The Poop Gap

There’s a new article out in Science tracing the splits in gut flora. It looks as if the gut bacteria in chimpanzees split with those in humans 5.3 million years: doesn’t quite match our genetic estimates based on Human/chimp autosomal DNA differences, but it’s in the ball park. They estimate the human-gorilla split at 15.6 million year ago, but that can’t be right: we know that gorillas split off just a bit before the human-chimp split. Perhaps gorilla diet changed drastically, and maybe they picked up new bacteria from some other species.

Different populations of modern humans apparently have pretty different microbiomes. The gut bacteria from people in Malawi appear to have diverged 1.7 million years ago from those in Europeans (people from Connecticut). That is surely too old to be a consequence of modern humans’ trek out of Africa: it looks as if AMH, after leaving Africa, picked up gut flora from archaic sapiens like Neanderthals and Denisovans and dwarves.

Microbiomes are trendy. We know that fecal transplants can cure C difficile (pseudomembranous colitis) lickety-split: they might help with Crohn’s disease and ulcerative colitis. Some researchers think the microbiome has something to do with the initiation of multiple sclerosis. Others suspect that it may play a role regulating how people think and feel – in particular, mood disorders. Autism has been mentioned.

So.. Poop matters: it certainly can affect health, and it may influence brain function. People from sub-Saharan have divergent poop, or you could say that Eurasians do. Are there differences in brain function between sub-Saharan Africans and Eurasians? Sure: Africans do poorly on IQ tests and in academic subjects. They have significant higher rates of schizophrenia, higher murder rates, etc.

Maybe it’s the poop. It’s worth checking out. Perhaps the fault lies not in our stars, or our genes, but in our stool.

Already, eager experimenters – paleos on stilts – are trying to dramatically modulate their internal flora.

“AS THE SUN set over Lake Eyasi in Tanzania, nearly thirty minutes had passed since I had inserted a turkey baster into my bum and injected the feces of a Hadza man – a member of one of the last remaining hunter-gatherers tribes in the world – into the nether regions of my distal colon. I struggled to keep my legs in the air with my toes pointing towards what I thought was the faint outline of the Southern Cross rising in the evening sky. With my hands under my hips – and butt perched against a large rock for support – I peddled an imaginary upside down bicycle in the air to pass the time as I struggled to make sure my new gut ecosystem stayed put inside me.”

The problem, he’s likely running this in the wrong direction, unless he’s just gotten a high-paying job as a professional hunter-gatherer. Generally, we want to better adapt people to key features of industrial civilization, like eating Chicago-style pizza while doing calculus homework, rather than shooting pizened arrows at gazelles.

Judging from Common Core, the standard approach with a potentially gap-closing panacea is to impose it on the entire country without running any careful, small-scale tests. Fortunately, due to Sturgeon’s Law, we don’t ever have to worry about running out of raw material.

Now, I know what you’re thinking. There’s a potential show-stopper

The question is – are blacks in the mood to take any more shit from the Man?

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Still Italian

In the early days of the empire, Rome was big, probably around 1 million. There were some number of Jews (thousands at least, perhaps as many as 40,000 by some estimates, although that’s probably high). There were also other foreigners in Rome – probably mostly Greeks, but also some Gauls and Syrians and such. There were also many slaves in Italy, perhaps a third of the population.

Mostly those slaves were from Europe, obtained in wars of expansion: Gaul, Hispania, Germany, Britannia, Greece, etc. Wiki suggests that their European origins is why they didn’t have much affect on Italian genetics because they were European, but that’s wrong. You can certainly detect genetic differences between Gauls and Italian, Germans and Italians, etc. Wiki is correct in saying that you don’t see much sign of this ancient immigration in Italian genetics, but it’s not because they were just like Italians: it has to be because they died out.

The cities were population sinks, and collapsed with the Empire. I doubt if slaves had high birth rates: certainly those working in mines or quarries didn’t. Nor did gladiators. One way or another, the foreigners in Italy, the vast majority of them, disappeared.

Now you see some signs of other stuff in Sicily or Calabria today, but that seems to be later, from Arab or Byzantine times.

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Even more on Ashkenazi ancestry

There’s yet another paper out on Ashkenazi ancestry. It’s clear that this problem is a bit tricky, because the ancestral groups are not as different as one would like – this makes distinguishing the origins of chromosomal segments more difficult. Drift doesn’t help. So they check out and calibrate various algorithms with simulated scenarios, which makes sense.

Here they’re looking at finer details. When they analyze the origins of the European component of Ashkenazi ancestry, they conclude that most is southern – probably Italian, but that smaller amounts originated from (probably) Western Europe and (more certainly) Eastern Europe: and in that temporal order. They conclude that the Italian admixture slightly predated a late medieval founder event. Different methods came up with somewhat different estimates for the total amount of European ancestry: the local ancestry inference (LAI) approach came up with 53% European, while the GLOBETROTTER analysis came up with an estimate of 67% European ancestry (after calibration by simulations). In their best guess, they split the difference and go for 60% European.

To sum up, their model is that a population from the Levant mixed with Italians, and shortly thereafter moved to the Rhineland (the founding bottleneck), perhaps mixing to some degree with the local Europeans there, and certainly mixing some with Slavic types when they moved to the Polish-Lithuanian Commonwealth.

How do their conclusions differ from those in the last report? Previously they were thinking that the bottleneck was around 1350, a product of the Black Death and savage persecution – now they’re talking the original settlement in the Rhineland. Previously they had a somewhat lower estimate of European ancestry (~48%, now 60%). I thought these two conclusions likely a couple of years ago.

The big new point, important if correct, is that the admixture with Italians is relatively recent – too recent to have happened back in Roman times. In their model, this main admixture event is 25-55 generations ago, while the founding bottleneck is 25-35 generations ago. It’s not impossible that the admixture happened at the same time as the founding. This I didn’t expect.

How to improve our understanding? aDNA – dig we must!

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Between the lines

Sometimes when reading a piece in a paper or magazine, I get the impression that the reporter is not necessarily 100% on board with the official editorial position, particularly when it is ripely insane, as is so often the case nowadays. I figure that there must have been many examples of this in the East Block, back in the day: although you were dicing with death if you tried it with Stalin. I wondered about this after reading a bit by Farhad Manjoo, about Peter Thiel, in the New York Times:

“Though Silicon Valley has well-known problems with diversity in its work force, people here pride themselves on a kind of militant open-mindedness. It is the kind of place that will severely punish any deviations from accepted schools of thought — see how Brendan Eich, the former chief executive of Mozilla, was run out of his job after it became public that he had donated to a campaign opposed to gay marriage.”

You could almost suspect that Manjoo was teetering on the edge of crimethink.

Stalin, by the way, didn’t have this kind of worry: he was free to say that that Pavlik Morozov was ‘a rotten little shit, ratting on his parents like that.’

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Building momentum

Recent work indicates that there were high levels of genetic differentiation between the early farmers in the Levant, Anatolia, and western Iran. What this means that is that before the Holocene, they didn’t mix very much – probably less than one immigrant per generation. This seems to have been a general tendency in Eurasia – possibly in Africa as well, but we don’t have as much ancient DNA information out of sub-Saharan Africa yet.

On the other hand, we also see populations replacing other populations, over and over – and sometimes that resulted in admixture. Eurasians picked up a bit of Neanderthal ancestry when they expanded out of Africa. Altai Neanderthals picked up some AMH ancestry, possibly when their ancestors expanded back into the Middle East. Melanesians picked up some Denisovan ancestry.

If population A rolled over population B and occupied their territory, there was often a few percent of admixture – certainly enough to transmit key favorable alleles. But as neighbors, very little gene flow. So when people say that a little gene flow is likely to be the explanation of that vaguely Andamanese trace in Brazil, I kinda doubt it: replacement with a little admixture is known to have happened back in those days, but peaceful amalgamation had to have been rare, in order for genetic differentiation to remain high.

Of course the causes of this genetic isolationism matter. To some extent they must have been geographical barriers, particularly around the last glacial maximum. If such barriers were the only cause, then any relaxation or breach would have resulted in enough admixture to rapidly decrease genetic differentiation. On the other hand, isolation probably bred isolation: populations that had very low gene flow for long periods of time surely had very divergent languages and customs. And modern humans can effectively fission into groups that can act, sometime, almost like different species – low gene flow, even though there are no fertility barriers. Linguistic fission may go back a long time and help explain the long-term low effective population size – but we don’t know.

When people started farming, at first they were not biologically different from their immediate hunter-gatherer ancestors. Eventually they would be different: better adapted to the new diet, the increased crowding, the psychological demands of a very different way of life – but that took at least some time. After they were adapted to farming, the tendency towards farmers expanding, rather than the idea of farming being transmitted, would increase: the biological edge shows up. But at first, before much adaptation, idea transmission might have more competitive with demography. I throw this out as a possible partial explanation of the pattern we are seeing: first the idea of farming spreading through core populations in the Middle East (possibly combined with independent invention or stimulus diffusion), while a little later those core populations themselves begin spreading outward. In fact, on the ball really got rolling, those populations should have been adapting to expansion itself, just like cane toads.

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Our Dumb World


As far as average IQ scores go, this is what the world looks like. But there are two relevant tests: the Stanford-Binet, and life itself. If a country scored low on IQ but at the same time led the world in Cavorite production, or cured cancer, or built spindizzies, we would say “screw Stanford-Binet”, and we would be right to do so.

Does that happen? Are there countries with low average scores that tear up the technological track? Mostly not – generally, fairly high average IQ seems to be a prerequisite for creativity in science and mathematics. Necessary, although not sufficient: bad choices (Communism), having the world kick you in the crotch (Mongols), or toxic intellectual fads can all make smart peoples unproductive.

The exceptions, such as they are, seem to be a result of strong population substructure. India has a low average IQ, but there are distinct subpopulations (castes) that apparently have much higher IQ – although I’d love to see some decent studies on this. With numbers.

A population with a low average has drastically fewer people that exceed a high threshold – should, anyhow, if the distribution is much like a gaussian. This means that most of the world with average scores well below 100 produces very few sharp cookies, and thus I wouldn’t expect them to do much in the way of scientific and technical innovation. Nor do they.

So when you hear about even a few people with impressive intellectual accomplishments from a country whose average IQ is not very high, you suspect population substructure. Which is why I suspect that there is significant population substructure in Iran. But maybe there’s something else going on?

Of course classes are an example of substructure: higher socioeconomic groups usually have higher average scores, and most of that difference is probably genetic. If recruiting and retaining people into the upper classes goes up with IQ, then the upper classes will be smarter – some, anyhow. It’s not inevitable – certainly isn’t true in the UAE.

So as a population evolves from egalitarian tribesmen to a more hierarchical society, you may see a higher fraction of people with IQ above high threshold X, X being what you need to make progress on Diophantine equations, or write the Popol Vuh, or whatever. Even if the average IQ of the population as a whole does not change. In the same way, if someone comes in and chases off your upper classes to France, or simply kills everyone living in a city, that fraction is going to go down. Decapitation. Moreover, those fewer smart cookies left are probably less likely to meet and cooperate.

You could improve the situation, raise the average, by selection for IQ. But that takes a long time, and I know of no case where it was done on purpose. You could decrease inbreeding, for example by banning cousin marriage. That only takes one generation. You could make environmental improvements, iodine supplementation being the best understood. People assume that there are a lot of other important environmental variables, but I sure don’t know what they are. In practice the rank ordering of populations seem to be the same everywhere, which is not what you would expect if there were strong, malleable environmental influences.

Let me expand a little on that.  Diasporas track. The populations that scored low at home score low in new lands: those that scored high continue to score high.  Chinese that entered Malaysia as illiterate tin miners end up doing well in a few generations: Japanese that moved to Brazil to pick coffee are high achievers now.

Is it easy to notice such differences? Well, for ordinary people, it’s real easy. Herero would ask Henry why Europeans were so smart – he said he didn’t know. But with the right education, it apparently becomes impossible to see. Few anthropologists know that such differences exist and even fewer admit it. I’m sure that most have never even read any psychometrics – more importantly, they ignore their lying eyes. Economists generally reject such explanations, which is one reason that they find most of the Third World impossible to understand. I must give credit to Garret Jones, who is actually aware of this general pattern. Sure, he stepped on the dick of his own argument there at the end of his book, but he was probably lying, because he had to. Sociologists? It is to laugh.

Generally, you could say that the major job of social science is making sure that people do not know this map. Not knowing has its attractions: practically every headline is a surprise. The world must seem ever fresh and new to the dis-illuminati – something like being Henry Molaison, who had his hippocampus removed by a playful neurosurgeon and afterwards could not create new explicit memories.

So when we tried a new intervention aimed at eliminating the GAP, and it failed, Molaison was surprised, even if 47 similar programs had already failed. Neurologically, he was much like a professor of education.

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Economists and the Reds


It seems to me that Western economists didn’t do very well in understanding the Soviet economy, or that of other East Bloc countries. According to Paul Krugman, “typical estimates of the GDP of East Germany before the old regime collapsed put its real GDP per capita at 70 or 80 percent of the West German level – meaning that East Germany was actually richer than some regions in the West. Yet after the fall of the Berlin Wall, visiting Westerners found something that looked like a Third World economy, with antiquated factories (and disastrous environmental problems) producing consumer goods of ludicrously low quality (like the notorious East German Trabant, an automobile that makes a Honda or Ford seem like a Mercedes). We used to think that the Soviet Union had an economy about half as large as America’s, that is, bigger than Japan’s; nowadays Russia seems to have less economic power than, say, Italy. ”

I know someone who, as late as 1985, came away from postgraduate work at Cornell convinced that East Germany was more productive and prosperous than West Germany. Someone in Army Intelligence!

By “we”, Kreugman is talking about academic economists in the US and western world generally. Paul Samuelson said, in his standard textbook, ““the Soviet economy is proof that, contrary to what many skeptics had earlier believed, a socialist command economy can function and even thrive.” But it wasn’t just him.

While we’re at it, I’m not sure that that people like Hayek or von Mises or Friedman ever had much coherent to say about the performance of the Soviet economy in 1942.

But I am an observer, an outsider. I would welcome thoughts from readers who are professional economists, have talked with them and hung out with them, gotten stinking drunk with them and woken up naked under a shower in the girls’ dorm, etc.

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