Let’s Talk about Music, Baby


There has been a lot of chatter lately about whether the development of human musical abilities can be explained via some form of sexual selection. Most of this debate has been needlessly heated/involved more insults than it warrants, so I don’t want to pick on any particular people, but all of it seems to have overlooked some basic facts:

  1. Musical success–at least as expressed in our culture–is strongly dimorphic in favor of men.
  2. Music groupies–that is, fans who want to have sex with musicians–are strongly dimorphic in favor of women (especially teens).
  3. Successful musicians have tons of sex.

Let’s run through a little evidence on each of these points. First, talent: 

Wikipedia has a nice list of musicians/bands by # of albums sold. It probably doesn’t include folks like Beethoven, but that’s for the best since it would muck up the data to have artists whose work has been for sale for so long.

The top selling artists, with 250 million or more record sales, are:

The Beatles
Micheal Jackson
Elton John
Led Zeppelin
Pink Floyd

If this list surprises you, you might want to listen to more music.

Men dominate women here 3:1.

I’m not going to list the rest of the top-selling artists on the page, but if we total them up,  I count 27 women/female bands (including two bands that are half women) and 83 male (including the two half-male bands).

Remarkably, 83:27 (and 89:29) is almost exactly 3:1.

Now, some people object that “people liking their music enough to fork over money for it” is not a good measure of “musical talent,” but it is definitely a measure of musical success. If someone is super talented but no one wants to listen to them, well, I am a bit skeptical of the claim that they are talented.

The other common response I get to this runs along the lines of “But we tested musical ability in a lab, and in our experiments, men and women did equally well.”


All that shows is that you got different results; it doesn’t explain why the dimorphism exists in the real world. There are exceedingly few top-selling musicians in the world (118 on Wikipedia’s list, plus or minus a few deaths,) and it’s highly doubtful that anyone of this caliber wandered into a university music lab. It may be that musicians of average quality show no dimorphism at all (or are even biased toward women) while exceptional musicians are disproportionately male, just because there is no particular reason to assume that two different groups of people have the same range of abilities even if they have the same average. In fact, men have a greater range than women in many documented areas, like height and IQ–that is, while there are more men than women in Mensa, there are also more boys than girls in Special Ed.

Second, groupies: 

The first time Scottish concert promoter Andi Lothian booked the Beatles, in the frozen January of 1963, only 15 people showed up. The next time he brought them north of the border… it was as if a hurricane had blown into town.

The night almost unravelled when nervous local police insisted Lothian bring the Beatles on early to satisfy rowdily impatient fans, even though his bouncers were still in the pub. “The girls were beginning to overwhelm us,” remembers Lothian, now 73 and a business consultant. “I saw one of them almost getting to Ringo’s drumkit and then I saw 40 drunk bouncers tearing down the aisles. It was like the Relief of Mafeking! It was absolute pandemonium. Girls fainting, screaming, wet seats. The whole hall went into some kind of state, almost like collective hypnotism. I’d never seen anything like it.”

A Radio Scotland reporter turned to Lothian and gasped, “For God’s sake Andi, what’s happening?” Thinking on his feet, the promoter replied, “Don’t worry, it’s only… Beatlemania.” — Beatlemania: The Screamers and other Tales of Fandom

normal_fans_21.jpg.w300h282As for Elvis:

Gone are all the jerky body movements that once earned Elvis Presley the nickname of ‘The Pelvis’. Gone are all the actions that were dubbed vulgar by his critics. Presley’s stage performance is now restrained. But that did not stop 5,500 wildly excited spectators at the Bloch Arena, Pearl Harbour, Hawaii from going outrageously wild with unreserved enthusiasm last Saturday night. Never have I heard anything like it. Their enthusiasm was fever-pitch, and they were screaming non-stop from start to finish, making it impossible to identify some of the songs he sang. Whether he was talking, singing, raising his eyebrows or just breathing, it was a signal for the volume of excitement to rise higher and higher throughout this fantastic concert.

Hundreds of naval police at this U.S. Navy fortress were detailed to restrain fanatical fans from invading the stage, and they were kept busy for the entire show. …

The climax came when he closed with the all-out rocker ‘Hound Dog’, the signal for the greatest bout of unlimited pandemonium, many of the younger girls going completely berserk! Then came the trickiest part of all – ‘Operation Exit Elvis’ – to get Presley out of the building before the crowd could tear him apart from sheer adoration.

More about the screaming.

Why all of the screaming?

“Screaming girls”—that was a recurring theme in newspaper reviews of Elvis’s stage shows in 1956 and 1957. At almost every stop, the girls screamed so loud that no one could hear Elvis sing. Even the musicians on stage had trouble hearing each other. … Elvis himself explained that at times in 1957 he had to cover his ears with his hands so that he could hear himself sing. …

When I spoke with some women who had attended an Elvis concert back in 1957, most of them admitted they had screamed. …

“We screamed when he came out. I didn’t know I was going to yell and scream. I’d never done that in my whole life. It was spontaneous. …  He could excite you with his music so much. My mom’s gone; I guess she wouldn’t care if I said it now … it was like a sexual experience. It went through your body kind of like that.”

Kurt Cobain’s suicide sent weeping girls into the streets:

A rumor went around in ninth grade English class. We went home and turned on MTV to find out for sure. I remember girls crying in the hallway. …

I was watching the news when I heard, and cried. It was believable and unbelievable, all at the same time. It’s our generation’s “Where were you…?” moment. My husband, our friends, all remember where we were when we heard the news and how devastated we were. …

I was in the bathroom getting ready for school, and my dad yelled “Hey, some guy from that band you like is dead.”

I walked into the living room and saw them playing footage from one of their performances on the TV. And then they said his name. I immediately started bawling. I don’t think my mom made me go to school that day.

In Seattle:

Seattle bid goodbye to Kurt Cobain on April 10 in true grunge-rock style, bursting the ranks of a quickly organized public vigil and leaping into the nearby international fountain, a giant, water-spouting structure some 50 yards wide and ten feet deep that flanks the Flag Pavilion. … Weeping girls wore beauty pageant banners around their middles, made out of the plastic yellow, “POLICE LINE DO NOT CROSS” tape, the same kind of tape which, three days earlier, had criss-crossed the driveway to Cobain and Courtney Love’s home.

At this point, denying that women (especially teen girls) seem to have some sort of thing for rock stars is right up there with denying that men have a thing for fertile young women with hourglass figures.

Third, the sex:

Mick Jagger and Chuck Berry

Groupie sex, oh groupie sex. How many groupies have rockstars actually boned?

Vice has an article titled Elvis was the King of Treating Women like Shit and Luring 14 Year Olds into Bed. Elvis had sex with a lot of teenagers (including Priscilla Marie, who was 14 when they met).

Cracked has a pretty good overview if you’ve never heard of groupies before:

We’ve already written about the sex tents that Van Halen’s Sammy Hagar had installed wherever he performed so that he could disappear mid-solo and indulge himself in a groupie or nine. But that’s not the only way Van Halen was entrepreneurial with his young fans. Let’s take a minute and discuss how original frontman David Lee Roth amused his roadies by sending them out on groupie scavenger hunts.

From his lofty position on the stage, Roth would instruct his roadies to dive into the crowd and collect very specific girls for him to have sex on. The lucky girl would be given a special backstage pass with the initials of the roadie who approached her written in the top corner. If that pass was then among the ones strewn on his floor the next morning, Roth would reward the roadie with a $100 bonus at breakfast the next morning, because exchanging money for sex works up an appetite.

Motley Crue came up with the, uh, creative solution of rubbing burritos on their crotches so their girlfriends wouldn’t smell the scents of groupie sex on them:

He tells Hustler magazine, “We were always f**king other chicks at the studio and backstage… We would take Tommy’s (Lee) van to a restaurant called Noggles to buy these egg burritos and then rub them on our crotches to cover the smell of the girls we had just f**ked.

Let’s hear some more about these “sex tents”:

Before they became a quartet of endless punchlines, Van Halen used to be one of the coolest bands in the world, and they demonstrated their status by having sex with every female who wandered within one mile of their powerful aura. Their career is a filthy memorial to how being in a band is a more powerful aphrodisiac than things like “not looking completely ridiculous,” …

One tour saw the band build a tent directly beneath the stage specifically for Sammy Hagar’s erection. During the mid-show 20-minute guitar solos Eddie Van Halen would launch into each night, Hagar would disappear to the tent and discover a group of naked fans waiting to swallow his penis.

Mick Jagger, by the way, has (at least) eight children via five different women.

Look, I feel a little silly having to spell out in great detail the fact that rock stars get laid a lot. You probably feel a little silly reading it, yet there are people who seem hellbent on arguing that there’s no particular evidence in favor of sexual selection for musical talent.

And no, you can’t explain this away by saying that musicians are “famous” and that women want to have sex with all sorts of famous people. Donald Trump is famous, but he doesn’t have sex tents. Leonardo diCaprio is famous and has legions of fans, but as far as I know, he also doesn’t have sex tents.

I agree that we can’t definitively prove how musical talent evolved among the first humans, (because we don’t have time machines,) but the correlation between sex and music today, in our own society, is overwhelming. A claim that it didn’t have similar effects on our ancestors needs to explain what changed so radically between then and now.

Likewise, we can’t assume that just because music works like this in our own society, it must also work this way in every other society. But conversely, just because something doesn’t work in one society doesn’t imply it doesn’t work in every society. There are a lot of groups out there, and some of them are obviously weird in ways that are’t relevant to everyone else. Some people, for example, like to dress up like anthropomorphic animals and go to conventions. We should be cautious about over-generalizing from small examples. Sure, there might be a random tribe somewhere that with weird traditions like killing any women who see a musical instrument being played, but these tribes generally have fewer people in them than one concert’s worth of screaming Elvis fans.


The Evolution of Horses

lascaux-chinese-horseThe ancestors of horses–small, multi-toed quadrupeds–emerged around 50 million years ago, but horses as we know them (and their wild cousins) evolved from a common ancestor around 6 million years ago. Horses in those days were concentrated in North America, but spread via the Bering land bridge to Eurasia and Africa, where they differentiated into zebras, asses, and “wild” horses.

When humans first encountered horses, we ate them. American horses became extinct around 14,000-10,000 years ago, first in Beringia and then in the rest of the continent–coincidentally about the time humans arrived here. The first known transition from hunting horses to herding and ranching them occurred around 6,000 years ago among the Botai of ancient Kazakhstan, not far from the proto-Indo European homeland (though the Botai themselves do not appear to have been pIEs). These herds were still managed for meat, of which the Botai ate tons, until some idiot teenager decided to impress his friends by riding one of the gol-dang things. Soon after, the proto-Indo-Europeans got the idea and went on a rampage, conquering Europe, Iran, and the Indian subcontinent, (and then a little later North and South America, Africa, Australia, and India again). Those horses were useful.

Oddly, though, it appears that those Botai horses are not the ancestors of the modern horses people ride today–but instead are the ancestors of the Przewalski “wild” horse. The Przewalski was though to be a truly wild, undomesticated species, but it appears to have been a kind of domesticated horse* that went feral, much like the mustangs of the wild west. Unlike the mustang, though, the Przewalski is a truly separate species, with 66 chromosomes. Domesticated horses have 64, so the two species cannot produce fertile hybrids. When exactly the Przewalski obtained their extra chromosomes, I don’t know.

*This, of course, depends on the assumption that the Botai horses were “domesticated” in the first place.

Instead, modern, domesticated horses are believed to have descended from the wild Tarpan, though as far as I know, genetic studies proving this have not yet been done. The Tarpan is extinct, but survived up to the cusp of the twentieth century. (Personally, I’m not putting odds on any major tarpan herds in the past couple thousand years having had 100% wild DNA, but I wouldn’t classify them as “feral” just because of a few escaped domestics.)

Thus the horse was domesticated multiple times–especially if we include that other useful member of the equus family, the ass (or donkey, if you’d prefer). The hardworking little donkey does not enjoy its cousin’s glamorous reputation, and Wikipedia reports,

Throughout the world, working donkeys are associated with the very poor, with those living at or below subsistence level.[45] Few receive adequate food, and in general donkeys throughout the Third World are under-nourished and over-worked.[68]

The donkey is believed to have been domesticated from the wild African ass, probably in ancient Nubia (southern Egypt/northern Sudan). From there it spread up the river to the rest of Egypt, where it became an important work animal, and from there to Mesopotamia and the rest of the world.

Wild African asses still exist, but they are critically endangered.

All of the different species within the equus genus, except the domesticated donkey and its wild African cousins, have different numbers of chromosomes:

przewalski: 66
Horse: 64
Donkey: 62
Onager (Persian wild ass): 56
Kulan: 54/55 (??)
Kiang (Asian wild ass): 51/52 (??)
Grevy’s zebra: 46
common zebra: 44
mountain zebra: 42

As far as I know, they can all cross and make mules, but all of these hybrids are infertile except domestic donkey/wild African donkey crosses. (Your only limit is African wild donkeys being endangered.)

I have no idea while equines have so much chromosomal diversity; dogs have been domesticated for much longer than horses, but are still interfertile with wolves and even coyotes (tbf, maybe horses could breed with tarpans.)

Interestingly, domestication causes a suit of changes to a species’ appearance that are not obviously useful. Recently-domesticated foxes exhibit pelt colors and patterns similar to those of domesticated dogs, not wild foxes. We humans have long hair, unlike our chimp-like ancestors. Horses also have long manes, unlike wild zebras, asses, and tarpans. Horses have evolved, then, to look rather like humans.

Also like humans, horses have different male and female histories. Male horses were quite difficult to tame, and so early domesticators only obtained a few male horses. Females, by contrast, were relatively easy to gentle, so breeders often restocked their herds with wild females. As a result, domesticated horses show far more variation in their mitochondrial DNA than their Y chromosomes. The stocking of herds from different groups of wild horses most likely gave rise to 17 major genetic clusters:

From these sequences, a phylogenetic network was constructed that showed that most of the 93 different mitochondrial (mt)DNA types grouped into 17 distinct phylogenetic clusters. Several of the clusters correspond to breeds and/or geographic areas, notably cluster A2, which is specific to Przewalski’s horses, cluster C1, which is distinctive for northern European ponies, and cluster D1, which is well represented in Iberian and northwest African breeds. A consideration of the horse mtDNA mutation rate together with the archaeological timeframe for domestication requires at least 77 successfully breeding mares recruited from the wild. The extensive genetic diversity of these 77 ancestral mares leads us to conclude that several distinct horse populations were involved in the domestication of the horse.

The wild mustangs of North America might have even more interesting DNA:

The researchers said four family groups (13.8%) with 31 animals fell into haplogroup B, with distinct differences to the two haplogroup L lineages identified.

The closest mitochondrial DNA sequence was found in a Thoroughbred racing horse from China, but its sequence was still distinct in several areas.

The testing also revealed links to the mitochondrial DNA of an Italian horse of unspecific breed, the Yunnan horse from China, and the Yakutia horse from central Siberia, Russia.

Haplogroup B seems to be most frequent in North America (23.1%), with lower frequencies in South America (12.68%) and the Middle East (10.94%) and Europe (9.38%).

“Although the frequency of this lineage is low (1.7%) in the Asian sample of 587 horses, this lineage was found in the Bronze Age horses from China and South Siberia.”

Westhunter suggests that this haplogroup could have originated from some surviving remnant of American wild horses that hadn’t actually been completely killed off before the Spanish mustangs arrived and bred with them. I caution a more prosaic possibility that the Russians brought them while colonizing Alaska and the coast down to northern California. Either way, it’s an intriguing finding.

The horse has been man’s companion for thousands of years and helped him conquer most of the Earth, but the recent invention of internal and external combustion engines (eg, the Iron Horse) have put most horses out to pasture. In effect, they have become obsolete. Modern horses have much easier lives than their hard-working plow and wagon-pulling ancestors, but their populations have shrunk enormously. They’re not going to go extinct, because rich people still like them (and they are still useful in parts of the world where cars cannot easily go,) but they may suffer some of the problems of inbreeding found in genetically narrow dog breeds.

Maybe someday, significant herds of wild horses will roam free again.


Out of Africa revisited? pt 2

nature-siberian-neanderthals-17.02.16-v2The out-of-Africa theory basically says that humans evolved in Africa, then spread in several pulses across the rest of the planet. The first hominin to leave Africa–as far as we know–was Erectus, followed by the Neanderthals/Denisovans, and finally Sapiens. Where exactly smaller, less well-known hominins like Homo Floresiensis fit into the picture we don’t know, yet.)

One of the incredible things about human evolution is just how many other human species we used to co-exist with. We shared this earth with at least 8 other species of human, met and mated with at least 4 of them. Before us came a proliferation of australopithecines.

Today, there is only us. This stunning diversity of upright apes has been winnowed to a single line. Species that had survived for thousands if not millions of years disappeared, either because they died out or were wiped out. We, sapiens, are the last ones standing.

Humans met Neanderthals. We interbred, briefly. Then the Neanderthals died out. Humans met Denisovans. We interbred, briefly. Then the Denisovans disappeared. Humans met so-called “Ghost populations” in west and southern Africa and interbred. The ghosts then disappeared. It’s all very mysterious how every other species of hominin and australopithecine seems to have died out immediately after we sapiens arrived in the area.

This implies, then, that sapiens didn’t live in these areas during the thousands or so years before we wiped out the locals (though some small exceptions may exist.)

So where did we live?

The West African Ghost Population contributed a big chunk of DNA to modern humans a mere 50,000 years ago–around the same time as sapiens were mating with Neanderthals. This seems to have been a much more significant encounter than the one with Neanderthals–perhaps many of these “ghosts” joined the sapiens who moved into their area.

So west Africa was likely not inhabited by modern humans before 50,000 years ago.

Homo naledi is too small to have co-existed with us, effectively ruling out their part of South Africa during that period, and the Pygmies probably interbred with their mystery hominin around 35,000 years ago, so that rules out the Congolese forest area.

The Neanderthal ancestry is in pretty much everyone not in Africa, (and a little in Africa due to recent back-migration) which is pretty strong support for the out-of-Africa theory. The most parsimonious explanation is that a single population split, and half of that population, as it entered Eurasia, encountered Neanderthals, while the other half traveled deeper into Africa and encountered African hominins.

East Africa/the horn of Africa region remains, therefore, the most logical spot to locate Homo sapiens immediately before this splitting phase, but I wouldn’t rule out the Middle East.

On the other hand, Homo sapiens’s ancestor, Homo heidelbergensis, lived in Africa, Europe, and the Middle East for thousands, possibly a million years (depending on how we classify the similar bones of Homo antecessor, who lived near Norfolk, England, about 950,000 years ago. Homo heidelbergensis’s (probable) ancestor, Homo erectus, lived in Africa, Europe, and Asia for over a million years.

Here’s where it gets complicated, because while species like the little hobbits from Flores are clearly different from other varieties of Homo, there are no clear dividing lines between folks like erectus, heidelbergensis, and ergastor. We have a bunch of bones, a few nice skulls, scattered across continents and centuries, from which we try to derive a vague sense of whether this population and that population were similar enough to consider them a single species. Quoting Wikipedia:

Although “Homo ergaster” has gained some acceptance as a valid taxon since its proposal in 1975, ergaster and erectus since the 1980s have increasingly come to be seen as separate (that is, African or Asian) populations of the larger species H. erectus. … The question was described as “famously unresolved” as of 2003.[10] Sura et al (2007) concluded that Homo erectus “was a likely source of multiple events of gene flow to the Eurasian continent”.[11]

The discoveries of the Dmanisi skulls in the South Caucasus since 2005 have re-opened this question. Their great morphological diversity suggests that the variability of Eurasian H. erectus already includes the African fossils dubbed H. ergaster. The discovery of Dmanisi skull 5 in 2013, dated to 1.8 million years ago, now dates evidence of H. erectus in Eurasia as of virtually the same age as evidence for H. ergaster in Africa, so that it is unclear if the speciation of H. erectus/ergaster from H. habilis took place in Africa or Asia.[12] This has reinforced the trend of considering H. ergaster as synonymous with H. erectus, a species which would have evolved just after 2 million years ago, either in Africa or West Asia, and later dispersed throughout Africa and Eurasia.[13][14]

Homo habilis, by contrast, is (so far) only found in east Africa.

What does it mean to evolve in a place? Habilis, as far as we know, actually did evolve in Africa. It didn’t leave Africa; neither did the australopithecines (unless one of those little hobbity folks out in the Philippines turn out to be australopiths, but that would be very remarkable). But after that, “humans” spread from Africa to Europe and Asia with remarkable speed. They lived in England almost a million years ago. And within this range, we seem to have become repeatedly isolated, speciated, and then met back up again when the weather improved.

Personally, I wouldn’t say that the out of Africa theory is wrong. It is still the most parsimonious explanation of human evolutionary history. However, I would say that it simplifies a huge chunk of our history, since for most of our time on this earth, our range has been quite a bit larger than Africa.

Why do Women have breasts?

Paps Anu, Ireland (If you look closely, someone put nipples on top.)

Well, there’s a clickbaity title if ever I wrote one.

Nevertheless, human breasts are strange. Sure, all females of the class mammalia are equipped with mammary glands for producing milk, but humans alone posses permanent, non-functional breasts.

Yes, non-functional: the breast tissue that develops during puberty and that you see on women all around you is primarily fat. Fat does not produce milk. Milk ducts produce milk. They are totally different things.

Like all other mammals, the milk-producing parts of the breasts only activate–make milk–immediately after a baby is born. At any other time, milk production is a useless waste of calories. And when mothers begin to lactate, breasts noticeably increase in size due to the sudden production of milk.

A woman’s normal breast size actually tells you nothing at all about her ability to make milk–if anything, the correlation is the opposite, with obese women (with correspondingly large breasts) having a more difficult time nursing and producing milk:

A number of factors associated with low milk supply have been identified, such as nipple pain, ineffective nursing, hormonal disorders, breast surgery, certain medications, and maternal obesity. …  Research into breast size and milk production shows that milk supply is not dependent on breast size, but rather on the amount of epithelial tissue contained in a breast that is capable of making milk …

However, in addition to baby attachment issues, accumulating evidence shows that a major factor preventing overweight and obese mothers to breastfeed is the inability of their breast epithelial cells to start producing copious amounts of milk after birth. This is often referred to as unsuccessful initiation of lactation. …

a recent study took advantage of breast epithelial cells non-invasively isolated from human milk. In these cells, certain genes are turned on, which enable the cells to gradually make milk as the breast matures during pregnancy, and then deliver it to the baby during breastfeeding.

The study reported a negative association between maternal BMI (body mass index), and the function of a gene that represents the milk-producing cells. This suggested that the breast epithelial tissue is not as mature and ready to make copious amounts of milk in mothers with higher BMI. Most likely, the large breasts of overweight or obese mothers contain more fat cells than milk-making cells, which can explain the low milk supply of many of these mothers.

Therefore, breast size does not necessarily translate to more milk-producing cells or higher ability to make milk.

More fat=less room for milk production.

original source (colors have been changed.)

Interestingly, average cup size varies by country.  Of course the data may not be 100% accurate, and the lumping of everyone together at the national level obscures many smaller groups, like Siberians, but it otherwise still indicates some general trends that we can probably trust.

If breasts don’t actually make milk, then why on Earth do we have them? Why are women cursed with lumpy fat blobs hanging off their chests that have to be carefully smushed into specialized clothing just so we can run without them flopping around painfully?

And for that matter, why do we think they look nice?

One reasonable theory holds that breasts are really just front-butts. Our apish ancestors, like modern chimpanzees, most likely not copulate ad libitum like we do, but only when females were fertile. Female fertility among our chimpish relatives is signaled via a significant swelling and reddening of their rear ends, a clear signal in a species that wears no clothes and often walks on four limbs.

Le Chapeau, Peter Paul Rubens’s portrait of Susanna Fourmer

When humans began walking consistently on two legs, wearing clothes, and looking at each other’s faces, this obvious signal of female fertility was lost, but not our desire to look at rear-ends. So we simply transferred this desire to women’s fronts and selectively had more children with the women who piqued our interests by having more butt-shaped cleavage.

In support of this theory, many women go to fair lengths to increase the resemblance between their ample bosoms and an impressive behind; against this theory is the fact that no other bottom-obsessed species has accidentally evolved a front-butt.

I realized yesterday that there is an even simpler potential explanation: humans are just smart enough to be stupid.

Most of us know that breasts produce milk. Few of us really understand the mechanism of how they produce milk. I had to explain that fat lumps don’t produce milk at the beginning of this post because so few people actually understand this. Far more people think “Big breasts=lots of milk” than think “big breasts=lactation problems.” Humans have probably just been accidentally selecting for big breasts for millennia while trying to select for milk production.

Our breast obsession is cargo-cult lactation.


When we become our own worst enemies

In times of danger, tribes merge; in times of peace, they split.

From Scientific Reports, De novo origins of multicellularity in response to predation:

Here we show that de novo origins of simple multicellularity can evolve in response to predation. We subjected outcrossed populations of the unicellular green alga Chlamydomonas reinhardtii to selection by the filter-feeding predator Paramecium tetraurelia. Two of five experimental populations evolved multicellular structures not observed in unselected control populations within ~750 asexual generations. Considerable variation exists in the evolved multicellular life cycles, with both cell number and propagule size varying among isolates. Survival assays show that evolved multicellular traits provide effective protection against predation. These results support the hypothesis that selection imposed by predators may have played a role in some origins of multicellularity.

If we evolve multicellularity in response to predation, then the inverse–a loss of multicellularity, a splitting apart, can happen when predation is removed. 

The Democrats have faced a bit of controversy lately over the comments of Ilhan Omar (for the non-Americans in the audience, Ilhan Omar is a recently elected representative of Somali Muslim origins.) As Politico reports: 

Then, after being seated on the House Foreign Affairs Committee, Omar was lampooned for a 2012 tweet in which she wrote during an Israeli military campaign in the Gaza Strip, “Israel has hypnotized the world, may Allah awaken the people and help them see the evil doings of Israel.”  

Omar then made an idiotic non apology — “she claimed ignorance of the anti-Semitic trope that conceives of Jewish hypnosis.” 

Whether Omar knew it is a trope or not is irrelevant to the question of whether or not Omar was saying something anti-semitic–and even that is not necessarily grounds for an apology, because people apologize when they actually feel contrite about something. Omar most likely doesn’t.

Muslims have their interests; Jews have different interests. The existence of Israel is a big deal for Jews–it helps ensure that nasty incidents like the Holocaust don’t repeat. The existence of Israel is also a big deal for Palestinians, many of whom, I assume, would be living in the area if Jews weren’t. 

Conflicts over land are nothing new in human history, and it doesn’t require a degree in astrophysics to realize that sometimes groups have conflicting interests. Americans of the non-Jewish or Muslim variety also have their own interests (many desire, for example, that Israel continue existing for their own religious reasons–not hypnosis.) 

The left’s coalition requires different groups to work together (to ally) in their own self-interest, which works if they have bigger enemies to fear. It doesn’t work if they are strong enough to stand on their own feet (or if someone is too dumb to recognize the value of teamwork.) The ideological justification for allying is “intersectionality,” a term which has been bastardized well beyond its original meaning, but is now used to mean “all forms of oppression are really the same thing, so if you oppose one oppression, you must oppose them all.” So if you are against wife beating, you must also be vegan; if you are opposed to the police shooting unarmed black men, you must also be in favor of hijabs. “Interlocking systems of oppression” work to identify a single enemy, a necessary component for unifying people into something like a voting block or a military. 

And it works as long as there actually is a single enemy. 

It falls apart when you don’t have a single enemy, which is of course the world as it actually stands, because lots of groups have different interests and would like each other’s stuff. There isn’t actually anything magically special about cis-hetero-white-Christian-omnivorous-etc-men that makes them any more or less the oppressors of others. Over in Africa, Africans get oppressed by their fellow Africans. In Islamic countries, chickens get eaten by Muslims. In China, Christianity isn’t even remotely significant. 

In a related story, some British schools have recently seen their pro-LGBT curricula attacked by Muslim parents, who are, despite intersectionalist theory, actually pretty anti-homosexuality.

There is no real way to decide between these two points of view. The vast, vast majority of Muslims believe that homosexuality is a sin, and a school that goes out of its way to teach something counter to that is obviously running up against the students’ and parents’ right to their beliefs. Yet gay people also believe, with equal fervor, that homosexuality is morally respectable and they have a right to advocate on their own behalf and have a perfectly sensible desire to reach out to gay Muslims. 

The difficulty with victory is you don’t need your allies anymore; like the US and the USSR at the end of WWII, victorious allies are apt to turn on each other, fighting for what remains of the spoils. This is true of everyone, not just the left–it is just more interesting when it happens on the left because I’ve been pointing out that this would happen for years. 

Of course, some people react to this and say, “clearly the solution to our group splitting apart is to split our group apart; once our group is split, we will all have the same interests and no one will ever fight, just as children never fight with their siblings–hey knock it off in there STOP PUNCHING YOUR BROTHER you have to SHARE THAT TOY–“

Lack of predation => splitting doesn’t just stop at any particular level. 

297px-world_population_v3-svgThe other difficulty with splitting is that we live in a shrinking world. Up until the 1950s, the entire world had fewer than 3 billion people; today we have more than twice that many, and we’re still growing. Our cities are bigger, communities are expanding, transportation is better and faster, and more people have the money necessary to move to new places. More people than ever before are on the internet, watching TV, or otherwise interacting. 

Devour, get devoured, or make something new?

Links Post: Evolution and More

From State of the Science: Finding Human Ancestors in New Places

The Puerto Rican rainforest is beautiful and temporarily low on bugs. (Bugs, I suspect, evolve quickly and so can bounce back from these sorts of collapses–but they are collapses.)

More evidence for an extra Neanderthal or Denisovan interbreeding event in East Asians and Melanesian genomes:

 In addition to the reported Neanderthal and Denisovan introgressions, our results support a third introgression in all Asian and Oceanian populations from an archaic population. This population is either related to the Neanderthal-Denisova clade or diverged early from the Denisova lineage.

(Congratulations to the authors, Mondal, Bertranpetit, and Lao.)

Really interesting study on gene-culture co-evolution in Northeast Asia:

Here we report an analysis comparing cultural and genetic data from 13 populations from in and around Northeast Asia spanning 10 different language families/isolates. We construct distance matrices for language (grammar, phonology, lexicon), music (song structure, performance style), and genomes (genome-wide SNPs) and test for correlations among them. … robust correlations emerge between genetic and grammatical distances. Our results suggest that grammatical structure might be one of the strongest cultural indicators of human population history, while also demonstrating differences among cultural and genetic relationships that highlight the complex nature of human cultural and genetic evolution.

I feel like there’s a joke about grammar Nazis in here.

Why do we sleep? No one knows.

While humans average seven hours, other primates range from just under nine hours (blue-eyed black lemurs) to 17 (owl monkeys). Chimps, our closest living evolutionary relatives, average about nine and a half hours. And although humans doze for less time, a greater proportion is rapid eye movement sleep (REM), the deepest phase, when vivid dreams unfold.

Sleep is pretty much universal in the animal kingdom, but different species vary greatly in their habits. Elephants sleep about two hours out of 24; sloths more than 15. Individual humans vary in their sleep needs, but interestingly, different cultures vary greatly in the timing of their sleep, eg, the Spanish siesta. Our modern notion that people “should” sleep in a solid, 7-9 hour chunk (going so far as to “train” children to do it,) is more a result of electricity and industrial work schedules than anything inherent or healthy about human sleep. So if you find yourself stressed out because you keep taking a nap in the afternoon instead of sleeping through the night, take heart: you may be completely normal. (Unless you’re tired because of some illness, of course.)


Within any culture, people also prefer to rest and rise at different times: In most populations, individuals range from night owls to morning larks in a near bell curve distribution. Where someone falls along this continuum often depends on sex (women tend to rise earlier) and age (young adults tend to be night owls, while children and older adults typically go to bed before the wee hours).

Genes matter, too. Recent studies have identified about a dozen genetic variations that predict sleep habits, some of which are located in genes known to influence circadian rhythms.

While this variation can cause conflict today … it may be the vestige of a crucial adaptation. According to the sentinel hypothesis, staggered sleep evolved to ensure that there was always some portion of a group awake and able to detect threats.

So they gave sleep trackers to some Hadza, who must by now think Westerners are very strange, and found that at any particular period of the night, about 40% of people were awake; over 20 nights, there were “only 18 one-minute periods” when everyone was asleep. That doesn’t prove anything, but it does suggest that it’s perfectly normal for some people to be up in the middle of the night–and maybe even useful.

Important dates in the evolution of human brain genes found:

In May, a pair of papers published by separate teams in the journal Cell focused on the NOTCH family of genes, found in all animals and critical to an embryo’s development: They produce the proteins that tell stem cells what to turn into, such as neurons in the brain. The researchers looked at relatives of the NOTCH2 gene that are present today only in humans.

In a distant ancestor 8 million to 14 million years ago, they found, a copying error resulted in an “extra hunk of DNA,” says David Haussler of the University of California, Santa Cruz, a senior author of one of the new studies.

This non-functioning extra piece of NOTCH2 code is still present in chimps and gorillas, but not in orangutans, which went off on their own evolutionary path 14 million years ago.

About 3 million to 4 million years ago, a few million years after our own lineage split from other apes, a second mutation activated the once non-functional code. This human-specific gene, called NOTCH2NL, began producing proteins involved in turning neural stem cells into cortical neurons. NOTCH2NL pumped up the number of neurons in the neocortex, the seat of advanced cognitive function. Over time, this led to bigger, more powerful brains. …

The researchers also found NOTCH2NL in the ancient genomes of our closest evolutionary kin: the Denisovans and the Neanderthals, who had brain volumes similar to our own.

And finally, Differences in Genes’ Geographic Origins Influence Mitochondrial Function:

“Genomes that evolve in different geographic locations without intermixing can end up being different from each other,” said Kateryna Makova, Pentz Professor of Biology at Penn State and an author of the paper. “… This variation has a lot of advantages; for example, increased variation in immune genes can provide enhanced protection from diseases. However, variation in geographic origin within the genome could also potentially lead to communication issues between genes, for example between mitochondrial and nuclear genes that work together to regulate mitochondrial function.”

Researchers looked at recently (by evolutionary standards) mixed populations like Puerto Ricans and African Americans, comparing the parts of their DNA that interact with mitochondria to the parts that don’t. Since mitochondria hail from your mother, and these populations have different ethnic DNA contributions along maternal and paternal lines. If all of the DNA were equally compatible with their mitochondria, then we’d expect to see equal contributions to the specifically mitochondria-interacting genes. If some ethnic origins interact better with the mitochondria, then we expect to see more of this DNA in these specific places.

The latter is, in fact, what we find. Puerto Ricans hail more from the Taino Indians along their mtDNA, and have relatively more Taino DNA in the genes that affect their mitochondria–indicating that over the years, individuals with more balanced contributions were selected against in Puerto Rico. (“Selection” is such a sanitized way of saying they died/had fewer children.)

This indicates that a recently admixed population may have more health issues than its parents, but the issues will work themselves out over time.

Notes from E. O. Wilson’s Sociobiology


Termite Mound aka Termitary

I recently came across a copy of E. O. Wilson’s Sociobiology (the textbook, 1977 edition) at the secondhand shop.

In The Blank Slate, Steven Pinker gives about the best recommendation I can think of for Wilson’s book:

At Harvard there were leaflets and teach-ins, a protester with a bullhorn calling for Wilson’s dismissal, and invasions of his classroom by slogan-shouting students. When he spoke at other universities, posters called him the “Right-Wing-Prophet of Patriarchy” and urged people to bring noisemakers to his lectures. Wilson was about to speak at a 1978 meeting of the American Association for the Advancement of Science when a group of people carrying placards (one with a swastika) rushed onto the stage chanting, “Racist Wilson, you can’t hide, we charge you with genocide.” One protester grabbed the microphone and harangued the audience while another doused Wilson with a pitcher of water.

Pretty intense for a guy whose career is mostly about ants.

Since it is easier to remember what you have read if you take notes and then transcribe them, and this thing is 574 pages long, I’ll be transcribing some of my notes here as I go along.

The book gives lots of interesting examples of different concepts. For example, in the section on parasitism, there’s an example of a variety of termite that moves into and eats the nests of other termites, thus making a termite mound-in-a-mound, I suppose. To be fair, some termite mounds are about as big as a house and so this is a totally reasonable thing for termites to do.

Chapter 1: The morality of the Gene

Camus said that the only serious philosophical question is suicide.

That is wrong even in the strict sense intended. …

From now on, let’s use “” instead of blockquotes.

Chapter 2: Elementary Concepts

“Genes, like Leibnitz’s monads, have no windows; the higher properties of life are emergent. To specify an entire cell, we are compelled to provide not only the nucleotide sequences but also the identity and configuration of other kinds of molecules placed in and around the cells. To specify an organism requires still more information about both the properties of the cells and their spacial positions. And once assembled, organisms have no windows. A society can be described only as a set of particular organisms, and even then it is difficult to extrapolate the joint activity of this ensemble from the instant of specification, that is, to predict social behavior. …

“Society: a group of individuals belonging to the same species and organized in a cooperative manner. … Yet aggregation, sexual behavior, and territoriality are important properties of true societies, and they are correctly referred to as social behavior. … Since the bond of the society is simply and solely communication, its boundaries can be defined in terms of the curtailment of communication.”

EvX: I have been thinking for a long time about language as effective barriers of culture. Not that culture can’t cross language barriers (movies get dubbed all the time,) but it’s much harder. And since some languages are easier to learn than others, (eg, Finnish is harder than German if you speak English,) cross-language communication is probably easier between some groups than others. The Finns (and a few other European groups) speak non-Indo-European languages, which might make them more functionally isolated within the European context than, say, their neighbors in Sweden.

Back to Wilson:

“Individual: Any physically distinct organism… The distinction between the individual and the colony can be especially baffling in the sponges. … [Hah.]

“Population: A set of organisms belonging to the same species and occupying a clearly delimited area at the same time. This unit… is defined in terms of genetic continuity. In the case of sexually reproducing organisms, the population is a geographically delimited set of organisms capable of freely interbreeding with one another under natural conditions. …

“In sexually reproducing forms, including the vast majority of social organisms, a species is a population or set of populations within which the individuals are capable of freely interbreeding under natural conditions. By definition the members of the species do not interbreed freely with those of other species, however closely related they may be genetically. … In establishing the limits of a species it is not enough merely to prove that genes of two or more populations can be exchanged under experimental conditions. The population must be demonstrated to interbreed fully in the free state.”

[Example: Lions and Tigers can interbreed, yet even in places where their ranges historically overlapped, no one ever reported finding wild ligers or tigons. While they can interbreed in zoos, their behavior is different enough in the wild that it doesn’t happen.]

EvX: And here’s where people ask about Sapiens and Neanderthals. Yes, they interbred. But it looks like they didn’t interbreed much (while they bred plenty with their own,) and it also looks like there’s been a fair amount of selection against Neanderthal DNA in modern humans, winnowing down the genes passed on to us. For example, there’s pretty much no Neanderthal DNA on the Y chromosome, suggesting that any sons of Neanderthal-Sapiens unions were infertile (or didn’t make it at all.) There’s also no (known) Neanderthal mtDNA, suggesting that the matings that did happen involved Neanderthal men with Sapiens women–or if the opposite pairing happened, those children were brought into Neanderthal tribes. At any rate, the pattern is far from complete interfertility.

Back to Wilson:

“A population that differs significantly from other populations belonging to the same species is referred to as a geographic race or subspecies. Subspecies are separated from other subspecies by distance and geographic barriers that prevent the exchange of individuals, as opposed to the genetically based “intrinsic isolating mechanisms” that hold species apart. Subspecies, insofar as they can be distinguished with any objectivity at all, show every conceivable degree of differentiation from other subspecies. At one extreme are the populations that fall along a cline–a simple gradient in the geographic variation of a given character. In other words, a character that varies in a clinal pattern is one that changes gradually over a substantial portion of the entire range of the species. At the other extreme are subspecies consisting of easily distinguished populations that are differentiated from one another by numerous genetic traits and exchange genes across a narrow zone of intergradation.

The main obstacle in dealing with the population as a unit… is the practical difficulty of deciding the limits of particular populations.”

EvX: I would like to point out that humans made up these words to carve up a part of reality that doesn’t always carve that easily. For example, it may be obvious that a wolf species that ranges over thousands of miles is pretty different at the far east and far western extent of its range, but there may be no exact spot in between where the eastern type ends and the western type begins. By contrast, sometimes in human societies you have groups of genetically and culturally distinct people separated for centuries by little more than a road, a wall, a religion, or a language. There is no a priori reason to think that one of these cases fits the definition and the other does not.

But the language we use to delineate groups of ants or wolves or fungi is not the language we use to delineate humans, not just because we wish to be inaccurate, but also because we generally wish to show each other respect. We do so by avoiding language normally reserved for non-humans and using special terms for humans, eg, my offspring are normally referred to as my “children.”

Back to Wilson.

“What is the relation between the population and the society? Here we arrive unexpectedly at the crux of theoretical sociobiology. The distinction between the two categories is essentially as follows: the population is bounded by a zone of sharply reduced gene flow, while the society is bounded by a zone of sharply reduced communication. Often the two zones are the same…

The Multiplier Effect

Social organization is the class of phenotypes furthest removed from the genes. It is derived jointly from the behavior of the individuals and the demographic properties of the population… A small evolutionary change in the behavior pattern of individuals can be amplified into a major social effect by the expanding upward distribution of the effect into multiple facets of life. …

“Even stronger multiplier effects occur in the social insects. … The structure of nests alone can be used to distinguish species within the higher termites.”

EvX: There follows an interesting description of how termites build their mounds, also known as “termitaries.”

“Multiplier effects can speed social evolution still more when an individual’s behavior is strongly influenced by the particularities of its social experience. This process, called socialization, becomes increasingly becomes increasingly prominent as one moves upward phylogenetically into more intelligent species, and it reaches its maximum influence in the higher primates. Although the evidence is still largely inferential, socialization appears to amplify phenotypic differences among primate species.

S”ocialization can also amplify genetically based variation of individual behavior within troops. The temperament and rank of a higher primate is strongly influenced by its early experiences with its peers and its mother.”

EvX: This is a really interesting idea. We hear constantly that ideas like race and gender are social constructs, but what exactly a social construct is we hear far less often. The implication–at least as the phrases are employed–is that they are not real at all, that they are make believe, that we have chosen some random and arbitrary place to carve up reality and that we could use some other random place just as well, but Wilson provides a much better conception: “social constructs” are really amplified ideas about the world around us. In other words, they’re exaggerated stereotypes.

For example, let’s imagine a world in which the average male is taller than the average female, but there’s a lot of variety in height and so there are many individual men who are shorter than a good chunk of women, and likewise many women who are taller than a decent chunk of men. The idea that “men are taller than women” is of course true on average, but also an exaggeration. Men who are particularly short and women who are particularly tall may dislike the fact that they don’t match this Platonic ideal.

Back to Wilson:

“The Evolutionary Pacemaker and Social Drift

“…when evolution involves both structure and behavior, behavior should change first and then structure. In other words, behavior should be the evolutionary pacemaker. … Social behavior also frequently serves as an evolutionary pacemaker. The entire process of ritualization, during which a behavior is transformed by evolution into a more efficient signaling device, typically involves a behavioral change followed by morphological alterations that enhance the visibility and distinctiveness of the behavior.

“The relative lability of behavior leads inevitably to social drift, the random divergence in the behavior and mode of organization of societies or groups of societies. …

“The amount of variance within a population of societies is the sum of the variations due to genetic drift, tradition drift, and their interaction. … Even if the alteration to social structure of a group is due to a behavioral change in a key individual, we cannot be sure that this member was not predisposed to the act by a distinctive capability or temperament conferred by a particular set of genes …

“…Cavalli-Sforza and Feldman (1973) have suggested that in human social evolution the equivalent of an important mutation is a new idea. If it is acceptable and advantageous, the idea will spread quickly. If not, it will decline in frequency and he forgotten. Tradition drift in such instances, like purely genetic drift, has stochastic properties amenable to mathematical analysis.”

EvX: Good old memes. How I love them.

Adaptive Demography

“All true societies are differentiated populations. When cooperative behavior evolves it is put to service by one kind of individual on behalf of another, either unilaterally or mutually…

“The proportions of the demographic classes [like old and young people] also affect the fitness of the group and, ultimately, of each individual member… a deviant population allowed to reproduce for one to several generations will go far to restore the age distribution of populations normal for the species.”

EvX: By “deviant population” he means a population that has more or less of a particular class than is ideal, like if an ant colony lost half of its workers in an accident or a plague wiped out most of the children in a society.

Nature_trees_dark_night_forest_moon_1920x1200“Only if its growth is zero when averaged over many generations can the population have a chance of long life. There is one remaining way to be a success. A population headed for extinction can still possess a high degree of fitness if it succeeds in sending out propagules and creates new populations elsewhere.”

EvX: Your destiny is the stars.

And with that, I’m taking off for the evening.

Reminder: Hunter-Gatherers were not Peace Loving Pacifists

From Balancing Selection at the Prion Protein Gene Consistent with Prehistoric Kurulike Epidemics:

Kuru is an acquired prion disease largely restricted to the Fore linguistic group of the Papua New Guinea Highlands, which was transmitted during endocannibalistic feasts. Heterozygosity for a common polymorphism in the human prion protein gene (PRNP) confers relative resistance to prion diseases. Elderly survivors of the kuru epidemic, who had multiple exposures at mortuary feasts, are, in marked contrast to younger unexposed Fore, predominantly PRNP 129 heterozygotes. Kuru imposed strong balancing selection on the Fore, essentially eliminating PRNP 129 homozygotes. Worldwide PRNP haplotype diversity and coding allele frequencies suggest that strong balancing selection at this locus occurred during the evolution of modern humans.

Our ancestors–the ancestors of all humans–ate each other so often that they actually evolved resistance to prion diseases.

(H/T Littlefoot,)

Of course, they weren’t necessarily hunting each other for the calories (humans are not a very good source of calories compared to other common food sources.) They might have just had a habit of eating the dead from their own communities–which is still pretty gruesome.

Of course, cannibalism didn’t stop when people adopted agriculture. The Aztecs were cannibals“Indigenous Culture Day” celebrates genocidal cannibals who were even worse than Columbus. The Anasazi were cannibals. The word “cannibal” itself comes from the language of the Carib Indians. And of course, there are still-living folks in many other parts of the world who have cannibalized others.

But the idea that ancient humans were some kind of angels is absurd.

Book Club: The 10,000 Year Explosion pt 7: Finale


Niels Bohr
Niels Bohr: 50% Jewish, 100% Quantum Physics

Chapter 7 of The 10,000 Year Explosion is about the evolution of high Ashkenazi IQ; chapter 8 is the Conclusion, which is just a quick summary of the whole book. (If you’re wondering if you would enjoy the book, try reading the conclusion and see if you want to know more.)

This has been an enjoyable book. As works on human evolution go, it’s light–not too long and no complicated math. Pinker’s The Blank Slate gets into much more philosophy and ethics. But it also covers a lot of interesting ground, especially if you’re new to the subject.

I have seen at least 2 people mention recently that they had plans to respond to/address Cochran and Harpending’s timeline of Jewish history/evolution in chapter 7. I don’t know enough to question the story, so I hope you’ll jump in with anything enlightening.

The basic thesis of Chapter 7 is that Ashkenazi massive over-representation in science, math, billionaires, and ideas generally is due to their massive brains, which is due in turn to selective pressure over the past thousand years or so in Germany and nearby countries to be good at jobs that require intellect. The authors quote the historian B. D. Weinryb:

More children survived to adulthood in affluent families than in less affluent ones. A number of genealogies of business leaders, prominent rabbis, community leaders, and the like–generally belonging to the more affluent classes–show that such people often had four, six, sometimes even eight or nice children who reached adulthood…

Einstein and Bohr, 1925

Weinryb cites a census of the town of Brody, 1764: homeowner household had 1.2 children per adult; tenant households had only 0.6.

As evidence for this recent evolution, the authors point to the many genetic diseases that disproportionately affect Ashkenazim:

Tay-Sachs disease, Gaucher’s disease, familial dysautonomia, and two different forms of hereditary breast cancer (BRCA1 and BRCA2), and these diseases are up to 100 times more common in Ashkenazi Jews than in other European populations. …

In principle, absent some special cause, genetic diseases like these should be rare. New mutations, some of which have bad effects, appear in every generation, but those that cause death or reduced fertility should be disappearing with every generation. … one in every twenty-five Ashkenazi Jews carries a copy of the Tay-Sachs mutation, which kills homozygotes in early childhood. This is an alarming rate.

What’s so special about these diseases, and why do the Ashkenazim have so darn many of them?

Some of them look like IQ boosters, considering their effects on the development of the central nervous system. The sphingolipid mutations, in particular, have effects that could plausibly boost intelligence. In each, there is a buildup of some particular sphingolipid, a class of modified fat molecules that play a role in signal transmission and are especially common in neural tissues. Researchers have determined that elevated levels of those sphingolipids cause the growth of more connections among neurons..

There is a similar effect in Tay-Sachs disease: increased levels of a characteristic storage compound… which causes a marked increase in the growth of dendrites, the fine branches that connect neurons. …

We looked at the occupations of patients in Israel with Gaucher’s disease… These patients are much more likely to be engineers or scientists than the average Israeli Ashkenazi Jew–about eleven times more likely, in fact.

Einstein and Oppenheimer, Father of the Atomic Bomb, c. 1950

Basically, the idea is that similar to sickle cell anemia, being heterozygous for one of these traits may make you smarter–and being homozygous might make your life considerably shorter. In an environment where being a heterozygous carrier is rewarded strongly enough, the diseases will propagate–even if they incur a significant cost.

It’s a persuasive argument.

I’d like to go on a quick tangent to Von Neumann’s Wikipedia page:

Von Neumann was a child prodigy. When he was 6 years old, he could divide two 8-digit numbers in his head [14][15] and could converse in Ancient Greek. When the 6-year-old von Neumann caught his mother staring aimlessly, he asked her, “What are you calculating?”[16]

Children did not begin formal schooling in Hungary until they were ten years of age; governesses taught von Neumann, his brothers and his cousins. Max believed that knowledge of languages in addition to Hungarian was essential, so the children were tutored in English, French, German and Italian.[17] By the age of 8, von Neumann was familiar with differential and integral calculus,[18] but he was particularly interested in history. He read his way through Wilhelm Oncken‘s 46-volume Allgemeine Geschichte in Einzeldarstellungen.[19] A copy was contained in a private library Max purchased. One of the rooms in the apartment was converted into a library and reading room, with bookshelves from ceiling to floor.[20]

Von Neumann

Von Neumann entered the Lutheran Fasori Evangélikus Gimnázium in 1911. Wigner was a year ahead of von Neumann at the Lutheran School and soon became his friend.[21] This was one of the best schools in Budapest and was part of a brilliant education system designed for the elite. Under the Hungarian system, children received all their education at the one gymnasium. Despite being run by the Lutheran Church, the school was predominately Jewish in its student body [22] The school system produced a generation noted for intellectual achievement, which included Theodore von Kármán (b. 1881), George de Hevesy (b. 1885), Leó Szilárd (b. 1898), Dennis Gabor (b. 1900), Eugene Wigner (b. 1902), Edward Teller (b. 1908), and Paul Erdős (b. 1913).[23] Collectively, they were sometimes known as “The Martians“.[24] 

One final thing in The 10,000 Year Explosion jumped out at me:

There are also reports of individuals with higher-than-average intelligence who have nonclassic congenital adrenal hyperplasia (CAH)… CAH, which causes increased exposure of the developing fetus to androgens (male sex hormones), is relatively mild compared to diseases like Tay-Sachs. At least seven studies show high IQ in CAH patients, parents, and siblings, ranging from 107 to 113. The gene frequency of CAH among the Ashkenazim is almost 20 percent.

Holy HBD, Batman, that’ll give you a feminist movement.

If you haven’t been keeping obsessive track of who’s who in the feminist movement, many of the early pioneers were Jewish women, as discussed in a recent article by the Jewish Telegraph Agency, “A History of the Radical Jewish Feminists and the one Subject they Never Talked About“:

Heather Booth, Amy Kesselman, Vivian Rothstein and Naomi Weisstein. The names of these bold and influential radical feminists may have faded in recent years, but they remain icons to students of the women’s liberation movement …

The Gang of Four, as they dubbed themselves, were among the founders of Chicago’s Women’s Liberation Union. …

Over weeks, months and years, no subject went unturned, from the political to the sexual to the personal. They were “ready to turn the world upside down,” recalled Weisstein, an influential psychologist, neuroscientist and academic who died in 2015.

But one subject never came up: the Jewish backgrounds of the majority of the group.

“We never talked about it,” Weisstein said.

Betty Friedan was Jewish; Gloria Steinem is half Jewish. There are a lot of Jewish feminists.

Of course, Jews are over-represented in pretty much every intellectual circle. Ayn Rand, Karl Marx, and Noam Chomsky are all Jewish. Einstein and Freud were Jewish. I haven’t seen anything suggesting that Jews are more over-represented in feminism than in any other intellectual circle they’re over-represented in. Perhaps they just like ideas. Someone should come up with some numbers.

Here’s a page on Congenital Adrenal Hyperplasia. The “classic” variety is often deadly, but the non-classic (the sort we are discussing here) doesn’t kill you.

Paul Erdős with Terrence Tao, 1984 (Tao isn’t Jewish, of course.)

I’ve long suspected that I know so many trans people because some intersex conditions result in smarter brains (in this case, women who are better than average at math.) It looks like I may be on the right track.

Well, that’s the end of the book. I hope you enjoyed it. What did you think? And what should we read next? (I’m thinking of doing Pinker’s Blank Slate.)

A theory of male and female Sociopathy, pt 2

Note: this is just a theory, developed in reaction to recent conversations. 

As we were discussing Friday, one form of female sociopathy (at least relevant to this conversation) likely involves manipulating or coercing others into providing resources for her children.

There are a couple of obvious tropes:

  1. The evil stepmother, who shunts resources away from a man’s first child, toward his later children. 
  2. The cuckoldress, who tricks or convinces a man to care for another man’s children (this is not always seen as evil, since the male drive to provide for children is triggered at least partly by their proximity, since men cannot give birth, and thus men feel genuine affection for children who happen to be around them,)
  3. The crazy ex, who sues a man for all he is worth, doing her best to prevent him from being able to provide for any future children. 

How crazy are women? 


22%–slightly more than 1 in 5–women have been diagnosed with a mental illness, at least according to all of the data I’ve seen. Since mental illness peaks during the childbearing ages and falls off quickly after menopause, we can also assume that this rate is closer to 1 in 4 during these years. 

(The dramatic problems our Native American communities are facing is a separate matter, deserving of its own post.)

The odd thing about this data is that mental illness rates are higher for women than men, despite the fact that mental retardation and mental disability rates are higher for men than women. Men are more likely than women to have serious conditions like non-verbal autism and schizophrenia, more likely to be homeless or commit suicide. When things go terribly wrong, the sufferers are disproportionately male (an unfortunate side effect of the Y chromosome causing greater male variability than female variability on a variety of traits.) 

So why on earth do more women than men suffer from mental illness? 

Perhaps some forms of mental illness confer some unexpected benefits on women. 

Many (perhaps most) “mental illnesses” correlate with a single personality trait–neuroticism

“Previously we thought that mental illnesses such as depression, schizophrenia, bipolar disorder, and substance abuse, were completely separate diseases,” Ystrøm says.

But research has now shown that these illnesses are often linked. If you suffer from one mental illness, you are more likely to develop another. And if someone in your immediate family has a psychiatric illness, your risk increases not only for this disorder, but for all other disorders.

These findings have led researchers to suspect that there could be a common underlying factor that increases an idividual’s risk of mental illness, overall. … 

Ystrøm and colleagues have used new statistical methods to look for patterns in personality, mental disorders, genes, and environmental factors, among the twins in the Twin Register. 

And the answer to the question the researchers asked is: yes, neuroticism seems to be the personality trait that best describes the risk of all mental disorders. …

“This one trait doesn’t explain everything. Anyone can develop a mental illness…”

And in women, neuroticism correlates with… more surviving offspring (in at least one study)

Taking an evolutionary approach, we use data from a contemporary polygynous high-fertility human population living in rural Senegal to investigate whether personality dimensions are associated with key life-history traits in humans, i.e., quantity and quality of offspring. We show that personality dimensions predict reproductive success differently in men and women in such societies and, in women, are associated with a trade-off between offspring quantity and quality. In women, neuroticism positively predicts the number of children, both between and within polygynous families. Furthermore, within the low social class, offspring quality (i.e., child nutritional status) decreases with a woman’s neuroticism, indicating a reproductive trade-off between offspring quantity and quality. 

What is neuroticism, in the Big 5 Personality Traits* sense? 

*Note: I am not endorsing or denying all five traits one way or another.

It’s worrying. Mothers who worry more about their offspring have more offspring–though it’s quite easy to imagine that the causality points in the opposite direction as the study’s authors conclude–poor women with lots of skinny babies have more reason to worry about their children than women with a few fat babies. 

When are women most likely to experience mental illness?

Immediately after the birth of a child. It’s called post-partum depression, and it can be very bad–one woman in my moms’ group ended up in the mental hospital after developing post-partum psychosis. Andrea Yates famously drowned her five children during a bout of post-partum depression/psychosis.

Why on earth would women develop a debilitating mental illness at the most vulnerable time in their offspring’s life? Wouldn’t natural selection select rather quickly against anything that makes women worse at taking care of their offspring? 

Let’s turn to everyone’s favorite genetic disease, sickle cell anemia. SCA is famous for being a relatively simple genetic mutation of the sort where if you have one copy of the sickle cell gene, you are less likely to get malaria, and if you have two copies, you tend to die. In areas where malaria is common, the cost of having a quarter of your children die from SCA is lower than the cost of loosing them to malaria. 

Personality traits, including neuroticism, generally exist on a continuum. People may become more neurotic when life warrants it, and less neurotic when they don’t need to worry. A mother with a new baby is in a very vulnerable state–she has just lost a good deal of blood, may not be able to walk, and has an infant to care for every other hour, day and night. It is not a normal state by any measure. It is a time when being extra attentive and extra aware of threats and predators is in a woman’s interest.

It is also a time when women are most in need of help from their mates, relatives, or other friends. Increased neuroticism may also prompt others to attend more closely to the new mother, helping her out. . Increased neuroticism may be so helpful during this time period that a few women getting way too much neuroticism and becoming extremely depressed or even killing their children is a cost outweighed by the increased survival of babies whose mothers had moderate levels of neuroticism. 

Let us note that nature doesn’t care about your feelings. Male praying mantises who allow themselves be eaten by their mates have more offspring than the ones who don’t, but that doesn’t mean male praying mantises enjoy getting eaten. Children who die of sickle

cell anemia don’t much appreciate that their siblings were protected from malaria, either.

An increase in neuroticism immediately after the birth of a baby may prompt a mother to take better care of it, but that doesn’t mean she enjoys the neuroticism. Neither does it mean that post-partum depression is healthy, any more than sickle cell anemia is healthy just because it’s a side effect of a trait that helps people avoid malaria. 

But wait, I have more studies!

Reproductive Fitness and Genetic Risk of Psychiatric Disorders in the General Population

The persistence of common, heritable psychiatric disorders that reduce reproductive fitness is an evolutionary paradox. Here, we investigate the selection pressures on sequence variants that predispose to schizophrenia, autism, bipolar disorder, major depression and attention deficit hyperactivity disorder (ADHD) using genomic data from 150,656 Icelanders, excluding those diagnosed with these psychiatric diseases. … Higher polygenic risk of autism is associated with fewer children and older age at first child whereas higher polygenic risk of ADHD is associated with having more children. We find no evidence for a selective advantage of a high polygenic risk of schizophrenia or bipolar disorder. Rare copy-number variants conferring moderate to high risk of psychiatric illness are associated with having fewer children and are under stronger negative selection pressure than common sequence variants. …

In summary, our results show that common sequence variants conferring risk of autism and ADHD are currently under weak selection in the general population of Iceland. However, rare CNVs that also impact cognition are under stronger selection pressure, consistent with mutation-selection balance. The hypothesis that a selective advantage accounts for the prevalence of sequence variants conferring risk of schizophrenia and bipolar disorder is unproven, but rather this empirical evidence suggests that common sequence variants largely escape selection as their individual effect sizes are weak.

Unfortunately, this study mostly looks at the data in aggregate, instead of breaking it down by males and females. (And I don’t know why they would bother excluding people who actually have the conditions they are trying to study, but perhaps it doesn’t make much difference.) 

Thankfully, they did break down the data by male/female in the tables–Table 1 and Table 2. These tables are confusing, but the takeaway is that mental illness has a bigger effect on male fertility than female fertility. 

Also: Fecundity of Patients with Schizophrenia, Autism, Bipolar Disorder, Depression, Anorexia Nervosa, or Substance Abuse vs. their Unffected Siblings

Results Except for women with depression, affected patients had significantly fewer children (FR range for those with psychiatric disorder, 0.23-0.93; P < 10−10). This reduction was consistently greater among men than women, suggesting that male fitness was particularly sensitive. Although sisters of patients with schizophrenia and bipolar disorder had increased fecundity (FR range, 1.02-1.03; P < .01), this was too small on its own to counterbalance the reduced fitness of affected patients. Brothers of patients with schizophrenia and autism showed reduced fecundity (FR range, 0.94-0.97; P < .001). Siblings of patients with depression and substance abuse had significantly increased fecundity (FR range, 1.01-1.05; P < 10−10). In the case of depression, this more than compensated for the lower fecundity of affected individuals.

Conclusions Our results suggest that strong selection exists against schizophrenia, autism, and anorexia nervosa and that these variants may be maintained by new mutations or an as-yet unknown mechanism. Bipolar disorder did not seem to be under strong negative selection. Vulnerability to depression, and perhaps substance abuse, may be preserved by balancing selection, suggesting the involvement of common genetic variants in ways that depend on other genes and on environment.

Now, this study gets interesting in its graphs: 

From Fecundity of Patients with Schizophrenia, Autism, Bipolar Disorder, Depression, Anorexia Nervosa, or Substance Abuse vs their Unaffected Siblings

In every case, mental illness has a bigger effect on male fertility than female–and in the case of depression, it has no effect on female fertility. 

But wait: 

Same source.

This graph is confusingly labeled, but it is breaking down the correlation on the brothers and sisters of people with mental disorders. So the first dot represents the brothers of people with schizophrenia; the second dot represents the sisters of people with schizophrenia. 

None of these effects are huge, and some of them changed when “comorbidities were included in the analysis,” though it’s not clear exactly what that means–the word comorbidity in this context refers to people with more than one diagnosis. 

For the objectives of this study, we first analyzed each disorder separately without accounting for comorbidities. A secondary analysis was then performed that corrected for comorbidities by analyzing all disorders simultaneously.

So when you analyze all of the disorders together, sisters of schizophrenics had no increased fertility, and neither did the siblings of people with bipolar. Depressed men had average fertility, while depressed women actually had slightly above average fertility. The results for anorexia, substance abuse, and autism didn’t change. 

And from Spain: Seven Dimensions of Personality Pathology are Under Sexual Selection in Modern Spain

Personality variation is increasingly thought to have an adaptive function. This is less clear for personality disorders (PDs)—extreme variants of personality that cause harm in most aspects of life. However, the possibility that PDs may be maintained in the population because of their advantages for fitness has been not convincingly tested. In a sample of 959 outpatients, we examined whether, and how, sexual selection acts on the seven main dimensions of personality pathology, taking into account mating success, reproductive success, and the mediating role of status. We find that, to varying extents, all personality dimensions are under sexual selection. Far from being predominantly purifying, selective forces push traits in diverging, often pathological, directions. These pressures differ moderately between the sexes. Sexual selection largely acts in males through the acquisition of wealth, and through the duration (rather than the number) of mates. This gives a reproductive advantage to males high in persistence–compulsivity. Conversely, because of the decoupling between the number of mates and offspring, the promiscuous strategy of psychopaths is not so successful. Negative emotionality, the most clinically detrimental trait, is slightly deleterious in males but is positively selected in females, which can help to preserve variation. 

It’s interesting that the invention of birth control may have inadvertently selected against promiscuous psychopaths–rather similar to the theory that abortion is responsible for the decrease in crime since the early 90s. 

“Negative emotionality” is likely equivalent to “neuroticism.”

There are two obvious reasons why mental illness might have more of an effect on males than females–one is that mental illness might simply be mores severe for males than females, on average. The second is that mental illness interferes more with holding down a job than with being a housewife, so women with mental illnesses have more options than men. 

Less obvious, though, is that some of these traits might actually be beneficial–in small quantities–for women.

That’s enough for now; let’s continue this discussion on Friday. (Wednesday is book club.)