sacramental wine would be banned;) and Catholics. The breweries also campaigned against Women’s Suffrage, on the grounds that pretty much all of the suffragettes were calling for Prohibition.

WWI broke the German community by making it suddenly a very bad idea to be publicly German, and people decided that using American grain to brew German beer instead of sending that grain to feed the fighting men on the front lines was very unpatriotic indeed. President Wilson championed the income tax, which allowed the Federal Government to run off something other than alcohol taxes, women received the right to vote, and Prohibition became the law of the land–at least until 1933, when everyone decided it just wasn’t working out so well.

But by that time, the drinking water problem had been mostly worked out, so people at least had a choice of beverages they could safely and legally imbibe.

Part 1 is here.