It seems to me that the genetic structure of India would slow down the spread of selectively advantageous alleles – compared to Europe, say.
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West Hunter 
So, if we fast-forward 200 generations, we might anticipate the formation of Jatis in the USA, with similar segregation, and reduced spread of selectively advantageous alleles (because America has plenty of space for sundown segregation)?
If there were a universal faith that the progeny of modern-day Americans took so seriously that they would kill their own daughters for marrying outside the tribe, perhaps. But you’d have to slice that genetic variation quite thinly. Maybe the Grangerfords and Sherperdsons, amplified from coast to coast.
The lucky Jatis will spread themselves and their advantageous alleles. Imagine that in winter 2014 a peculiarly untreatable (non-kosher) swine influenza virus appears, and only a handful Americans has the gene for resistance. Jatis or no jatis, after 200 generations, the result would be the same.
” Jatis or no jatis, after 200 generations, the result would be the same.”
The chance of a fortuitous mutation arising by chance, and spreading throughout _any_ subset of the population is contingent upon effective population size.
You know, jatis can alter this. By a lot. Even in a country with a billion people.
Should the mutation be significantly advantageous, like resistance to malaria in a swampy tropical region, the lucky jati will outcompete and outbreed all the other jatis. 200 generations is a lot of time. We are talking about theoretical iron-clad jatis, because the real ones are fictional and transitory.
In a big population with a fair amount of gene flow, you can have a number of advantageous mutations spreading at the same time. This process ought to be significantly slower in a population made up of many highly endogenous groups.
Might this also mean multiple solutions to the same problem? I.e. if A occurs first but can’t spread outside the priest types, but B turns up later in the toilet cleaners and can’t spread outside them, then you might have A and B in the population where a Europe like population would move quickly to everyone having A.
That would be interesting if A and B have syngeries which we would find useful, but actually might not have given any selective advantage in an earlier situation (because A or B meet a threshold independently after which there is a diminishing return) – although it is not that interesting outside that situation (as A and B would simply both be selected).
Would the fringes of Europe have a lower frequency for advantageous genes and the center of Europe a greater frequency? Has someone tried to measure this?
Off topic, but there is an article in the New York Times that people here might find interesting:
In particular:
I think they are referring to Qian et al, which found an 8.7 IQ jump from the interaction of COMT and MAOA in boys with ADHD. I shall post it to my MAOA bibliography. GWAS can’t falsify that because these MAOA variants are VNTR. It’s interesting that no one in the science-blog echo-sphere have noted Tielbeek et al, the GWAS of antisocial personality disorder. It is much like Davies et al, the IQ GWAS, and found ASPD to be 55% accounted for by common SNPs. It tried to debunk MAOA research, but, of course, could only look at SNPs. There is a serious disconnect between GWAS results and neurotransmitter genetics research. GWAS cultists sound increasingly like Scientologists. Should people with MDD and schizophrenia stop taking their meds?
I don’t believe it. Repeated careful replication could change my mind.
If the openness of Europe means declining demographics due to enjoying/keeping up the productivity; then back filling with low achieving immigrants; I’m not sure Jatis is the less advantageous path.
Generally, I’m talking about something that takes, and took, thousands of years. Recent European immigration policy is irrelevant. So act as if you understood what I was talking about.
ah so. i just reread Barry Cunliffe’s “Facing the Ocean” and “Between the Oceans” two great books about Euopean history from 8000BC to 1500AD with your ideas about slowly accumulated IQ influencing genes in mind. It makes a lot of sense. All it took was a small technological advantage in you name it…boat building, farming, making war, reducing the infant death rate and one population expanded at the expense of another. Barry Cunliffe never mentions population genetics but it explains a lot.
We of the doomer-porn brigade like to imagine we’re experiencing a sudden extinction event.
Very interesting. Thanks for the link JB. The science -blog echo sphere (nice phrase nooffensebut) ought to be jumping all over any findings that pick up a major IQ increase or decrease because of neurotransmitter genetics. The topic is on the best way to spread advantageous alleles, but what does it matter if we have lifted ourselves out of the malthusian trap so that it is no longer survival of the fittest so that advantageous alleles aren’t spread any faster than disadvantageous ones. Our future lies just aroung the bend when the slow motion train of random chance evolution pulls in to the station and those that choose to hop off and get on the supersonic jet of genetic engineering. But first we have to solve the puzzle why is there so a large variation in human intelligence.
R A Fisher thought that natural selection would be most effective in large panmictic populations where lots of favorable alleles could spread at once. Sewall Wright thought epistatic interactions were very important, and that natural selection would be most effective in subdivided populations where drift let different subpopulations explore different gene combinations. Apparently human beings in Europe and India have arranged themselves to test these theories.
Wright was wrong. On this. In his own way, Fisher was King.
Would be flippant to inquire if your reference is to Fisher King asking the fool “How can you find that which my brightest and bravest could not?”
The mythical figure, not that movie. Also Bruce Campbell.
http://www.psychologytoday.com/blog/pop-psych/201301/5-weak-ideas-about-the-origin-homosexuality-reply
Your work is being popularised.
Finally, somebody else gets it!
I’ve wrestled with this problem for years since my adolescence (I am a gay male), and the more and more I read about evolutionary theory, the deeper and deeper I sank into the morass of personal doubt and uncertainty — because not only are the prevailing scientific theories completely nonsensical, they are, in most cases, utterly retarded.
Really, you don’t need me to tell you how foolish it is to believe that homosexuality is the product of kin selection. Or differential exposure to androgens in the womb. Or differences in parenting methods. (Just how many developmental psychologists have taken a look at the twin and adoption studies?) Or that hideous novelty item trumpeted by the blank slaters, “epigenetics”.
I won’t regale you with the truly baffling (and, in many cases, stultifyingly ignorant) conversations I’ve had regarding the subject with people who ought to know better. You know, PhD candidates in medical genetics, biologists, and the like. It seems the vast majority of people everywhere are just dumb.
Regale away, at least the best. I’m interested.
Bill Hamilton got it. He reviewed our paper, thought it made sense. Alan Grafen had a similar idea and understands it. Mike Bailey does. Out of left field, or maybe right field – Robert Nozick, author Anarchy, State and Utopia, independently had similar thoughts, but didn’t want it generally known. Perhaps it wouldn’t have gone down well at Harvard.
As for those PhD candidates – I don’t think that they’re exactly dumb, but I’m not quite sure what’s wrong with them.Their knowledge base is typically very narrow. And then of course there’s cowardice. Stalin made a big mistake, killing so many people: you can get most people to bark like a seal just by hinting that doing so gives them a chance at tenure, or getting laid, or fitting in better at parties. Most Americans, anyhow.
One poor fellow who took umbrage at my personal beliefs retorted that the germ theory didn’t have a shred of evidence in its favor — because, you see, I hadn’t delved deeply enough in the literature, and so my epistemological priors were totally invalid.
According to him, evolution frequently makes things worse for a species, not better (wtf), so the fact that homosexuality could rise to 3-5% of the population while destroying your reproductive fitness was truly no mystery at all. According to him, “the change of frequency of alleles” is only one of many, equally important mechanisms through which natural selection generates evolutionary change (double wtf), And of course, I was being horribly reductionist if I thought otherwise.
But that wasn’t the worst yet. A grad student I knew once postulated that the healthy psychological benefits of man-on-man bonding from rectal intercourse were sufficient to compensate for the loss of fitness for being gay. He was completely serious, too. Apparently there are lots of primitive societies in the jungle somewhere where this phenomenon is known to exist.
And then there are those chickenheads who postulate that homophobia has co-evolved with male homosexuality throughout the entire history of our species — ergo, no loss of gay genes. More than a few people of these types have accused me of being a radical homophobe.
Either way I nearly got banned from the LGBT center at my university for my heterodox views, and I’ve seen people actually burst into tears over this nonsense. Since then, I’ve learned that it’s best to keep your mouth shut in the face of conventional wisdom — no matter how much it chafes and hurts, you’d better keep the truth bottled up forever, or it might cost your friends, your popularity, or even your career. (I am only a lowly undergraduate in biochemistry, so I’ll assume that it’ll only get worse from this point onward.)
And don’t even get me started on race and gender.
Evolution mostly optimizes at the individual level, which is not always good for the species. Most male bluegills build nests to attract females, then fertilize and protect the eggs. Some (‘sneaky fuckers’) don’t and try to dart by and fertilize the eggs in another’s nest. Parasitic morphs are a burden on a species. Parenthetically, cuckoos probably got their start parasitizing their own species. The results of sexual selection, antlers & peacock tails and such, can be a burden. Driving genes can be bad – look at the t-allele in mice. of course homosexuality isn’t like any of these examples. I remember someone crazy enough to suggest that homosexual were really ‘sneaky fuckers’ pretending disinterest to get in close and reproduce. Only her hairdresser knows for sure! Funny how nobody has ever noticed this happening, over all of history.
As for that grad student – what was his major?
@gcochran:
I am aware of most of those objections (David S. Wilson is silly enough to promote them as evidence for group selection), but I’m afraid W.D. Hamilton’s papers may have been out of his depth. I’m not even sure if he’s ever read The Selfish Gene by Richard Dawkins. Reading too much philosophy of science will turn your brain into mush.
Basically, he was asserting that a trait that leads to an unequivocal loss of fitness in all situations could be favored by evolution over time. He didn’t even try to argue that homosexuality somehow confers advantages to the tribe, which is stupid in a different way. No evolutionary trade-off, no sexual selection, no nothing. It seems I’m not the only one around these parts with a brain disorder.
As for the grad student, archaeology, I believe. He was only a passing acquaintance of mine.
And then there are folks in the humanities. But like I said, stupidity from that academic subculture is only to be expected.
You’d think the truth would offend _me_ more than people with normal hypothalami. But some of the loudest objections I’ve heard come from individuals who have no personal stake in the matter, whatsoever — no immediate gay relatives, no close gay friends, no personal connections with Lambda Legal. Frankly I’m not even sure what motivates such people. It’s hardly been a decade since Lawrence v. Texas.
If you shoot straight from the hip, and call homosexuality a mental illness (which is is, of course — think for yourself, for a change!), that’s when the sparks start to fly.
And of course, I think they would be the first to find a cure for their children, if such a thing were available.
A few other people I know happen to understand it. But they’re Chinese exchange students.
It was a little too late for me, but it might not be too late for future generations.
You don’t know how many people have disowned me because of this. You’d think I were a member of a religious cult, or something along those lines.
Suppose someone made an argument so simple and compelling that people would have to realize that you were making sense. Well, then they’d put their fingers in their ears. You’re telling them something that they don’t want to hear: they’re never going to like it. Even if by some miracle they did tolerate you saying this, first thing you know, some chick would ask you if this dress makes her look fat, and you’d say “It certainly does !”.
It was never my intention in the least to immerse myself in the battle heat of rhetorical fire — but I do have an unfortunate habit of contradicting people when they are hopelessly, needlessly, and obnoxiously wrong. More so when they *ought* to know what they are talking about, and parade their opinions with an unwarranted degree of confidence, but truly haven’t any flippin’ clue. Stupidity from poor schmoes in the humanities who confuse Foucault for a monumental thinker is to be expected, to be sure. But it truly hurts your brain when you realize that a good percentage of physical anthropologists or geneticists haven’t the foggiest clue how biology works.
Whether this tendency arises from plain stupidity or cognitive bias, the end result is the same. Stupid is as stupid does.
So, how does this pathogen propogate itself?
Quarterly Review of Biology paper on Homosexuality
It is free and uses big concepts like canalized behavior through epigenetics or something.
What is so special about humans? Why don’t we see the same in other animals? Well, it seems we do in sheep (rams) but there it seems that about 10% are homosexual.
Questions, questions.
Yes. If we accept the viability of a pathogen hypothesis:
What is it about a same-sex attraction pathogen which would make it work (for the pathogen) in humans (and not various other species where it is not observed)? The major STDs in humans (syphilis, HIV, gonorrhea, chlamydia) are not uniquely human.
And why aren’t we already immune? I would naively expect immunity to a pathogen which targets a simple mechanism and hits fitness strongly to be quick and easy to evolve and carry a large selective advantage to rapidly become ubiquitous.
4th doorman asks “what is so special about humans?”
We are a very prolonged outbreak. Mother nature usually deals with outbreaks (massive increase in population by one species) by disease if predation doesn’t get the job done by itself. Read David Quammen’s fine book “Spillover” for a better desciption than I can provide.
It is not clear to me that the propagation mechanism would be the same for sheep and humans. However, it seems that propagation would be easier in social species and herd species. That is, assuming a virus model.
While I like the germ theory, I can still see a plausible alternative: cant you have favorable selection not “for being gay” but “for having a, say, 20% chance of becoming gay”? this could be selection for further neoteny, with the chance of the wrong outcome being clumsiness due to novelty, kinda like the sickle-cell thing in Africa? Wouldn’t this better explain hunter-gatherer straightness, and the fact that they didn’t massively go gay upon contact? (in other populations we might assume, after thousands of years, since at least the _cinaidi_ of ancient Greece, that alleles “for not becoming gay despite the 20%gay genotype” might have spread)
I think that’s the outlier argument i.e. a trait which is beneficial to people in the middle of the trait’s bell curve and only seriously deleterious to the extreme outliers – a bit like altruism (if combined with ferocious enough group punishment at the low altruism end) or IQ.
(just joking)
(maybe)
For the idea to work might it not be less of a case of a “gay gene” being beneficial but the outlier at the other end of the spectrum being *as* deleterious so there’s a balance?
As a Punnet square say you have trait a and b where the ab outcome is beneficial but *both* the aa and bb outcomes are equally bad then the bell curve could remain in balance – maybe? Not sure.
In the altruism example if ab determined an average level of altruistic behaviour that was just *below* technical altruism while the bb altruists self-deleted then for the bell curve not to drift back towards non-altrusim the pressure would have to be balanced by an equal (cultural?) punishment pressure at the non-altruistic aa end of the spectrum.
In the gay version of this model then the “gay gene” wouldn’t be a gay gene but a “something else” gene with an opposite and would only display as gay if you had too much. Two of the opposite being as equally deleterious as two of the non-gay gene?
So something like a masculine gene and a metrosexual gene where two copies of the masculine gene (in a pacified environment) mostly gets you locked up, two copies of the metrosexual gene makes you gay and one of each is just right (for a pacified environment).
(just thinking aloud)
Question: Why did cats evolve to drink anti-freeze, even though it kills them? Answer: Cats didn’t evolve to drink anti-freeze, there is no anti-freeze in the ancestral feline environment. Cats simply aren’t that well adapted to the modern environment, since it is a very recent development. Consequently, their behavioral programming cannot cope with the modern environment at times.
Question: Why did humans evolve to be homosexual, even though it reduces their chance of reproducing? Answer: Humans didn’t evolve to be homosexual. There is no homosexuality in the ancestral environment (hunter/gatherer). Humans simply aren’t that well adapted to the modern environment, since it is a very recent development. Consequently, their behavioral programming cannot cope with the modern environment at times.
Humans may have been evolving faster since they developed civilization, but nobody can evolve fast enough to keep up with the recent changes in the human environment. Until recently, exclusive and/or preferential homosexuality were extremely rare, although homosexuality may have been used as a leisure activity that supplemented, rather than replaced normal sex (ancient Greece). Prior to the 19th century, homosexuality was not typically considered an exclusive and/or preferential orientation, it was simply seen as an act (often a criminal act.)
Change in the human environment has accelerated, far faster than humans can adapt. Consequently, we see seemingly insane behaviour, such as heterosexuals who don’t bother to reproduce, even though they have plenty of sexual partners and cats who drink anti-freeze. Homosexuality is no different.
Like I said on another thread: whatever is responsible for male homosexuality, it has to be a profound, unprecedented change — one that is so powerful that it confounds the power of human evolution, particularly for adaptive traits that have been optimized over the past tens of millions of years.
You think that cultural change can accomplish this in 3-5% of the male population. You think exposure to a novel social stimulus explains why identical twins raised in the same *family* are just as concordant for sexual orientation as identical twins reared apart.
I don’t think so.
Most surprisingly maladaptive things that people do today involve pursuing attractions that used to work. Sweet things in the past usually had food value, but saccharin fools you. Sex used to produce babies, but birth-control short-circuits the process.
Exclusive same-sex attraction never worked. it’s surprising to see much of it, even in the modern world. It is possible to imagine ways in which this might happen – but then I have a powerful imagination. Nobody has the slightest idea what modern environmental influence might have this maladaptive effect.
Cats lick their feet to clean them: it doesn’t seem that they particularly like antifreeze. It tastes sweet, but cats don’t have a receptor for that.
As the idea that there was no such thing as preferential homosexuaity before the 19th century – I doubt it. That idea was generated by the kind of intellectual that thinks that the Earth is made of green cheese.
It is amazing that some regard lifelong homosexuality as invented in recent times. Ancient literature of full of references to it. Aristophanes who calls his rival satirist Ariston – chaunoproktos (gaping ass) – and he means it. In Rome there was a street of working male homosexuals, and even male+male marriages (Nero and others). The idea of ethereal, platonic Greek homosexual love was generated by Victorian faggots. I didnt know that they also idealized green cheese.
Just for the record: no, there wasn’t any gay marriage in ancient Rome. There were two emperors (Nero and one other) who told the priests to marry them to another man, and the priests decided to go through a such a ceremony to avoid getting killed.
Roman law was explicit: a marriage was a relationship between a man and a woman.