The Greatest Generation

When you compare our trifling selves with the generation that landed in Normandy, invented the atomic bomb, and wrote The Big Sleep, it doesn’t look good. You could easily get the impression that the United States went straight from a Golden Age to one of cardboard, skipping silver and all the other metals.

But  when you consider that people must have had 48 chromosomes back then, rather than the current measly 46, much is explained.

Theophilus Painter, a prominent cytologist, had investigated human chromosome number in 1923. He thought that there were 24 in sperm cells, resulting in a count of 48, which is entirely reasonable. That is definitely the case for all our closest relatives (chimpanzees, bonobos, gorillas, and orangutans).

The authorities say that that Painter made a mistake, and that humans always had 46 chromosomes. But then, for 30 years after Painter’s work, the authorities said that people had 48.  Textbooks in genetics continued to say that Man has 48 chromosomes up until the mid 1950s.  Many cytologists and geneticists studied human chromosomes during that period, but they knew that there were 48, and that’s what they saw. Now they know that there are 46, and that’s what every student sees.

Either the authorities are fallible and most people are sheep, or human chromosome number actually changed sometime after World War II.  No one could believe the first alternative: it would hurt our feelings, and therefore cannot be true.  No, we have a fascinating result: people today are fundamentally different from the Greatest Generation, biologically different: we’re two chromosomes shy of a load. .    So it’s not our fault !

Posted in Genetics | 108 Comments

The Germ of Laziness

That happens to be the title of a pretty interesting book about hookworm in the US.  The book was fine, but the story is better.

Hookworms are parasitic nematodes that take up residence in the small intestine and drink your blood.  Getting there is complicated. Eggs are shed in the stool, hatch in to larvae in suitable soil, and enter the next host through bare feet. They then migrate (through the blood stream)  to the lungs, then to the trachea, where they are swallowed and eventually reach the small intestine.

Enough of them can cause significant blood loss and serious anemia.

They have been a particular problem among miners, wading in wet tunnels, and an epidemic among workers  in an Italian railway tunnel 1880 led to general medical understanding – other people had  figured some of this out earlier, sometimes much earlier (Theodor Bilharz, even Avicenna!) but that knowledge did not become general.

Charles Wardell Styles , who had studied  parasitology at the Institute Pasteur and gotten his Ph.D. at Leipzig, discovered that hookworm was common in the American South.  People thought differently in those days: he tried to abolish hookworm.  That was harder that he expected.  Southerners claimed that they couldn’t possibly have such a disgusting problem – it was just Yankee slander.  M.D.s ( back then, before the Flexner reforms, med school was often a six-month course) pointed out that he wasn’t even a doctor, so why should they listen to him?  After giving one talk, two M.D.s wondered if actually getting  rid of hookworm, curing the disease –  wouldn’t that cut into their practice?  And while he didn’t kill them on the spot, I guarantee he considered it.

Some company towns embraced hookworm eradication – they figured that outhouses and shoes were cheap, easily paid for by greater worker productivity. So various political types decided that he was a tool of the Interests, and therefore bad.

Somehow this idea reached the then-new Rockefeller foundation.  They did it right. They made sure that Charles Wardell Styles was not the public face of their effort – because he didn’t suffer fools gladly, and they needed someone who positively enjoyed them, someone who could get along with the general public. They went from town to town, rather like a revival, giving people fairly unpleasant chemicals that really did get rid of most of the hookworms. Since they are small( ~1 cm) and unspectacular, they kept dead giant roundworms (up to a foot long) in a bottle and pretended that they’d been expelled from the locals. They told people to use an outhouse and wear shoes – which led some  to claim that this was all an elaborate plot by John D. Rockefeller to sell shoes to innocent Southerners.  On the positive side, someone came up with the idea that the South would have won the War, except for hookworm : then worming folks was a tribute to the Lost Cause.

It worked.  Not perfectly, but well: greatly decreasing worm burden was good enough, since when it comes to hookworm, the dose makes the poison. A few may even be good for you, if you buy into the hygiene hypothesis.

There was another effect: it damaged the competitive position of black farmers.  They’re a good deal more resistant to hookworm (it came with them, probably), and hookworm resistance was likely one of the reasons for higher labor productivity among black farmers. Reducing and then eliminating malaria had the same effect.

Posted in Uncategorized | Tagged | 78 Comments

Déjà Vu all over again: America and Europe

In terms of social organization and technology, it seems to me that Mesolithic Europeans (around 10,000 years ago) were like archaic Amerindians before agriculture.  Many Amerindians on the west coast were still like that when Europeans arrived – foragers with bows and dugout canoes.

On the other hand,  the farmers of Old Europe were in important ways a lot like English settlers: the pioneers planted wheat, raised pigs and cows and sheep,  hunted deer, expanded and pushed aside the previous peoples, without much intermarriage.  Sure, Anglo pioneers were literate, had guns and iron, were part of a state, all of which gave them a much bigger edge over the Amerindians than Old Europe ever had over the Mesolithic hunter-gatherers and made the replacement about ten times faster – but in some ways it was similar. Some of this similarity was the product of historical accidents: the local Amerindians were thin on the ground, like Europe’s Mesolithic hunters – but not so much because farming hadn’t arrived (it had in most of the United States), more because of an ongoing population crash from European diseases.

On the gripping hand, the Indo-Europeans seem to have been something like the Plains Indians:  sure, they raised cattle rather than living off abundant wild buffalo, but they too were transformed into troublemakers by the advent of the horse. Both still did a bit of farming. They were also alike in that neither of them really knew what they were doing:  neither were the perfected product of thousands of years of horse nomadry.  The Indo-Europeans were the first raiders on horseback, and the Plains Indians had only been at it for a century, without any opportunity to learn state-of-the-art tricks from Eurasian horse nomads.

The biggest difference is that the Indo-Europeans won, while the Plains Indians were corralled into crappy reservations.

It turns out that all those Amerindians shared a fair amount of ancestry with the original Indo-Europeans (ANE, Sibermen), but that’s probably part of some cosmic joke for which we are the punchline.

 

 

Posted in Amerindians, European Prehistory, Indo-European | 100 Comments

The Evil Dead

Someone asked me to go over a chapter he wrote, about the impact of certain customs on human health. One of them was the health advantages of quick burial: the problem is, usually there aren’t any.   People seem to think that the organisms causing decomposition are pathogenic, but they’re not.  People killed by trauma (earthquakes,  floods, bullets) are dead enough, but not a threat.  Sometimes, the body of someone that died of an infectious disease is contagious – smallpox scabs have been known to remain infectious for a long, long time – but most causative agents are unable to survive for long after the host’s death. Now if you’re dissecting someone,  especially if they’re fresh, you probably don’t want to nick yourself with the scalpel – but if you just walk past the corpse and refrain from playing with it, you’re usually OK.

In the past, it may have been a good idea to bury people quickly, so as not to encourage a taste for human flesh in local predators, but that’s a somewhat indirect risk

Someone asked Lewis Thomas about the health risks of unburied bodies, with the intent of using a public-health threat as a legitimate reason to break the undertaker’s strike in New York – but the threat just wasn’t there. He said so, being an imperfectly political person.

 

Posted in Evolutionary Medicine | Tagged | 69 Comments

Remix

There is a new paper out in Science that analyzes the genome of a man (K14) that lived and died about 37,000 years ago, in Russia. They found that this individual came from a population that had shared ancestry with A.  Basal Eurasians, that mysterious population, sister to the main Out-of-Africa expansion and B. a population ancestral to both western hunter gatherers (WHG) and Ancient North Eurasians ( ANE, Sibermen).  In other words, a mix something like modern Europeans, but long, long ago.

Willerslev concludes that there was widespread intermingling back in the stone age: Western Asia was a metapopulation with repeated, possibly continuous gene flow, instead of a few discrete migration events.

The problem is that none of the other evidence agrees with this theory.  We’ve looked at the DNA of Mesolithic hunter-gatherers in Western hunter-gatherers – funny, they don’t have any Basal Eurasian mixture, or any ANE, either.  The Neolithic farmers of Europe have Basal Eurasian, but they don’t have any ANE, and although they have a component that is similar to the WHG, their uniparental lineages have almost no overlap with those of the western hunter-gatherers.  The 24,000-year-old Mal’ta skeleton  from Siberia is a good fit to ANE, but has no Basal Eurasian admixture. Moreover,  the Mesolithic and Neolithic samples are ~20,000 years later than K14.  If they were contemporaneous with K14, you could maybe argue that gene flow was common but just hadn’t reached them yet.  But they weren’t, and you can’t.

The thing is , you can mix two populations with distinct drift histories, and later detect the admixture event and say something about the original populations  – but you can’t unmix them – at least not by natural selection or drift, the only available processes in nature.

So Willerslev’s conclusion is wrong.  Moreover, we have plenty of evidence of serious migrations in Europe ( and elsewhere):  over time, the EEF expand and the Mesolithic hunters shrink. Later, all the villages in the Balkans are burned down, and all the houses in Germany and Poland disappear: sure looks as if someone came knocking.

What then is the real story?  Well, I see two possible explanations.  One is that there was was a small mixing event that produced a population with all three components – a population that wasn’t a major source of ancestry for later  populations. In the same way, if the daughter of a European Mesolithic hunter and a Basal Eurasian had married the son of an Ancient North Eurasian dude and a proto-Chinese chick in 10,000 BC, , they would have produced the world’s first Mexican, even if this complicated love-story happened thousands of years before Columbus. Still, one synthetic Mexican wouldn’t have mattered much – and it wouldn’t have meant that real, live Mexicans were descended from that early synthetic Mexican.  For that matter, although most of the people in Chile and Mexico are a mix of European and Amerindian, those two populations originated in separate admixture events.

The other possible explanation is error: they’ve made a mistake.  The genome quality is not all that good (2.42 X), and the fraction of genome recovered is not large – this might have made things more difficult.

Posted in Amerindians, European Prehistory, Indo-European | Tagged | 68 Comments

Horsepower

300px-Comanche_Feats_of_Horsemanship

The Comanche used to raid into Mexico. In the fall, small groups joined up and rode south on a network of trails, called the Comanche Trace. Some came from as far away as the Arkansas River. In places, there was a beaten path as much as a mile wide. They often rode at night, when the moon was full. Some allied tribes, like the Kiowa and Kiowa-Apache, accompanied them. Each warrior took three or four horses with him.

The Comanche raided as far as Jalisco.  The Kiowa-Apache, who were the most daring, once came back with parrots.  Mostly, though, they stole cattle and horses – tens of thousands of them –  and kidnapped people.

Unless stopped by a real army, the Comanches could and did push back the frontier of settlement. “The Legislature of Chihuahua described the situation it faced in 1846. “We travel the roads…at their [i.e. the Comanches and Apaches] whim; we cultivate the land where they wish and in the amount they wish; we use sparingly things they have left to us until the moment that it strikes their appetite to take them for themselves.” Traveler Josiah Gregg said that “the whole country from New Mexico to the borders of Durango is almost entirely depopulated. “

During the Civil War, when the US Cavalry and Texas Rangers were otherwise occupied, the Comanche pushed back the frontier in Texas by 100 kilometers or so.

These guys didn’t have to fight from horseback, although they could and did. if 50 raiders showed up suddenly at a small village, the local farmers were screwed, unless of course  they had Yul Brynner, Charles Bronson, and Steve McQueen around.

The Comanche generally inflicted far more casualties than they suffered: in the winter of 1845-1846, 652 Mexicans and 48 Comanches were killed. At that, the Comanche lost more than they had t0 – they took extreme risks to recover the bodies of fallen warriors.  And sometimes they seemed to seek out a fight rather than just raid – presumably in search of  ‘undying fame’.

If the Yamnaya Indo-Europeans could ride, they could have inflicted similar havoc on Old Europe.  They didn’t need dramatically better weaponry: mobility makes it work. Without a state and army, how could Old Europe have stopped it?

I wonder if multispectral satellite imagery could find signs of something like that Comanche trace coming out of the Ukraine.

Posted in Amerindians, European Prehistory, Indo-European | Tagged | 104 Comments

The Inexorable Progress of Science: Archaeology

In 1939, archeologists and prehistorians seem to have thought that agriculture was brought to Europe by a gracile Mediterranean people, and was in large part spread by their expansion.  They thought that the Corded Ware culture was Indo-European and probably originated in South Russia. Here’s an example, from Carleton Coon’s The Races of Europe (1939):

“We shall see, in our survey of prehistoric European racial movements, 8 that the Danubian agriculturalists of the Early Neolithic brought a food producing economy into central Europe from the East. They perpetuated in the new European setting a physical type which was later supplanted in their original home. Several centuries later the Corded people, in the same way, came from southern Russia (i.e.Ukraine) “

“There has been much discussion over the origin of the Corded people, and many cradle areas have been proposed. Childe, despite several objections which he himself raises, prefers to derive them from southern Russia , where the typical cultural elements of the Corded people are found mixed with other factors. The so-called boat-axe, the typical battleaxe form which they used, has relatives all the way to the Caucasus and beyond. And the horse, their use of which in the domestic form is not fully confirmed, since the grave examples might conceivably have been wild ones, was first tamed in Asia or in southern Russia.”

A lot of this stems from  Gordon Childe’s work – for example The Aryans, published in 1926.  Understand that this was all before carbon dating, and before a tremendous amount of modern archaeological work, including much of the work in the Balkans.

Archaeology took a different path in the 1960s and later. Archaeologists became very uncomfortable with the idea of migration, colonization, conquest, and prehistoric violence. I say this without really understanding its inner nature: I personally am made quite uncomfortable by the thought of dinosaur-killing asteroids or Yellowstone-scale megavolcanoes showing up in my neighborhood, but that doesn’t stop me from thinking that they occurred.  I don’t get it.

The low point in acceptance of the reality of prehistoric violence seems to have occurred in the 1970s, according to Lawrence Keeley (War before Civilization).  In those days, a log palisade with a 9-foot-deep ditch surrounding a frontier Neolithic village was explained as expressing the “symbolism of exclusion.”

Theories that disallowed migration (let alone conquest) became more and more popular with time.  I can find examples of grown human beings suggesting that the Anglo-Saxonization of England need not have required any actual Anglo-Saxon immigrants at all.  Grahame Clark didn’t rule out all migrations, but he and his immediate followers were definitely against the idea of a “vast Kulturkreise covering large portions of the Continent which gave rise to entirely hypothetical‘ethnic groups’ such as the Kurgans and the Beaker People, often identified, on the flimsiest of grounds, with the large ethno-linguistic groups observable a millennium or more later such as the Hellenes or the Celts.”

Pots not people rules OK!

Colin Renfrew seems to have been motivated in part by an aversion to migrationism.  That’s too bad.  I had thought (not knowing much about it) that he was primarily motivated by a realization that agriculture is often spread by a demographic expansion, a most powerful mechanism. And in fact his model would have been perfectly correct for Europe around 4000 BC.  But to the extent that he subscribes to the ideological prejudice against population movements, he’s a loon. I understand that an article in British Archaeology claimed that this prejudice had gotten to the point where some graduate student “would soon come up with a paper ‘proving’ that the first humans in Britain weren’t immigrants at all, but purely indigenous, symbolically transformed reindeer.”

The Indo-European linguists seem to have been immune to this nonsense.  All honor to them – although they really should start making use of the flood of new genetic results. The archaeologists behind the Iron Curtain also successfully resisted this crap – but then, they were pretty far from Harvard!

I was noting something from Mario Alinei (an advocate of a model in which nobody ever invaded Europe, probably including Omaha Beach).  He blames ideology:

” Surprisingly, although the archaeological research of the last few decennnia has
provided more and more evidence that no large-scale invasion took place in
Europe in the Calcholithic, Indoeuropean linguistics has stubbornly held to its
strong invasionist assumption, and has continued to produce more and more
variations on the old theme.

Clearly, the answer is ideological. For the invasion model was first advanced in the nineteenth century, when archaeology and related sciences were dominated by the ideology of colonialism, as recent historical research has shown. The successive generations of linguists and archaeologists have been strongly inspired by the racist views that stemmed out of colonialism. Historians of archaeology (e.g. Daniel 1962, Trigger 1989) have repeatedly shown the importance of ideology in shaping archaeological theories as well as theories of human origins, while, unfortunately, linguistics has not followed the same course, and thus strongly believes in its own innocence.”

You know, he may have a point.

With a very limited set of clues, smart guys managed to get key facts about European prehistory roughly correct almost 90 years ago . With tremendously better tools, better methods, vastly more money, more data, etc, archaeologists (most of them) drifted farther and farther from the truth.

Posted in European Prehistory, Indo-European, Linguistics | Tagged | 125 Comments