Here we successfully sequenced 67 complete mitochondrial DNA genomes of 5200 to 300-year-old humans from the plateau. Apart from identifying two ancient plateau lineages (haplogroups D4j1b and M9a1a1c1b1a) that suggest some ancestors of Tibetans came from low-altitude areas 4750 to 2775 years ago and that some were involved in an expansion of people moving between high-altitude areas 2125 to 1100 years ago, we found limited evidence of recent matrilineal continuity on the plateau.
Congratulations to the authors. I enjoyed this paper and hope they have more in the works.
Skipping past some of the technical discussion, let’s get down to the nitty-gritty of what it all means:
The haplogroup networks and haplotype–haplogroup sharing demonstrated to us that there was partial matrilineal continuity in Tibetans from 5200 years ago.
That means modern-day Tibetans descended from a mix of peoples, some of whom have been there for over 5,000 years, and some of whom arrived recently.
Under this continuity, some people spread from low-to-high altitudes 4750 to 2775 years ago and some expanded within high-altitude areas 2125 years ago. The timing revolved around the high-altitude agriculture transformed by barley, which appeared 5.2 ka near the northeastern edge of the plateau and moved into high altitudes by 3.6 ka .
Farmers. I wonder how difficult it was to get barley to grow up there. Tibet seems like a pretty harsh environment.
However, based on the 16 haplogroups that have a frequency in Tibetans (a subset of 21 unique haplogroups), D4j1b and M9a1a1c1b1a would represent about 13% (2 out of 6) as the footprint of that event. Thus, our findings did not favour a substantial migration of lowland farmers to the high-altitude areas.
So, farmers did expand into Tibet, but not a ton of farmers (or at least, not a ton of farming women.) Probably because Tibet is a really harsh place–both for people and barley strains that aren’t adapted to living there.
An explanation for the surplus of unaccounted maternal lineages could be that there were earlier waves of populations who settled into higher altitudes and underwent isolation by distance . The earlier settlers were potentially hunters and gatherers who left behind no human fossils, perhaps connected to the blade tool assemblages or fossilized handprints and footprints dating to as far back as 40–30 ka  or 13–7 ka . Our results could support a recent diffusion of plateau populations into an otherwise stable population continuous with previous high-altitude populations. A similar point of view has been made from analysing the whole genomes of present-day Tibetans .
What would being a hunter gatherer in Tibet have been like?
I figured there was probably some ancient population that has contributed to the modern Tibetan population both because of the aforementioned environmental difficulties, and also because the Tibetans show adaptations to the area, which take time to accumulate. Among those adaptations, Tibetans have some DNA they appear to have picked up from the Denisovans, and Denisovans probably haven’t lived in Tibet in a very, very long time.
All of the mtDNA and Y chromosome haplogroups we observe at Shum Laka are associated today with sub-Saharan Africans. The two earlier individuals carry mtDNA haplogroup L0a (specifically L0a2a1), which is widespread in Africa, and the two later individuals carry L1c (specifically L1c2a1b), which is found among both farmers and hunter-gatherers in Central and West Africa. Individuals 2/SE I and 4/A have Y chromosomes from macrohaplogroup B (often found today in hunter-gatherers from Central Africa17), and 2/SE II has the rare Y chromosome haplogroup A00, which was discovered in 2013 and is present at appreciable frequencies only in Cameroon—in particular, among the Mbo and Bangwa in the western part of the country. A00 is the oldest known branch of the modern human Y chromosome tree, with a split time of about 300,000–200,000 bp from all other known lineages.
At 1,666 positions… that differ between present-day A0018 and all other Y chromosomes, the sequence of the Shum Laka individual carries the nonreference allele at a total of 1,521, translating to a within-A00 split at about 37,000–25,000 bp.
As noted last week, there’s a lot of genetic diversity in Aka/Baka pygmies back around 20,000 years ago.
In other news, National Geographic has an interesting article on a Biblical enemy.
Modern archaeologists agree that the Philistines were different from their neighbors: Their arrival on the eastern shores of the Mediterranean in the early 12th century B.C. is marked by pottery with close parallels to the ancient Greek world, the use of an Aegean—instead of a Semitic—script, and the consumption of pork.
The “sea peoples” were a bunch of invaders who, like the Vikings, showed up suddenly in the coastal Mediterranean in the midst of the Bronze Age Collapse (indeed, they triggered much of it.)
The four early Iron Age DNA samples, all from infants buried beneath the floors of Philistine houses, include proportionally more “additional European ancestry” in their genetic signatures (roughly 14%) than in the pre-Philistine Bronze Age samples (2% to 9%), according to the researchers. While the origins of this additional “European ancestry” are not conclusive, the most plausible models point to Greece, Crete, Sardinia, and the Iberian peninsula.
Why were Philistines burying babies underneath their houses? (Answer: to keep the family together. Apparently a common practice to save the bones of your dearly departed.)
Interestingly, the “European” component in these burials is a blip-in-time, but the culture remained long after. When we put together the DNA, archaeology, and various written records from the various Mediterranean cultures, we can piece together a pretty coherent picture.
I remember reading back in highschool–I still have the book; it’s in the other room–about how the Trojan War was a real event, but that the ancient Greek narratives described a conflict that was actually geographically much bigger than what Homer described. During the Greek dark age caused by the Bronze Age Collapse, there were many oral poets and many stories composed about the deeds of the late heroes, and the ones that have made it down to represent only a small selection of these. Of the ones we have, people tend only to read the most famous and complete, but even here we can find differences in the narrative account between, say, Homer and the tragedians, who were all working from the same base material of popular oral poetry.
In one of the lesser-known accounts, the Greeks, having lost Helen to Paris, go through all of the effort of rounding up all of the heroes, making all of the requisite sacrifices to he gods, etc, set sail, and burn down some city in Egypt. They return home and realize, oopsies, we burned the wrong city and have to go do it all over again, this time at Troy.
Another story holds that Helen herself was never in Troy, but spent the war hanging out in peace and prosperity in Egypt while the Trojans themselves suffered.
Troy being, as far as I know, a rather small and unimportant city by the standards of the day, I have thus long believed that the “real” Trojan war was a conflict between Greek tribes and the Egyptians, who had a civilization worth looting, and that they happened to burn/loot a lot of other small towns along the way. We hear about Troy and not Egypt because the Greeks conquered Troy and got their butts kicked in Egypt, and no one likes to sing about their losses.
This whole business of the Greeks going a-Viking collapsed the local Mediterranean economy, but of course there was a lot of other stuff going on at the same time, too. Bronze Age Collapse can’t just be blamed on the Greeks. Not only were there non-Greek invaders in other places, there were also a bunch of crop failures, droughts, etc. The effects were big:
Interestingly, though, the pull-back of some of the bigger empires at the time, like the Egyptians, may have let some of the smaller players, like the Israelites, thrive. King David, if the accounts can be believed, got his start fighting Philistines. The reign of King David and his son, Solomon, can be basically taken as the high point of Israelite wealth and power, and notably while literacy was destroyed nearly everywhere else, it persisted in the Biblical lands (which is probably why we have the Old Testament at all).
As both the Biblical, Egyptian, Greek, and DNA accounts agree, the Philistines were mostly male invaders. They therefore married local women, and over the centuries either left, died, or got mixed into the local genetic milieu.
A paper has just been released on the first ancient DNA recovered from central African burials: Ancient West African Foragers in the Context of African Population History, by Lipson, Ribot, Reich, et al. This is exciting news because our ancient genetic coverage of central Africa has been, until now, completely nonexistent. The local climate tends to degrade human remains quickly, making it difficult to recover DNA, and most genetics researchers don’t live in Africa.
Researchers have recovered the remains of four people, two from about 8,000 years ago and two from 3,000 years ago, buried in Shum Laka, Cameroon. (Cameroon is the country right in the big turn in the curve of Africa’s coast; Shum Laka has been inhabited by humans for about 30,000 years.) The really interesting part is the “ghost population,” which we’ll get to soon.
The burials turned out to be Pygmy people, not Bantus, despite the belief among linguists that Cameroon is the Bantu homeland. From the paper:
One individual carried the deeply divergent Y chromosome haplogroup A00, which today is found almost exclusively in the same region12,13. However, the genome-wide ancestry profiles of all four individuals are most similar to those of present-day hunter-gatherers from western Central Africa, which implies that populations in western Cameroon today—as well as speakers of Bantu languages from across the continent—are not descended substantially from the population represented by these four people. We infer an Africa-wide phylogeny that features widespread admixture and three prominent radiations, including one that gave rise to at least four major lineages deep in the history of modern humans.
The Bantu language group is a branch of the larger Niger-Congo language family, one of the biggest (along with Indo-European and Sino-Tibetan) language families in the world. Niger-Congo contains about 1,740 languages (depending on how you count) with 700 million speakers. The Bantu branch accounts for half of them, or 350 million people.
The Bantu branch has clearly undergone a massive expansion over the past 3,000 years. 4,000 years ago, central Africa belonged to the Pygmies, Bushmen, and their relations. Today, those populations are tattered remnants of their former empires; the Bantus are dominant. The Bantu expansion is thus one of the great conquering events of recent history, comparable to the Indo-European expansion. The size of the Pygmy and Bushman population has consequently collapsed, though at what speed, we don’t know.
The presence of a significant Pygmy population in the supposed Bantu homeland back when the Bantu speakers were gearing up to conquer a huge chunk of the Earth’s surface indicates that Cameroon might not actually be the Bantu homeland. Of course there are easy fixes to this theory, like “the region just to the west of Cameroon is the Bantu homeland” or “there are still Pygmies in Cameroon today; researchers just happened to find some Pygmies,” but I propose a different possibility: the Bantu homeland is in the Sahara.
Yes, the Sahara is an enormous desert–today. Before 3,500 BC, the Sahara was significantly wetter. The Niger-Congo speakers started as agriculturalists who farm along the edge of the Sahara. During the African Humid Period, 3,500 years ago and before, much of the Sahara was green, full of plants and animals, flowing rivers and giant lakes. I propose that the Bantu homeland was in the vicinity of lake “Megachad,” which aside from having a great name, was an enormous lake in central Chad, overlapping the borders of Nigeria, Cameroon, and Niger, fed by a suitably extensive network of tributaries. Today, only remnants of the lake remain.
The drying of the Sahara and Lake Megachad turned the Bantu’s homeland to dust; just based on the African topography and modern rivers, they probably headed into northern Cameroon, eastern Nigeria, and the Central African Republic. The area of Cameroon where these pygmy skeletons have been found looks a little harder to get to, cut off from the north/east by highlands. This area may have therefore been a bit of a refugia during the Bantu expansion.
I think it is common for people to think of African populations as relatively homogeneous because it is the origin point from which humanity spread to Asia, Europe, Australia, the Americas, etc. But Africa isn’t a point. It’s big, and people spread out and wandered around Africa for thousands of years before some of them headed north.
The oldest extant human splits aren’t between Africans and non-Africans, but between Pygmies/Bushmen and everyone else. This split happened around 250,000 years ago. This was followed by more splits within Africa, like the one between West and East Africans about 150,000 years ago, and the out-of-Africa event about 70,000 years ago. Here’s a mostly-accurate tree diagram, Bushmen and Pygmies on the right:
(The big inaccuracy in this diagram is the yellow line representing Eurasian back-migration leaving genetic traces in modern Bushmen/Khoisan peoples. That never happened; the results turned out to be a computer error.)
Before the Bantu expansion, Pygmies and Bushmen were among the biggest ethnic groups on the planet. The extremely high Baka Pygmy population on this graph is probably partially due to high genetic diversity due to the merger of multiple long-separated groups rather than a massive Pygmy boom and then genocide, but I think it is still fair to conclude that relatives of today’s Pygmies and Bushmen once controlled most of central and southern Africa.
(Today, the biggest ethnic group is the Han Chinese.)
From the Science article:
In the new study, geneticists and archaeologists took samples from the DNA-rich inner ear bones of the four children, who were buried 3000 and 8000 years ago at the famous archaeological site of Shum Laka. The researchers were able to sequence high-quality full genomes from two of the children and partial genomes from the other two. Comparing the sequences to those of living Africans, they found that the four children were distant cousins, and that all had inherited about one-third of their DNA from ancestors most closely related to the hunter-gatherers of western Central Africa. Another two-thirds of children’s DNA came from an ancient “basal” source in West Africa, including some from a “long lost ghost population of modern humans that we didn’t know about before,” says population geneticist David Reich of Harvard University, leader of the study.
I spent a while trying to figure out what this is saying, because it isn’t clear. First, I doubt they found that the 8,000 year olds were cousins to the 3,000 year olds. The notes in the extended data section of the paper claim to have found a nephew/aunt or niece/uncle relationship between two of the children; the other two were less closely related–possibly cousins.
This doesn’t tell us which skeletons they got the DNA from, but it turns out that one of the good ones was 8,000 years old.
The article claims that 1/3 of their DNA came from ancestors related to the [Aka] Pygmies and 2/3s from “basal West Africans”, who are also closely related to the modern Bantus.
This is confusing because it makes it sound like these children were a cross between Aka Pygmies and Bantus, and that the’re 2/3s Bantu, in which case they’d be more Bantu than Pygmy and this really wouldn’t upset the idea of Bantus in Cameroon.
The thing they didn’t say–and I only figured out from looking at theextended data–is that the modern Aka are not 100% “ancestral pygmy.” They are alsopart “basal West African.” (41% pygmy ancestor and 59% BWA, to be exact.) This is actually quite similar to the 1/3 and 2/3s found in the burials in Shum Laka. So there probably was an event where people related to modern Bantus mixed with an ancient Pygmy population, and their descendants include both the modern Aka Pygmies and the Shum Laka children.
The Aka Pygmies now live near the border between Cameroon and the DRC. (The “ba-” suffix, found in names like Bantu, Baka, and Batswana, means “people,” so “Baka” just means “Aka People.” Batswana means “Tswana people;” “bo-” means land, so Botswana is “Land of the Tswana.”)
The Mbuti Pygmies, whom you have probably also heard of, live much further from the Cameroonian border and have less Bantu DNA. The Mbuti Pygmies average only 4’6″, while the Aka Pygmies average a couple more inches. The average Aka man stands about 4’11”; the women a little less. Don’t fall into the trap of thinking that the Aka aren’t “real pygmies”–they’re still very short by modern standards, and as this paper shows, the mixing that created them occurred over eight thousand years ago. The Aka have been a distinct ethnic group for an extremely long time.
People always ask why the Pygmies are so small, but I think this question is backward. Bushmen are also short (compared to Dinka and Norwegians); I think our common human ancestors were only about 5′ tall. The pygmies got a little shorter, yes, but not by much; the rest of us got taller.
Now, the really interesting thing in this paper is the identification of three “ghost” populations.
Using 405 whole-genome sequences from four sub-Saharan African populations, we provide complementary lines of evidence for archaic introgression into these populations. Our analyses of site frequency spectra indicate that these populations derive 2-19% of their genetic ancestry from an archaic population 15 that diverged prior to the split of Neanderthals and modern humans.
That’s a lot of archaic! Since the populations with the highest rates of ghost archaic live in far West Africa, I assume the Ghost Archaic did, too.
Next we have the Ghost Modern, which I regretfully did not realize is different from the Ghost Archaic when I first wrote about it.
Here, we examine 15 African populations covering all major continental linguistic groups, ecosystems, and lifestyles within Africa through analysis of whole-genome sequence data of 21 individuals sequenced at deep coverage. … Regarding archaic gene flow, we test six complex demographic models that consider recent admixture as well as archaic introgression. We identify the fingerprint of an archaic introgression event in the sub-Saharan populations included in the models (~ 4.0% in Khoisan, ~ 4.3% in Mbuti Pygmies, and ~ 5.8% in Mandenka) from an early divergent and currently extinct ghost modern human lineage.
The Ghost Archaics were in the genus Homo, just like Homo erectus, Homo Neanderthalis, but they were not Homo sapiens. The Ghost Moderns were Homo sapiens. They split off from the rest at about the same time the Pygmies, Bushmen, and everyone else went their separate ways.
The Ghost Moderns later contributed to the ancestors of the Niger-Congo people of West Africa and the Mota burial, a 4,000 year old burial from Ethiopia. A branch later split from the Niger-Congo people, creating the “Basal West Africans” and carrying the Ghost Modern DNA (and a bit of the Ghost Archaic) with it. That branch eventually contributed to the Aka Pygmies, including the children found at Shum Laka.
The third ghost population is the Ghost North African.
GNA split from the West Africans well before the Ghost Moderns, shortly after they had split with the East Africans. They appear to be related to the folks buried at Toforalt, Morocco.
I don’t know anything about the Ghost North Africans, but apparently they also contributed to the Shum Laka people. We’ll have to leave that question open for later.
Perhaps it is this infusion of “ghost” DNA into the ancestors of the Aka Pygmies that that accounts for their apparent enormous population size around 20,000 years ago. In this case, their population probably wasn’t actually enormous so much as it had a lot of genetic variation, caused by the merger of several different groups.
All of these Ghost populations used to be full ethnic groups (or species) in their own right, but today they exist only as a trace of DNA in modern people; they no longer exist as a group. These ghost populations were most likely killed off by other human groups or completely absorbed into them. The Ghost Moderns, for example, were probably finished off during the Bantu expansion.
(Let’s remember that all of these numbers are estimates based on the genetic data we have so far, which is not very much. The numbers could change quite a bit as we uncover more information.)
The final interesting thing was the “deeply divergent Y chromosome haplogroup A00,” found in one of the children. The authors did not look into mtDNA (passed down from mothers to children,) but did investigate local Y-chromosome diversity. A00 is estimated to be around 270,000 years old and is relatively common in Cameroon and, as far as I know, nowhere else. (The relevant Wikipedia page unfortunately contains an error, claiming that the Shum Laka children are most closely related to the Mbuti. They are, as the paper actually says, most closely related to the Aka.)
That’s all for now, but here are a few related things if you want to read more:
Some thoughts on the ancient West African forager genomes paper (Nature). The reality is even more complex, as the next tweet will show… pic.twitter.com/mSZUA9zUwz
African Pygmies practicing a mobile hunter-gatherer lifestyle are phenotypically and genetically diverged from other anatomically modern humans, and they likely experienced strong selective pressures due to their unique lifestyle in the Central African rainforest. To identify genomic targets of adaptation, we sequenced the genomes of four Biaka Pygmies from the Central African Republic and jointly analyzed these data with the genome sequences of three Baka Pygmies from Cameroon and nine Yoruba famers. … Our two best-fit models both suggest ancient divergence between the ancestors of the farmers and Pygmies, 90,000 or 150,000 yr ago. We also find that bidirectional asymmetric gene flow is statistically better supported than a single pulse of unidirectional gene flow from farmers to Pygmies, as previously suggested. … We found that genes and gene sets involved in muscle development, bone synthesis, immunity, reproduction, cell signaling and development, and energy metabolism are likely to be targets of positive natural selection in Western African Pygmies or their recent ancestors.
To investigate the demographic history of Pygmy groups, a population approach was applied to the analysis of 205 complete mitochondrial DNA (mtDNA) sequences from ten central African populations. No sharing of maternal lineages was observed between the two Pygmy groups, with haplogroup L1c being characteristic of the Western group but most of Eastern Pygmy lineages falling into subclades of L0a, L2a, and L5. Demographic inferences based on Bayesian coalescent simulations point to an early split among the maternal ancestors of Pygmies and those of Bantu-speaking farmers (∼70,000 years ago [ya]). Evidence for population growth in the ancestors of Bantu-speaking farmers has been observed, starting ∼65,000 ya, well before the diffusion of Bantu languages. Subsequently, the effective population size of the ancestors of Pygmies remained constant over time and ∼27,000 ya, coincident with the Last Glacial Maximum, Eastern and Western Pygmies diverged, with evidence of subsequent migration only among the Western group and the Bantu-speaking farmers. Western Pygmies show signs of a recent bottleneck 4,000–650 ya, coincident with the diffusion of Bantu languages, whereas Eastern Pygmies seem to have experienced a more ancient decrease in population size (20,000–4,000 ya).
Western Pygmies, ie the Mbuti, were killed by the Bantus during the Bantu expansion of the past 3,000 years.
Eastern Pygmies, ie the Aka, probably experienced a genetic diversification event about 20,000 years ago that makes it look like their population was much bigger back then than it is now. Their population probably has dropped over the years, but probably not as precipitously as the data shows.
As I mentioned yesterday, Carl Zimmer’s article in the New York Times on the new ancient DNA paper with its ho-hum title, Ancient DNA from West Africa Adds to Picture of Humans’ Rise, is a model of how to construct articles upside down to bore complacent NYT subscribers with the opening paragraphs before revealing the unsettling details toward the end. Carl doesn’t mention the word “pygmy” until his 18th paragraph and the word “ghost” until the 24th paragraph.
This blog is now 1,000 posts long, which I think calls for a bit of celebration.
I started this blog because I found the idea that evolution–a process normally thought of as turning fins to feet and gills to lungs–could also code for emergent, group-level behavior like the building of termite mounds or nation states fascinating. Could evolution code for other things? Could it give us male and female behavior? Emotions? Political preferences?
Evolution is ultimately a numbers game: if more people who do X have children than people who do Y, then X is likely to become more common than Y–even if we all believe that Y is better than X.
This gets interesting when X is not obviously mediated by genetics–your eye color, sans contacts, is clearly genetic, but the number of years you spend in school is influenced by external factors like whether schools exist in your society. This is where some people get hung up on causation. We don’t need to posit a gene that causes people to get more or less school. Maybe your village has a school because a mountain climber got lost nearby, your village rescued him, and in gratitude, he built you a school, while the village on the other side of the mountain doesn’t have a school because no mountain climber got lost there. Once a school exists, though, it can start having effects, and if those effects are not random, we’ll see genetic correlations.
If people who have more education make more money and end up buying more food and raising more children, then school is exerting a selective effect on society by causing the kids who happened to live near the school to have more children. From an ecological standpoint, the school is operating like a spring in a desert–we get more growth near the spring than far away from it, and whatever traits were common in the village–even ones that have nothing to do with education–will become more numerous in the overall population. If this trend continues, then the cultural habit of “going to school” will continue to proliferate.
We can also posit the opposite case: in the village with the school, kids spend many years at school and end up marrying later and are more educated about things like “birth control” than their neighbors on the other side of the mountain. The kids on the other side of the mountain marry younger and have a bunch of unintended children. In this case, education is suppressing fertility; in this niche, education is like a drought. The educated kids have fewer children of their own, and whatever traits the uneducated kids happen to have spread through society because there are now much more of them (at least as a percent of the total). If this trend continues, then the cultural habit of “going to school” may well die out.
In both of these cases, education caused a change in the distribution of genetic traits in the overall population without requiring any genetic predispositions from the students involved. We are looking at the evolution of the whole society.
But this is a highly constrained example; it is rare in places like the modern US to find areas where one village has a school and the next does not. Once schools are everywhere, they’re not going to select for (or against) “living near a school.” The traits that cause a person to attend more years of schooling or do better in school will be less random–traits like conscientiousness, ability to recognize letters, or family income. In an agricultural society with no schools, raw, physical strength may be at a premium as people must wrest their living from the soil, rocks, trees, and beasts. This selects for physical strength. Once we introduce schools, if the better educated have more children, then physical strength becomes less important, and its prominence in the next generation diminishes. The ability to sit in a chair for long hours may be positively selected, leading to a proliferation of this trait.
This is gene-culture co-evolution–a cultural change can shift the balance of genes in a society, and that in turn can cause further cultural changes, which cause more genetic changes.
I would like to pause and note just how annoying the “but you haven’t proven causation!” crowd is:
Why Evolutionary Psychology (Probably) Isn’t Possible: “evolutionary psychologists have not shown that there are specific psychological programs that are written in our bio-historical document” https://t.co/9iXnVgirUN
Imagine if I said that I thought the blood circulates through the body in a loop instead of being generated anew by the heart with every pump, and someone protested that blood couldn’t possibly circulate because I hadn’t shown any way for blood to get from the arteries to the veins and back to the heart.
This was a real debate in physiology. That the heart pumps is obvious. That veins and arteries carry blood is also obvious. That people die if you cut them open and let the blood drain out, though, mystified doctors for centuries.
Capillaries, unfortunately for many patients, are too small to see with the naked eye. Without any mechanism to return blood from the arteries to the heart, doctors refused to believe that it did. They instead believed that blood was produced anew with every heartbeat and was consumed at our extremities. Bleeding patients, therefore, shouldn’t cause any great difficulties.
The fact that we could not see capillaries before the invention of the microscope should not have caused doctors to reject the theory of circulation, only to say that a mechanism had not yet been found to make it work. The circulation hypothesis did a better job of explaining various facts of human anatomy–like the existence of veins carrying blood to the heart and the habit of patients to die after bleeding–than the heart-generation hypothesis.
The insistence on clinging to the older theory due to the lack of a capillary mechanism lead, of course, to the deaths of thousands of patients. (For more on the history of medicine, anatomy, and circulation, I recommend William Bynum’s A Little History of Science.)
How something works is vastly secondary to the question of whether it works at all in the first place. If it works, it works. If you can’t figure out how, you call it magic admit that you don’t know and hope that someday it’ll be clear. What you don’t do is claim that a thing cannot be true or cannot actually work simply because you don’t understand how it happens.
I don’t understand how airplanes stay in the sky, but that doesn’t make them fall down. Reality doesn’t stop just because we don’t understand it; to think that it does is pure, asinine hubris.
The next objection I commonly hear to the idea that cultural changes (like the proliferation of schools) could trigger changes in the genetic makeup of society is that “evolution doesn’t work that fast.”
This is a funny objection. The speed of evolution depends on the nature of the trait we are discussing. Developing a radically new trait, or greatly modifying an existing one, such as developing the ability to breath air instead of water, does indeed take a long time–sometimes millions or even billions of years. But simply modifying the distribution of existing traits in a population can be done nearly instantly–if an invading army lops the heads off of anyone over 5’9″, the average height of the population will fall immediately. From a genetic perspective, this is “negative selection” against height, and the population has “evolved” to be shorter.
(You might object that this is too artificial an example, so consider the inverse: a situation where everyone over a certain size used to die, but due to environmental changes they now survive. Modern obstetrics and the cesarean section have rescued mothers of large babies from the once-common fate of death in childbirth. This was of course often fatal to the infants, as well, and prevented their parents from producing any further children. Large babies were a serious evolutionary problem for our ancestors, but much less so for us, which has probably contributed to the rise in average heights over the past century.)
Usually selection is less extreme, but the point remains: traits that already exist (and vary) in a population, like height, weight, blood type, or temperament, can be selected for (or against) on very short timescales.
In fact, human societies are always selecting for some traits; this means that we are always evolving. The distribution of traits in humans today is not the same as the distribution of traits in humans 20 years ago, much less 100 years ago.
And we can look at all of the things humans are being selected for (or selecting themselves for) and speculate how this will change society. Religious people have more children than atheists, and some religions produce far more children than other religions. This trend is juxtaposed against the massive rise in atheism over the past few decades. Will atheism continue to spread to the children of the religious, or will the religious “core” be effectively immune and overwhelm the remaining agnostics with numbers?
Education (or perhaps it is just a proxy for intelligence) seems to have different effects on different folks and different levels of society. Highschool dropouts have a lot of kids. People with PhDs have a fair number of kids. People who have merely graduated from college, by contrast, have the fewest kids.
Fertility is also different for men and women, with more educated women taking a bigger fertility hit than educated men.
Any discussion of “what’s up with the American middle/working class” has to address facts like these–our country is effectively bifurcating into two “success” models: one very high achieving and one very low achieving. The middle, it seems, is getting cut out.
But we can apply evolutionary theory to much more than humans and their societies. We can analyze ideas, transportation networks, technology, etc.
My first–and probably best–idea in this area was that the idea that the way we transmit ideas influences the nature of our ideas. One of the biggest changes of the past century has been a massive change in the way we communicate, from the rise of mass media to the explosion of social media. Before radio and TV, most people got most of their information from people they knew personally, mostly their families. Today, we get most of our information from total strangers.
Ideas we get from strangers I refer to as meme viruses, (meme as in “unit of idea,” not “funny picture on the internet”) because horizontal transmission resembles the transmission of viruses. Ideas we get from our families I refer to as mitochondrial memes, because vertical transmission resembles the transmission of mitochondrial DNA.
Since the interests of strangers are different from the interests of your close family (your parents are much more interested in you making lots of money, getting married, and making grandbabies than strangers are), they will tend to promote different sorts of ideas. Your parents generally want you to succeed, while strangers would prefer that you do things that help them succeed.
It is this change in the way we communicate, rather than the actions or intentions of any particular group, that I think explains the rise of many modern political trends. (This is the condensed version; I recommend reading one of my posts on memes if you want more.)
I am obviously interested in politics, but not in the conventional sense. I have very little interest in anything associated with particular people in politics, outside of a few historical figures. I have no interest in the latest thing Nancy Pelosi or Emmanuel Macron has been up to. I think people place too much importance on individuals; I am more interested in broad trends (like the spread of technology) that are much bigger and further-reaching than any individual politicians (often their bigger than individual countries).
I’ve come over the years to the conclusion that conventional politics drive people to do (and say) very stupid things. People develop a tribal identity attached to one side or another, and suddenly everything their side does is good and sensible, and everything the other side does is nefarious and dumb. This is not a bad instinct when your enemies have pointy spears and want to turn you into lunch, but it’s terrible when your enemy disagrees with you on optimal interest rates.
My second purpose in founding this blog was to reach out to people who were, as I see it, harmed by the cult-like behavior of modern leftism. When I say “cult-like,” I mean it. Atheism is on the rise, but religious thinking and behavior remains strong. When peoples’ self-identities as “good people” become linked to their membership in political tribes, the threat of excommunication becomes particularly powerful.
… far more unsettling was what happened two weeks later, when knitters who claim to be champions of social justice went after a gay man within the community because he’d written a satirical poem suggesting (correctly) that all the recent anti-racism mobbings might be having a toxic effect on the community. …
The next day, Taylor’s husband Benjamin Till, a composer (who also happens to be Jewish) posted on Sockmatician’s account: “This is Nathan’s husband, Benjamin. At 3 pm today, Nathan was admitted to [the emergency room at] Barnet Hospital. …
Till also wrote on his blog about what had happened:
… Nathan disabled comments when the sheer weight of them became too much, but the following morning, his other Instagram posts, and then his Twitter feed had been hijacked by the haters. The taunts continued. He was a white supremacist, a Nazi apologist…He started obsessively reading the posts but became increasingly worked up, then more and more erratic and then suddenly he snapped, screaming like a terrified animal, smashing boxes and thumping himself. I was forced to wrestle him to the ground and hold onto him for dear life as the waves of pain surged through his body. He made a run for the car keys. He said he wanted to drive at 100 miles per hour until he crashed. I called our doctor and they could hear him screaming in the background and said I was to immediately take him to [the hospital], where he was instantly assessed and put on suicide watch …
This was not the end of Nathan’s ordeal at the hands of people who supposedly believe in “social justice” and helping the powerless, as people continued piling on (yelling at him in public) because of the “harm” he had caused.
I wish I could reach out to everyone like Nathan and tell them that they’re not bad, cults are bad.
The right has its own issues, but I come from a leftist background and so am responding to what I know personally, not abstractly.
From time to time I get a question about the future of HBD (human bio-diversity). The online HBD community was quite vibrant about a decade ago, but many of the brightest lights have faded. Henry Harpending of Westhunter and co-author of The 10,000 Year Explosion has sadly passed away. HBD Chick and Jayman are both occupied with their own lives.
The future of HBD isn’t in blogs or the internet generally (though we can read about it here). It’s over in real genetics research. Yes, there are some subjects that academics don’t want to touch for fear of losing their jobs, but there are many researchers forging paths into fascinating new territory. The field of ancient DNA is unlocking the story of human migration and dispersal, from Neanderthals to Anglo Saxons. Thanks to aDNA, we’ve discovered a whole new Human species, the Denisovans, that interbred with the ancestors of modern Homo sapiens (as did the Neanderthals). We have also discovered “ghost” species in our DNA that we have no name for.
The field of modern DNA is also advancing; we’re learning new things all the time. CRISPRing humans is just one fascinating possibility.
Imagine the ability to remove simple genetic flaws that cause painful and fatal diseases, make ourselves beautiful or smarter. How much are 20 IQ points worth? One study found that people with IQs of 100 average $58,000 a year, while 120s made $128,000. $70,000 a year, averaged over a few decades of working life, (less intelligent people tend to enter the workforce and start earning younger, so it’s not a simple multiplication problem), adds up quickly.
Let’s imagine a scenario in which CRISPR actually works. Only the wealthy–and perhaps those with genetic diseases willing to shell out thousands or covered by insurance–will be able to afford it. The current bifurcation trend will become even more extreme as the poor continue reproducing normally, while the wealthy make themselves smarter, healthier, and prettier.
But if CRISPR confers advantages to society as a whole–for example, if smarter people make fabulous new inventions that everyone benefits from–then we could see foundations, charities, and even welfare programs aimed at making sure everyone has the CRISPR advantage.
After all, if an extra year in school boosts IQ by 3.4 points (I’m not saying it does, but let’s assume), then 6 extra years in school will give you 20.4 points. We pay about $10,600 per pupil per year for public schools, so those six years are worth $63,600. If you can CRISPR 20 IQ points for less, then it’s a better deal.
Of course, CRISPR might just be a pipe dream that gives people cancer.
Whatever happens, the real future of HBD lies in real labs with real budgets, not online blogs. I’m just here to share, discuss, and think–and hopefully there will be enough interesting ideas to discuss for another thousand posts.
Thanks for being part of all these discussions. Blogs are nothing without readers, after all.
In honor family, Thanksgiving, and the discovery that my husband is about as Finnish as Elisabeth Warren is Cherokee, today’s post is on Finnish DNA. (No, I did not just “finish” the field of genetics.)
Finland is one of the few European countries that doesn’t speak an Indo-European language. (Well, technically a lot of them speak Swedish, but obviously that’s because of their long contact with Sweden.) Both Finnish and the Sami language hail from the appropriately named Finno-Ugric family, itself a branch of the larger Uralic family, which spreads across the northern edge of Asia.
While there is one cave that might have housed pre-ice age people in Finland, solid evidence of human occupation doesn’t start until about 9,000 BC (11,000 YA), when the ice sheets retreated. These early Finns were hunter-gatherers (and fishers–one of the world’s oldest fishing nets, from 8300 BC, was found in Finland). For a thousand years or so Baltic Sea was more of a Baltic Lake (called Ancylus Lake), due to some complex geologic processes involving uplift in Sweden that we don’t need to explore, but it seems the lake had some pretty good fishing.
Pottery shows up around 5300 BC, with the “Comb Ceramic Culture” or “Pit-Comb Ware.” According to Wikipedia:
The Xinglongwa are from northern China/inner Mongolia.
This distribution is a pretty decent match to the distribution of Finno-Ugric and Uralic languages before the march of Indo-European (Hungarian arrived in Hungary well after the IE invasion), so it’s pretty decent evidence that the language and pottery went together. Pottery usually indicates the arrival of agricultural peoples (who need pots to store things in,) but in this case, the Comb Ceramic people were primarily nomadic hunter-gatherers/fishers/herders, much like modern people in the far north.
While I usually assume that the arrival of a new toolkit heralds the arrival of a new group of people, the general lifestyle continuity between hunter-gatherers with baskets and hunter-gatherers with pots suggests that they could have been the same people. DNA or more information about their overall cultures would tell the story with more certainty.
Oddly, one variety of pit-comb ware is known as “asbestos ware”, because the locals incorporated asbestos into their pots. The point of asbestos pots, aside from aesthetics (the fibers could make large, thin-walled vessels,) was probably to accommodate the high temperatures needed for metal working.
The Corded Ware people–aka the Yamnaya aka Indo Europeans–showed up around 3,000 BC. They seem to have brought agriculture with them, though Mesopotamian grains didn’t take terribly well to the Finnish weather.
Bronze arrived around 2,000 BC (or perhaps a little later), having spread from the Altai mountains–a route similar to the earlier spread of Comb Ware pottery. (Wikipedia speculates that these bronze artifacts mark the arrival of the Finno-Ugric languages.) Iron arrived around 500 BC.
Since Finland is a difficult place to raise crops, people have gone back and forth between agriculture, hunting, fishing, herding, gathering, etc over the years. For example, around 200 BC, the “hair temperature” pottery disappeared as people transitioned away from agriculture, to a more nomadic, reindeer-herding lifestyle.
A new genetic study carried out at the University of Helsinki and the University of Turku demonstrates that, at the end of the Iron Age, Finland was inhabited by separate and differing populations, all of them influencing the gene pool of modern Finns.
(Gotta love how Science Daily Trumps this as “diverse origins”)
The authors, Oversti et al, actually title their paper “Human mitochondrial DNA lineages in Iron-Age Fennoscandia suggest incipient admixture and eastern introduction of farming-related maternal ancestry” :
Here we report 103 complete ancient mitochondrial genomes from human remains dated to AD 300–1800, and explore mtDNA diversity associated with hunter-gatherers and Neolithic farmers. The results indicate largely unadmixed mtDNA pools of differing ancestries from Iron-Age on, suggesting a rather late genetic shift from hunter-gatherers towards farmers in North-East Europe. …
… aDNA has recently been recovered from c. 1500 year-old bones from Levänluhta in western central Finland18,19. Genomic data from these samples show a Siberian ancestry component still prominently present today, particularly in the indigenous Saami people, and to a lesser extent in modern Finns.
The authors have an interesting observation about a line running through Finland:
Within Finland, an unusually strong genetic border bisects the population along a northwest to southeast axis24,26,27, and is interpreted to reflect an ancient boundary between hunter-gatherer and farmer populations28. The expanse of agriculture north-east of this border was probably limited by environmental factors, especially the length of the growing season.
I thought this part was really neat:
A total of 95 unique complete-mitogenome haplotypes were observed among the 103 complete sequences retrieved: three haplotypes were shared between sampling sites and five within a site. In the latter cases, the placement of the skeletal samples suggests that the shared haplotypes have been carried by different individuals, who may have been maternally related: identical haplotypes (haplogroup U5a2a1e) were obtained from remains of a c. 5-year-old child (grave 18, TU666) and an older woman (grave 7, TU655) from Hollola.
Obviously the death of a child is not neat, but that we can identify relatives in an ancient graveyard is. I have relatives who are all buried near each other, and if some future archaeologist dug them up and realized “Oh, hey, here we have a family,” I think that’d be nice.
The authors discovered something interesting about the direction of the introduction of agriculture.
If you look at a map of Finland, you might guess that agriculture came from the south west, because those are the areas where agriculture is practiced in modern Finland. You’d certainly be correct about the south, but it looks like agriculture was actually introduced from the east–it seems these early farmers didn’t fare well in eastern Finland, and eventually migrated to the west. Alternatively, they may have just failed/given up, and more farmers arrived later from the west and succeeded–but if so, they were related to the first group of farmers.
Overall, the authors found evidence of three different groups in the ancient graveyards: at the oldest site, a Saami-like population (found further south that modern Saami populations); a non-Saami group of hunter gatherers, and Neolithic farmers.
The non-Saami hunter gatherers had high rates of haplogroup U4, which is rare in modern Finns (Saami included). According to the article:
Instead, in contemporary populations, U4 exists in high frequencies in Volga-Ural region (up to 24% in Komi-Zyryans)36 and with lower frequencies around the Baltic Sea, such as in Latvians and Tver Karelians (both around 8%)37. Taking into account that U4 have been prevalent in neighboring areas among Scandinavian10,39,40,41,42,43 and Baltic hunter-gatherers12,13,44, Baltic Comb Ceramics Culture12,13,14 and in Siberia during the Early metal period11, we might be observing ancestries belonging to an earlier layer of ancient inhabitants of the region.
Anyway, it’s an interesting article, so if you’re interested in Finland or polar peoples generally, I hope you give it a read.
Historian and philosopher Emma Houston interrogates the science of electricity and light bulbs
The light switch was at the center of Houston’s first big foray into the history of electricity and lights. The story told in introductory electrical engineering textbooks is relatively simple: flipping the switch up turns the lights “on”; flipping the switch down turns the lights “off.” Whether a switch is in the on or off position has for for decades been seen as an expression of a light bulb’s “true” state or of “light itself.” It is the job of a science historian to discover where these stories come from, and why.
Houston’s doctoral dissertation, published in 2004 as Light Itself: The Search for On and Off in the Electric Circuit does just this, tracing the history of the idea that electromagnetic radiation is turned “on” and “off” by switches found on the wall. Early in the twentieth century, she shows, it was controversial to refer to “light switches” because sometimes electricians accidentally wired around them when installing lights.
But the fact that switches are visible, (unlike electricity) made them useful for enough to two groups of engineers–those building electrical circuits, and those working to untangle the role of electricity in light generation–that the association between switches and light solidified for decades.
Associating “light” with the “light switch,” writes Richardson, has serious consequences, as when engineers tried to develop a “super flashlight” that used two light switches and multiple batteries.
The “super flashlight” was finally abandoned in the development stage when engineers decided it was simpler to use bigger batteries, but in Light Itself, Houston argues that it made the light switch the star of electrical engineering in a way that still reverberates. She points to engineers like Professor Book, whose research focused for decades on using light switches to design home lighting plans. Such a focus was not inevitable, Houston argues: from the 1920s through the 50s, based on evidence in lasers, researchers saw buttons as drivers of light output.
It turns out that “light switches” do not actually cause bulbs to emit electromagnetic radiation. Engineers now understand that light, produced by incandescent bulbs as well as LEDs and compact fluorescents, is the result of numerous interconnected capacitors, resistors, power sources, and wire circuits that all work together. So called “light switches” do not cause light at all–they merely open and close light circuits, allowing electricity to flow (or not) to the bulbs.
But in an interview, Professor Book disagrees with Houston’s account. In Houston’s history, the super flashlight looms large in later researchers’ decision to focus on the switch, but Professor Book responds that research on the super flashlight “did not interest me, it did not impress me, it did not look like the the foundations of a path forward.” Building circuits around the light switch, he says, was not inspired by the popular image of a super bright flashlight with two switches, but “was simply the easiest way to design practical lighting for people’s houses” and that “flipping the switch does actually turn the lights on and off.”
Houston responds that of course we can’t expect actual engineers to know what inspired them or their fields, which is why we need science historians like herself to suss out what was really motivating them.
Author’s note: Professor Houston has degrees in philosophy and literature, but oddly, none in engineering or physics.
It would be interesting to see study of nature vs. nurture opinions among adopted vs. non-adopted children and identical vs. fraternal twins. I'd be interested in views of Chicago Cubs moneyball genius GM Theo Epstein, whose fraternal twin is a guidance counselor.
Of course I believe in the importance of nature a bit more strongly than the average person. But our lives are still the sums of many different factors, some genetic, some nurture, some random. We also have something that feels like free will, crazy as that may sound; we are not doomed to eternally repeat the sins of our parents just because we saw them do something bad when we were three, nor are we condemned to robotically enact whatever flaws are encoded in our DNA. We are complicated.
In the first phase, I was numb: no shock, anger, disappointment—just bewilderment. It was sohard to grasp. Unimaginable. It was hard to think clearly. And yet, a tiny bit of relief. Maybe truth would yield clarity and understanding of my father’s actions. This secondary sensation was the beginning of a wholly unexpected change in my internal being.
The second phase—feeling unmoored—was by far the hardest. Who am I? From where do I come? And who is this unknown man living in my body, coursing through my veins? I would subconsciously shake my hands trying to get him out of me. And worst, with my mother and the father who raised me both deceased, would I ever find the truth, get to the answers I was seeking? When you think you understand your origins, there is no obsessive need to explore and connect; you are satisfied knowing there is an origin and your ancestors and family members can be searched and contacted whenever needed. But when that assumption is taken away, you truly are an alien.
I should note that unlike Professor Schreiber, I had very decent parents; I have nothing to be ungrateful for beyond the normal vagaries of family life.
But the sense of being alien is still there; I always feel myself floating between worlds. There’s the world I was raised in, which I know culturally and can imitate quite effortlessly, (aside from a certain striver efficiency that seems more innate); then the world I talk to on the telephone, where people make the same sort of stupid mistakes as I do, but the cultural context is missing.
The advent of the internet is easing this gab, by the way, as the younger folks in my generation and I share more online culture.
Cultural things can get a good laugh out of you–you and someone else liked the same show, or went to the same park, or enjoyed the same brand of hot dogs–while innate things can strike very deep. Finding out that your brother got in trouble for the same distinct habits that you got in trouble for, or that you see in your own children, is really something. You look at this person and realize that despite this cultural and experiential gulf between you, you understand them–and they understand you.
The fellow in the article ended up with a bunch of new relatives, which he found very rewarding. For most adoptees, contacting biological family is iffy. People who gave you up when you were an infant may not want you in their lives, may not be good people, or may just be dead. But extended family never gave you up; extended family tends not to have all of that awkward parental baggage, either. They’re just potential siblings, aunts, uncles, cousins, etc., you’ve never met, and meeting them can be quite interesting.
I find that people really focus on adoptees’ parents, so I would just like to reiterate that biological families are more than just parents. They are cousins, grandparents, aunts, uncles, siblings, etc. They are entire families. Even people whose biological parents have given them good reason to never contact them (or are dead) may want to contact the rest of their biological families.
And like the good professor, I’ve found that meeting family from very different walks of life than my own has exposed me to very different perspectives. It is interesting seeing how similar people cope with very different situations–the things that stay the same (eg, dorkiness); the things that differ (attitudes toward guns).
Like they say, it’s about half nurture, half nature, half random chance, and half what you make of it.
(Just to be clear, yes, I know that’s not how halves work.)
I realized yesterday that the Left has an odd idea of “purity” that underlies many of their otherwise inexplicable, reality-rejecting claims.
The left has, perhaps unconsciously, adopted the idea that if groups of things within a particular category exist, the groups must be totally independent and not overlap at all.
In the case of genetics, they think that for a genetic group to “exist” and be “real”, it must hail from a single, pure, founding population with no subsequent mixing with other groups. We see this in a recently headline from the BBC: Is this the last of the Aryans?
Deep in India’s Ladakh region live the Aryans, perhaps the last generation of pure-blooded people and holders of possibly the only untampered gene pool left in the world.
These actually-called-Aryans might be fabulous, interesting people, but there is no way they are more pure and “untampered” than the rest of us. The entire sub-headline is nonsense, because all non-Africans (and some Africans) have Neanderthal DNA. They aren’t even pure Homo sapiens! Africans btw have their own archaic DNA from interbreeding with another, non-Neanderthal, human species. None of us, so far as I know, is a “pure” Homo sapiens.
Besides that, the proto-Indo-European people whom these Aryans are descended from where themselves a fusion of at least two peoples, European hunter-gatherers and a so far as I know untraced steppe-people from somewhere about Ukraine.
Further, even if the Aryans settled in their little villages 4,000 years ago and have had very little contact with the outside world over that time, it is highly unlikely that they have had none.
Meanwhile, out in the rest of the world, there are plenty of other highly isolated peoples: The Sentinelese of North Sentinel Island, for example, who will kill you if you try to set foot on their island. There was a pretty famous case just last year of someone earning himself a Darwin award by trying to convert the Sentinelese.
Now let’s look at that word “untampered.” What on earth does that mean? How do you tamper with a genome? Were the rest of us victims of evil alien experiments with CRSPR, tampering with our genomes?
The Chinese might figure out how to produce “tampered” genomes soon, but the rest of us, all of us in the entire world, have “untampered” genomes.
To be honest, I am slightly flabbergasted at this author’s notion that the rest of the people in the world are walking around with “tampered” genomes because our ancestors married some Anatolian farming people 4,000 years ago.
Race does not provide an accurate representation of human biological variation. It was never accurate in the past, and it remains inaccurate when referencing contemporary human populations. Humans are not divided biologically into distinct continental types or racial genetic clusters.
But… no one said they did. At least, not since we stopped using Noah’s sons Shem, Ham, and Japheth going their separate ways after the Flood as our explanation for why races exist.
“See, human races are’t descended from Shem, Ham, and Japheth, therefore races don’t exist!”
Two groups of things need not be completely separate, non-overlapping to nonetheless exist. “Pillows” and “cloth” contain many overlapping traits, for example; there are no traits in “cloth” that do not also exist in “pillows.”
1/ The modern far Left has a political agenda to destroy/deconstruct biological realities under the guise of Social Justice. A common way they go about this is by dishonestly applying univariate statistics to multivariate problems. This is called the Univariate Fallacy.
This fallacy, when deployed, is commonly done using a single sentence buried within an article or essay couched around a broader narrative on the history of a particular type of oppression, such as sexism. Let me give you some recent examples of this fallacy in action.
You’ll remember this @nature piece arguing that sex is a spectrum and that perhaps there are more then 2 sexes, even though over 99.98% of humans can be classified at birth as being unambiguously male or female. … [Link to piece]
In this piece, they hold off deploying the Univariate Fallacy until the second-to-last sentence of a nearly 3500 word essay.
So if the law requires that a person is male or female, should that sex be assigned by anatomy, hormones, cells or chromosomes, and what should be done if they clash? “My feeling is that since there is not one biological parameter that takes over every other parameter, at the end of the day, gender identity seems to be the most reasonable parameter.”
Please read the whole thread. It is very insightful.
For example, if you look at the so called “big five” personality traits, you find only 10% overlap between men and women. This is why it is usually pretty easy to tell if you are talking to a man or a woman. But if you you look at only one trait at a time, there’s a lot more overlap. So the trick is to take a thing with multiple facets–as most things in the real world are–and claim that because it overlaps in any of its facets with any other thing, that it does not exist. It is not pure.
Are our categories, in fact, random and arbitrary? Is there some reality beneath the categories we use to describe groups of people, like “male” and “female,” “young” and “old,” “black” and “white”? Could we just as easily have decided to use different categories, lumping humans by different criteria, like height or eye color or interest in Transformers, and found these equally valid? Should we refer to all short people as “the short race” and everyone who owns a fedora as “untouchables”?
Liberals believe that the categories came first, were decided for arbitrary or outright evil reasons, bear no relation to reality, and our belief in these categories then created them in the world because we enforced them. This is clearly articulated in the AAPA Statement on Race and Racism:
Instead, the Western concept of race must be understood as a classification system that emerged from, and in support of, European colonialism, oppression, and discrimination. It thus does not have its roots in biological reality, but in policies of discrimination. Because of that, over the last five centuries, race has become a social reality that structures societies and how we experience the world.
Race exists because evil Europeans made it, for their own evil benefit, out of the completely undifferentiated mass of humanity that existed before 1492.
This statement depends on the Univariate Fallacy discussed above–the claim that biological races don’t actually exist is 100% dependent on the UF–and a misunderstanding of the term “social construct,” a term which gets thrown around a lot despite no one understanding what it means.
I propose a different sequence of events, (with thanks to Steven Pinker in the Blank Slate for pointing it out): Reality exists, and in many cases, comes in lumps. Plants, for existence, have a lot in common with other plants. Animals have a lot in common with other animals. Humans create categories in order to talk about these lumps of things, and will keep using their categories so long as they are useful. If a category does not describe things well, it will be quickly replaced by a more effective category.
Meme theory suggests this directly–useful ideas spread faster than non-useful ideas. Useful categories get used. Useless categories get discarded. If I can’t talk about reality, then I need new words.
Sometimes, new information causes us to update our categories. For example, back before people figured out much about biology, fungi were a bit of a mystery. They clearly act like plants, but they aren’t green and they seem to grow parasitically out of dead things. Fungi were basically classed as “weird, creepy plants,” until we found out that they’re something else. It turns out that fungi are actually more closely related to humans than plants, but no one outside of a molecular biologist has any need for a category that is “humans and fungi, but not plants,” so no one uses such a category. There are, additionally, some weird plants, like venus flytraps, that show animal-like traits like predation and rapid movement, and some animals, like sponges, that look more like plants. You would not think a man crazy if he mistook a sponge for a plant, but no one looks at these examples, throws up their hands, and says, “Well, I guess plants and animals are arbitrary, socially-constructed categories and don’t exist.” No, we are all quite convinced that, despite a few cases that were confusing until modern science cleared them up, plants, animals, and fungi all actually exist–moving sponges from the “plant” category to the “animal” category didn’t discredit the entire notion of “plants” and “animals,” but instead improved our classification scheme.
Updating ideas and classification schemes slightly to make them work more efficiently as we get more information about obscure or edge cases in no way impacts the validity of the classification scheme. It just means that we’re human beings who aren’t always 100% right about everything the first time we behold it.
To summarize: reality exists, and it comes in lumps. We create words to describe it. If a word does not describe reality, it gets replaced by a superior word that does a better job of describing reality. Occasionally, we get lucky and find out more information about reality, and update our categories and words accordingly. Where a category exists and is commonly used, therefore, it most likely reflects an actual, underlying reality that existed before the world and caused it to come into existence–not the other way around.
The belief that words create reality is magical thinking and belongs over in Harry Potter and animist religion, where you can cure Yellow Fever by painting someone yellow and then washing off the paint. It’s the same childish thinking as believing that monsters can’t see you if you have a blanket over your head (because you can’t see them) or that Bloody Mary will appear in the bathroom mirror if you turn out the lights and say her name three times while spinning around.
Of course, “white privilege” is basically the “evil eye” updated for the modern age, so it’s not too surprised to find people engaged in other forms of mystical thinking, like that if you just don’t believe in race, it will cease to exist and no one will ever slaughter their neighbors again, just as no war ever happened before 1492 and Genghis Khan never went on a rampage that left 50 million people dead.
“Purity” as conceived of in these examples isn’t real. It doesn’t exist; it never existed, and outside of the simplistic explanations people thought up a few thousand years ago when they had much less information about the world, no one actually uses such definitions. The existence of different races doesn’t depend on Ham and Shem; rain doesn’t stop existing just because Zeus isn’t peeing through a sieve. In reality, men and women are different in a number of different ways that render categories like “man” and “woman” functional enough for 99.99% of your daily interactions. Racial categories like “black” and “white” reflect real-life differences between actual humans accurately enough that we find them useful terms, and the fact that humans have migrated back and forth across the planet, resulting in very interesting historical stories encoded in DNA, does not change this at all.
I’d like to wrap this up by returning to the BBC’s strange article on the Aryans:
I asked Dolma if she was excited over her daughter participating in the festival. She replied that not many outsiders came to Biama, and that it was fun to meet foreigners. But even more importantly, she couldn’t wait to see friends from neighbouring villages, brought together by each year by the festival, as well as the chance to dress up, dance and celebrate. If the future generations continue to hold traditional ceremonies and celebrations and keep their vibrant culture alive, perhaps then, they won’t be the last of the Aryans.
One wonders what the author–or the BBC in general–thinks of efforts to keep the British pure or preserve British culture, untouched and unchanged through the millennia. Or is preserving one’s culture only for quaint foreigners whose entertaining exoticism would be ruined if they started acting and dressing just like us? What about those of us in America who think the British have a quaint and amusing culture, and would like it to stick around so we can still be entertained by it? And do the British themselves deserve any say in this, or are they eternally tainted with “impure,” “tampered” bloodlines due to the mixing of bronze-age peoples with Anglo Saxon invaders over a millennium and a half ago, and thus have no right to claim a culture or history of their own?
Goodness, what an idiotic way of looking at the world.
There are three versions of this graph in the paper (check the supplemental materials for two of them), all showing about the same thing. It is supposed to be a graph of population size at different times in the past, and the most incredible thing is that for the past 100,000 years or so, the most numerically dominant populations in Africa were the Baka Pygmies, followed by various Bushmen (San) groups. The authors write:
To unravel the ancient demographic history of the African populations that are present in our data set, we used the Pairwise Sequentially Markovian Coalescent (PSMC) model that analyzes the dynamics of the effective population size over time . We included at least one representative of each of the 15 African populations and two Eurasian samples in the analysis (Additional file 1: Figure S7.1) and considered both the classical mutation rate of 2.5 × 10−8  and the 1.2 × 10−8 mutations per bp per generation reported in other analyses [62, 63]. The demographic trajectories of the sub-Saharan agriculturalist populations are very similar to each other; and only South African Bantu and Toubou individuals differ partly from the rest of sub-Saharan farmer samples; however, their considerable levels of admixture with other North African or hunter-gatherer populations (Fig. 2b) might explain this trend. Therefore, in order to ease visualization, we plotted a Yoruba individual (Yoruba_HGDP00936) and two Ju|‘hoansi individuals as representatives of the sub-Saharan agriculturalist and Khoisan populations, respectively (Fig. 3 and Additional file 1: Figure S7.2 considering a mutation rate of 1.2 × 10−8).
The authors note that the apparent large size of the pygmy groups could have been due to groups splitting and merging and thus getting more DNA variety than they would normally. It’s all very speculative. But still, the Baka Pygmies could have been the absolutely dominant group over central Africa for centuries.
Welcome back to our discussion of Chinua Achebe’s Things Fall Apart. Today I wanted to take a closer look at some of the aspects of traditional Igbo society mentioned in the book.
If you are a regular reader of this blog, you know by now that just as early modern humans (Homo sapiens) mated with Neanderthals and Denisovans somewhere over in Eurasia, some sapiens mated with archaic humans in Africa.
Unfortunately, the state of knowledge about African genomes and especially archaic African genomes is very primitive. Not only does ancient DNA not preserve terribly well in many parts of Africa, but the continent is also rather poor and so people there don’t send their spit to 23 and Me very often to get DNA tested. Thus, sadly, I do not have archaic DNA percents for the Igbo.
Keep in mind that so far, Eurasians measure about 1-4% Neanderthal and Melanesians about 6% Denisovan, so 10% Ghost in west Africans is a pretty big deal (if you’re into archaic DNA.) The authors of the study estimate that the admixture occurred about 50,000 years ago, which is coincidentally about the same time as the admixture in non-Africans–suggesting that whatever triggered the Out of Africa migration may have also simultaneously triggered an Into Africa migration.
If you’re not familiar with some of these groups (I only know a little about the Yoruba,) the Esan, Mende, Gambians, and Yoruba are all speakers of languages from the Niger-Congo family (of which the Bantu languages are a sub-set.) The Niger-Congo family is one of the world’s largest, with 1,540 languages and 700 million speakers. It spread within the past 3,000 years from a homeland somewhere in west Africa (possibly Nigeria) to dominate sub-Saharan Africa. As far as I can tell, the Igbo are quite similar genetically to the Yoruba, and the admixture event happened tens of thousands of years before these groups spread and split, so there’s a good chance that the Igbo have similarly high levels of ghost-pop admixture.
Interestingly, a population related to the Bushmen and Pygmies used to dominate central and southern Africa, before the Bantu expansion. While the Bantu expansion and the admixture event are separated by a good 40 or 50 thousand years, this still suggests the possibility of human hybrid vigor.
Here, we examine 15 African populations covering all major continental linguistic groups, ecosystems, and lifestyles within Africa through analysis of whole-genome sequence data of 21 individuals sequenced at deep coverage. We observe a remarkable correlation among genetic diversity and geographic distance, with the hunter-gatherer groups being more genetically differentiated and having larger effective population sizes throughout most modern-human history. Admixture signals are found between neighbor populations from both hunter-gatherer and agriculturalists groups, whereas North African individuals are closely related to Eurasian populations. Regarding archaic gene flow, we test six complex demographic models that consider recent admixture as well as archaic introgression. We identify the fingerprint of an archaic introgression event in the sub-Saharan populations included in the models (~ 4.0% in Khoisan, ~ 4.3% in Mbuti Pygmies, and ~ 5.8% in Mandenka) from an early divergent and currently extinct ghost modern human lineage.
So the ghost population that shows up in the Pygmies the same ghost population as shows up in the Mende? Looks like it.
There’s a lot of interesting stuff in this paper, but I’d just like to highlight this one graph:
I don’t really understand how they compute these things, much less if this is accurate (though their present estimate for the size of the Han looks pretty good,) but assuming it is, we can say a few things: One, before 100,000 years ago, all of the groups–except the Laal of Chad–tracked closely together in size because they were one group. Most of the groups then got smaller simply because they split up. But there seems to have been some kind of really big population bottleneck a bit over a million years ago.
The other really interesting thing is the absolute Pygmy dominance of the mid-10,000-100,000 year range. The authors note:
It is noteworthy that we observed by PSMC a sudden Ne increase in Baka Pygmy around 30 kya. A similar increase was observed in another study that analyzed several Baka and Biaka samples . In addition, this individual presents the highest average genome-wide heterozygosity compared to the rest of samples (Fig. 1b). Nevertheless, such abrupt Ne increase can be attributed to either a population expansion or episodes of separation and admixture . Further analyses at population level are needed to distinguish between these two scenarios.
The egwugwu ceremony takes place in order to dispute the guilty side of a crime taken place, similar to our court trials… Nine egwugwu represented a village of the clan, their leader known as Evil Forest; exit the huts with their masks on.
Short page; fast read.
The egwugwu ceremony I found particularly interesting. Of course everyone knows the guys in masks are just guys in masks (well, I assume everyone knows that. It seems obvious,) yet in taking on the masks, they adopt a kind of veil of anonymity. In real life, they are people, with all of the biases of ordinary people; under the mask, they take on the identity of a spirit, free from the biases of ordinary people. It is similar to the official garb worn by judges in other countries, which often look quite silly (wigs on English barristers, for example,) but effectively demarcate a line between normal life and official pronouncements. By putting on the costume of the office, the judge becomes more than an individual.
I have long been fascinated by masks, masquerades, and the power of anonymity. Many famous writers, from Benjamin Franklin to Samuel Clemens, published under pseudonyms. The mask implies falseness–on Halloween, we dress up as things that we are not–but it also allows honesty by freeing us from the threat of retribution.
It is interesting that a small, tightly-knit society where everyone knows everyone and social relations are of paramount importance, like the Igbo, developed a norm of anonymizing judges in order to remove judicial decisions from normal social relations and obligations (as much as possible, anyway). Since most Igbo villages did not have kings or other aristocrats to dictate laws, rule was conducted by notable community members who had effectively purchased or earned noble titles. These nobles got to wear the masks and costumes of the egwgwu.
Ok, so it’s getting late and I need to wrap this up. This moment comes in every post.
I know I haven’t said much about the book itself. The plot, narrative, pacing, structure, writing style, etc. To be honest, that’s because I didn’t enjoy it very much. It was interesting for its content, along with a sense of “I’ve been trying to tell people this and I could have saved myself a lot of time by just pointing them to the book. And if this is a book taught in schools (we didn’t read it in my highschool, but I have heard that many people did,) then why aren’t people more aware of the contents?
What was tribal life like before the Europeans got there? Well, women got beaten a lot. Children were murdered to avenge tribal conflicts. Infant mortality was high. In other words, many things were pretty unpleasant.
“Much of the conduct described by anthropologists as conflict management, social control, or even law in tribal and other traditional societies is regarded as crime in modern [nation state] societies.” This is especially clear in the case of violent modes of redress such as assassination, feuding, fighting, maiming, and beating, but it also applies to the confiscation and destruction of property and to other forms of deprivation and humiliation. Such actions typically express a grievance by one person or group against another.
See, for example, when the village burned down Okonkwo’s house for accidentally killing a villager, when they burned down the church for “killing” a deity, or when they took a little girl and killed a little boy in revenge for someone in another village killing one of their women. To the villagers, these were all legal punishments, and the logic of burning down a person’s house if they have killed someone is rather similar to the logic of charging someone a fine for committing manslaughter. Even though Okonkwo didn’t mean to kill anyone, he should have been more careful with his gun, which he knew was dangerous and could kill someone.
Unlike penalties imposed by the state, however, private executions of this kind often result in revenge or even a feud—Moreover, the person killed in retaliation may not be himself or herself a killer, for in these societies violent conflicts between nonkin are virtually always handled in a framework of collective responsibility–or more precisely, collective liability–whereby all members of a social category (such as a family or lineage) are held accountable for the conduct of their fellows.
And, of course, penalties so meted out can be incredibly violent, arbitrary, and selfish, but ignoring that, there’s clearly a conflict when traditional, tribal ways of dealing with problems clash with state-based ways of dealing with problems. Even if everyone eventually agrees that the state-based system is more effective (and I don’t expect everyone to agree) the transition is liable to be difficult for some people, especially if, as in the book, they are punished by the state for enforcing punishments prescribed by their own traditional laws. The state is effectively punishing them for punishing law-breakers, creating what must seem to them a state of anarcho-tyranny.
Co-wife conflict is ubiquitous in polygynous households… Because the Turkana often choose wives from different families in order to broaden their safety net, they typically do not practice sororal [sister-wives] polygyny… When co-wives are relatives, they can more easily share a household and cooperate… But while sororal polygyny is especially common in cultures in the Americas, general polygyny tends to be the usual pattern in Africa. An examination of ethnographic data from 69 nonsororal polygynous cultures fails to turn up a single society where co-wife relations could be described as harmonious. Detailed ethnographic studies highlight the stresses and fears present in polygynous families, including, for example, wives’ concern that other wives might try to poison their children so that their own children might inherit land or property.
There is a well-entrenched schism on the frequency (how often), intensity (deaths per 100,000/year), and evolutionary significance of warfare among hunter-gatherers compared with large-scale societies. To simplify, Rousseauians argue that warfare among prehistoric and contemporary hunter-gatherers was nearly absent and, if present, was a late cultural invention. In contrast, so-called Hobbesians argue that violence was relatively common but variable among hunter-gatherers. … Furthermore, Hobbesians with empirical data have already established that the frequency and intensity of hunter-gatherer warfare is greater compared with large-scale societies even though horticultural societies engage in warfare more intensively than hunter-gatherers. In the end I argue that although war is a primitive trait we may share with chimpanzees and/or our last common ancestor, the ability of hunter-gatherer bands to live peaceably with their neighbors, even though war may occur, is a derived trait that fundamentally distinguishes us socially and politically from chimpanzee societies. It is a point often lost in these debates.