Quotulatiousness

March 10, 2017

BAHFest Sydney 2016: Dr. James O’Hanlon “Why do males have nipples?”

Filed under: Humour, Science — Tags: , , — Nicholas @ 02:00

Published on Feb 26, 2017

Watch Dr. James O’Hanlon discuss how nipples are actually rudimentary balance organs that detect the bodies orientation in space assisting terrestrial mammals stay upright.

The first BAHFest Sydney took place at the Museum of Applied Arts and Sciences on Friday, August 19th 2016.

For more info about BAHFest and upcoming shows in your part of the world, visit http://www.bahfest.com

February 14, 2017

QotD: Explaining why men tend to be slobs, but women very much don’t

Filed under: History, Quotations, Science — Tags: , , , — Nicholas @ 01:00

The central fact that controls the the preferences of both sexes is that bearing children is difficult and dangerous for women, but fertilizing a woman is almost trivially easy for a man. Furthermore, the female investment in childbearing is front-loaded (proportionally more of the risk is before and at birth) while the male investment is back-loaded (proportionately more of the risks and costs are incurred after birth).

Moderns living in a largely disease-free environment seldom realize how cruel and pressing these differences were over most of our species history. But before modern sanitation, death in childbirth was so common that men wealthy enough to afford it expected to have several wives during their lifetimes, losing many of them to childbed fever and other complications.

Also relevant is the extremely high rate of childhood death from infectious diseases and parasites that was characteristic of premodern societies. Disease resistance in humans is highly variable and generally increases with genetic mixing (the same reason a mongrel puppy or kitten is less likely to catch a disease than a purebreed). Thus, both men and women have instincts intended to maximize genetic variety in their offspring in order to maximize the chances that some will survive to reproductive age.

Our instincts evolved to cope with these patterns of life and death. The next piece we need to understand those instincts is what physical beauty means. Recent anthropology revealing strong cross-cultural patterns in the perception of pulchritude is helpful here.

In both sexes, the most important beauty indicators include symmetrical features and a good complexion (clear skin without blemishes, warts, etc.). It turns out these are indicators of resistance to infection and parasites, especially resistance in childhood and during adolescent growth. Good hair is also a health indicator.

In men, physical signs of strength, dexterity, and agility are also favored; this reflects the value female instinctive wiring puts on male specializations in burst exertion, hunting, and warfare. In women, signs of fertility and fitness to bear are favored (healthy and generous breasts, a certain range of hip-to-waist ratios).

Men fixate on physical beauty and youth because under primitive conditions it is a leading indicator of the ability to bear and suckle children. Through most of history, plain or ugly women were bad risks for the next round of infectious diseases — and their children, carrying their genes, were too.

The last piece of the puzzle is that men and women have asymmetrical information about the parentage of their children. A woman is seldom in doubt about which children are the issue of her womb; a man, by contrast, can never be as sure which are the fruit of his seed. Thus, genetic selfishness motivates the woman in a mated pair to sacrifice more for her children than it does the man. This is why women abandon their children far less often than men do.

While women do respond to male good looks, it’s not the agenda-topper for them that it is for men. To understand why this is, it helps to know that the optimal mating strategy for a woman begins with hooking a good provider, a man who will stick around to support the kids in spite of not being as sure that he’s their father as the woman is of being their mother. Where men look for fitness to bear children, women seek the capability and willingness to raise them.

Thus, robust health and infection resistance, while desirable in a potential husband, are not the be-all and end-all. Behavior traits indicating attachment, loyalty, nurturance, and kindness are more important than a tight six-pack. Men instinctively worry about these things less because they know women are more certain of parentage and thus more tightly bonded to their children. Fitness-to-raise also means that indicators of success and social status count for more in men. Men marry health and beauty, women marry security and good prospects.

There is, however, one important exception — one circumstance under which women are just as physical, beauty-oriented, and “shallow” in their mating preferences as men. That’s when they’re cheating.

Both sexes have a genetic-diversity incentive to screw around, but it manifests in different ways. Again, the reason is parentage uncertainty. For a man, diversity tactics are simple — boff as many hot babes as possible, accepting that you don’t know which of their kids are yours and counting on stronger maternal bonding to ensure they will have at least one devoted parent around. Because a woman can be more sure of who her offspring are, her most effective diversity tactic is different — get married to a good provider and then cheat on him.

Under those circumstances, she doesn’t have to value good character in a mating partner as much; hubby, who can’t tell the kids aren’t his, will supply that. Thus the relative value of handsomeness goes up when a woman is taking a lover on the sly. Marrying the lord and screwing the gardener is an old game, and from a genetic-selfishness point of view a very effective one.

Eric S. Raymond, “A Unified Theory of Male Slobbishness and Female Preening”, Armed and Dangerous, 2005-01- 06.

February 6, 2017

The “beer before bread” theory gains strength

Filed under: History, Wine — Tags: , , , — Nicholas @ 04:00

The received wisdom about the transition from hunter-gatherer to agrarian societies is that clans or tribes stopped being nomadic in order to grow crops and secure their food supply more consistently … that growing grain for bread was one of the strongest underlying reasons for the change in lifestyle. That theory is being challenged by researchers who believe the real reason was to produce grains for brewing instead:

The story of humanity’s love affair with alcohol goes back to a time before farming — to a time before humans, in fact. Our taste for tipple may be a hardwired evolutionary trait that distinguishes us from most other animals.

The active ingredient common to all alcoholic beverages is made by yeasts: microscopic, single-celled organisms that eat sugar and excrete carbon dioxide and ethanol, the only potable alcohol. That’s a form of fermentation. Most modern makers of beer, wine, or sake use cultivated varieties of a single yeast genus called Saccharomyces (the most common is S. cerevisiae, from the Latin word for “beer,” cerevisia). But yeasts are diverse and ubiquitous, and they’ve likely been fermenting ripe wild fruit for about 120 million years, ever since the first fruits appeared on Earth.

From our modern point of view, ethanol has one very compelling property: It makes us feel good. Ethanol helps release serotonin, dopamine, and endorphins in the brain, chemicals that make us happy and less anxious.

To our fruit-eating primate ancestors swinging through the trees, however, the ethanol in rotting fruit would have had three other appealing characteristics. First, it has a strong, distinctive smell that makes the fruit easy to locate. Second, it’s easier to digest, allowing animals to get more of a commodity that was precious back then: calories. Third, its antiseptic qualities repel microbes that might sicken a primate. Millions of years ago one of them developed a taste for fruit that had fallen from the tree. “Our ape ancestors started eating fermented fruits on the forest floor, and that made all the difference,” says Nathaniel Dominy, a biological anthropologist at Dartmouth College. “We’re preadapted for consuming alcohol.”

[…]

Flash forward millions of years to a parched plateau in southeastern Turkey, not far from the Syrian border. Archaeologists there are exploring another momentous transition in human prehistory, and a tantalizing possibility: Did alcohol lubricate the Neolithic revolution? Did beer help persuade Stone Age hunter-gatherers to give up their nomadic ways, settle down, and begin to farm?

The ancient site, Göbekli Tepe, consists of circular and rectangular stone enclosures and mysterious T-shaped pillars that, at 11,600 years old, may be the world’s oldest known temples. Since the site was discovered two decades ago, it has upended the traditional idea that religion was a luxury made possible by settlement and farming. Instead the archaeologists excavating Göbekli Tepe think it was the other way around: Hunter-gatherers congregated here for religious ceremonies and were driven to settle down in order to worship more regularly.

H/T to Tamara Keel for the link.

August 15, 2016

Evolved sexual differences

Filed under: Health, Science — Tags: , , , — Nicholas @ 03:00

Amy Alkon on the reason men and women value different attributes in one another:

Why Does Feminism Mean “You Can’t Say That About Women!”?
Feminism, too often these days, means treating women like eggshells, not equals.

If you talk about a woman’s looks — and maybe criticize how much she cares about her looks — you are stomping on hallowed ground, and you’re in for a media reaming (if you make your criticism at all publicly).

By the way, we care about women’s looks — and women care about caring for and showing off their looks — because of our evolved sex differences. Women prioritize status and power in a man and men prioritize physical attractiveness.

This isn’t all we care about in a partner, and it isn’t all we use to judge another person, but these preferences evolved to promote our mating and survival, not out of nowhere. We are living in a modern world with pretty antique psychology — perfect for life in an ancestral environment — so these sex differences in our psychology remain.

I write about these differences in our preferences in my science-based book, Good Manners for Nice People Who Sometimes Say F*ck:

    Many women think men are pretty rude to care so much about a woman’s looks. In a just world, men would have the hots for women simply for the beautiful people they are on the inside. Unfortunately, in the real world, this is just not how male sexuality works. (The penis is not a philanthropic organization and will not get hard because a woman bought a homeless guy a sandwich.)

    Because male sexuality is all about the visuals, men’s magazines are filled with pictures of naked women with freakishly large breasts and women’s magazines are filled with pictures of beauty products and ass-cantilevering $2,000 stilettos. Men evolved to go for signs of reproductively hot prospects — an hourglass figure, youth, clear skin, symmetrical faces and bodies, and long shiny hair: all indicators that a woman is a healthy, fertile candidate to pass on a man’s genes. Women co-evolved to try to make themselves look reproductively hot, though that’s not how we think of it.

July 12, 2016

QotD: Did our distant ancestors select for intelligence?

Filed under: History, Quotations, Science — Tags: , , — Nicholas @ 01:00

This is a special case of one of my favorite Damned Ideas, originally developed by John W. Campbell in the 1960s from some speculations by a forgotten French anthropologist. Campbell proposed that the manhood initiation rituals found in many primitive tribes are a selective machine designed to permit adulthood and reproduction only to those who can demonstrate verbal fluency and the ability to override instinctive fears on verbal command.

Campbell suggests that all living humans are descended from groups of hominids that, having evolved full-human mental capability in some of their members, found the overhead of supporting the dullards too high. So they began selecting for traits correlated with intelligence through initiation rituals timed for just as their offspring were achieving reproductive capacity; losers got driven out, or possibly killed and eaten.

Campbell pointed out that the common elements of tribal initiations are (a) scarring or cicatricing of the skin, opening the way for lethal infections, (b) alteration or mutilation of the genitals, threatening the ability to reproduce, and (c) alteration of the mouth and teeth, threatening the ability to eat. These seem particularly well optimized for inducing maximum instinctive fear in the subject while actually being relatively safe under controlled and relatively hygenic conditions. The core test of initiation is this: can the subject conquer fear and submit to the initiation on the basis of learned (verbal, in preliterate societies) command?

Campbell noticed the first order effect was to shift the mean of the IQ bell curve upwards over generations. The second-order effect, which if he noticed he didn’t talk about, was to start an arms race in initiation rituals; competing bands experimented with different selective filters (not consciously but through random variation). Setting the bar too low or too high would create a bad tradeoff between IQ selectivity and maintaining raw reproductive capacity. So we’re descended from the hominids who found the right tradeoff to push their mean IQ up as rapidly as possible and outcompeted the groups that chose less well.

It doesn’t seem to have occurred to Campbell or his sources, but this theory explains why initiation rituals for girls are a rare and usually post-literate phenomenon. Male reproductive capacity is cheap; a healthy young man can impregnate several young women a day, and healthy young men are instinct-wired to do exactly that whenever they can get away with it. Female reproductive capacity, on the other hand, is scarce and precious. So it makes sense to select the boys ruthlessly and give the girls a pass. Of course if you push this too far you don’t get enough hunters and fighters, but the right tradeoff pretty clearly is not 1-to-1.

Eric S. Raymond, “Selecting for intelligence”, Armed and Dangerous, 2003-11-14.

June 14, 2016

QotD: Romantic love … what is it for?

Filed under: Health, Quotations, Science — Tags: , — Nicholas @ 01:00

It’s all about the encephalization, really. Millions of years ago our hominid ancestors stumbled onto a novel adaptive strategy: be smart, adaptable, and capable of learning rather than purely instinct-driven. Make tools; use fire; invent language.

This strategy required much, much more of our nervous systems. Because intelligence was in fact a winning strategy, we were selected for growing more complex brains capable of doing more information processing. But increasing the logic density of brains is hard; there probably isn’t a path to it through the design space that is rapidly exploitable by small point mutations. So selective pressure made our brains larger, instead.

The fossil record shows that the hominid line encephalized at a breakneck speed compared to the usual leisurely pace of evolutionary change. This had huge consequences; much of human biology is a series of hacks and kluges to support that encephalization, often in stupidly suboptimal ways.

The one that’s relevant here starts from the limited width of the birth canal. Limited, that is, by the pelvic girdle surrounding it. A skull that’s too large won’t fit through. Therefore, the genetic lines that survived were those in which babies are born with small skulls but the ability to grow them much larger by maturity. (And even so, the size of a baby’s skull pushes that limit pretty hard; this is why birth is so much more difficult and dangerous for human females than it is for other primates).

That design (be born with a small skull and upgrade it outside the womb) implied a long juvenile period between birth and physical maturity. In fact the human brain doesn’t completely finish configuring and rewiring itself until around age 25. And the long juvenile period probably also explains the exceptionally long human lifespan; whatever had to be altered in the development clock to defer stabilization into the final adult configuration probably also delayed the inset of senescence. (Direct evidence for this theory is the rare disease “progeria”).

And the dominoes kept falling. The long juvenile period implied offspring that would be incapable of fending for themselves for an unprecedently long time – on the order of decades rather than the few months to a year typical for other mammals. Consequently the selective value of extended cooperation between the parents went way, way up relative to even our nearest animal kin.

Romantic love works as an an evolved mechanism for keeping mated pairs cooperating long enough to raise multiple children. Here again, selection favors those who love more because they get to launch more offspring. We are, in fact, made to fall in love – and it would only be surprising if the mechanism for establishing it were not simple, robust, and easily triggered.

Eric S. Raymond, “Love is the simplest thing”, Armed and Dangerous, 2015-01-15.

June 1, 2016

QotD: The evolutionary advantage of conformity

Filed under: Politics, Quotations, Science — Tags: , , — Nicholas @ 01:00

In the environment of evolutionary adaptedness (EEA) an individual could not survive outside the group of their birth and so conformity was a matter of life and death. Conform or be cast out. Conformity to arbitrary convention was not in fact arbitrary but signalled affiliation. Conformity banded groups together.

Today, however, conformity is often counter-productive. Trying to enforce the arbitrary conventions of one’s in-group impedes social cooperation on the scale that makes modernity possible. Conformity also slows the development of new ideas and new ways of doing things — the essence of growth and progress. Even though conformity is now counter-productive the desire to conform and to enforce conformity is buried deep–the atavism of social justice.

Individualism and liberalism are foundational ideas for modernity but these adult ideas battle the desire to conform in our childish hearts.

Alex Tabarrok, “The Developmental Roots of Conformity Bias”, Marginal Revolution, 2016-05-20.

March 19, 2016

QotD: Dieting as a substitute religion

Filed under: Health, Quotations — Tags: , , — Nicholas @ 01:00

A current New York Times news story, What If It’s All Been A Big Fat Lie, entertainingly chronicles the discovery that low-fat diets are bad for people. More specifically, that the substitution of carbohydrates like bread and pasta and potatoes for meat that we’ve all had urged on us since the early 1980s is probably the cause of the modern epidemic of obesity and the sharp rise in diabetes incidence.

I have long believed that most of the healthy-eating advice we get is stone crazy, and the story does tend to confirm it. One of my reasons for believing this is touched on in the article; what we’re told is good for us doesn’t match what humans “in the wild” (during the 99% of our species history that predated agriculture) ate. The diet our bodies evolved to process doesn’t include things like large amounts of milled grain or other starches. Our hunter-gatherer ancestors ate wild vegetables (especially tubers) and meat whenever they could get it.

[…]

But the evolutionary analysis only tells us what we probably should be eating. It doesn’t explain how the modern diet has come to be as severely messed up as it is — nor why the advice we’ve been getting on healthy eating over the last twenty years has been not merely bad but perversely wrong.

The answer is, I think, implicit in the fact that “health food” has a strong tendency to be bland, fibrous, and nasty — a kind of filboid studge that we have to work at convincing ourselves we like rather than actually liking. Which is, if you think about it, nuts. Human food tropisms represent two million years of selective knowledge about what’s good for our bodies. Eating a lot of what we don’t like is far more likely to be a mistake than eating things we do like, even to excess.

Why do we tend to treat our natural cravings for red meat and fat as sins, then? Notice the similarity between the rhetoric of diet books and religious evangelism and you have your answer. Dietary mortification of the flesh has become a kind of secular asceticism, a way for wealthy white people with guilt feelings about their affluence to demonstrate virtue and expiate their imagined transgressions.

Once you realize that dieting is a religion, the irrationality and mutual contradictions become easier to understand. It’s not about what’s actually good for you, it’s about suffering and self-denial and the state of your soul. People who constantly break and re-adopt diets are experiencing exactly the same cycle of secondary rewards as the sinner who repeatedly backslides and reforms.

This model explains the social fact that the modern flavor of “health”-based dietary piety is most likely to be found in people who don’t have the same psychological needs satisfied by an actual religion. Quick now: who’s more likely to be a vegetarian or profess a horror of “junk food” — a conservative Christian heartlander or a secular politically-correct leftist from the urban coasts?

Eric S. Raymond, “Diet Considered as a Bad Religion”, Armed and Dangerous, 2002-07-17.

January 19, 2016

QotD: Male brutality as an evolutionary advantage

Filed under: Health, History, Quotations — Tags: , , — Nicholas @ 01:00

Perhaps more important than piling up more examples to attest the phenomenon is giving a little thought to why female masochism occurs. Like other sex traits, it is an evolutionary adaptation. I am going to go way out on a limb and suggest that early hominid males may not have been quite so delicate as Tom Fleming, who becomes ill at the very thought of a woman being struck. African men are, by all accounts, pretty quick with their fists to this day. Gallantry is an achievement of civilization, not a part of our primitive nature.

Now, females in our “environment of evolutionary adaptation” were dependent on males for mating, protection, and access to resources. These males were bigger and stronger than females and could easily hurt them if angered or displeased. If our female ancestors had been delicate snowflakes unable to endure life with such brutes, we would not be here today. In other words, women adapted to male brutality, including occasional violence, learning how to get through or around it.

Think for a moment, men, how you would learn to behave if you were dependent for survival on an unpredictable and often violent creature larger and stronger than yourself. You would learn not simply to take what you wanted. You would learn to act when his back is turned, to use indirection, deception, manipulation. You would learn to conceal your true thoughts and keep Big Boy confused as to your true intentions. You would, in short, learn to act like a woman.

The battle of the sexes is a contest of force vs. cunning. Yes, civilized men learn to control their aggressive impulses and not beat women up every time they feel irritation with them. In the modern West, men have largely renounced the use of their natural weapon for controlling women, i.e., force. Have women renounced the use of their own weapons against men? Certainly we cannot expect women to shed millennial evolutionary adaptations automatically the instant men learn to behave.

F. Roger Devlin, “The Question of Female Masochism”, Counter-Currents Publishing, 2014-09-17.

April 24, 2015

Framing every conservation issue in terms of “extinction” is counter-productive

Filed under: Environment, Science — Tags: , , — Nicholas @ 04:00

Stewart Brand wants us to stop presenting so many conservation concerns in the headline-grabbing “Fluffy Bunnies At Risk!” format:

The way the public hears about conservation issues is nearly always in the mode of ‘[Beloved Animal] Threatened With Extinction’. That makes for electrifying headlines, but it misdirects concern. The loss of whole species is not the leading problem in conservation. The leading problem is the decline in wild animal populations, sometimes to a radical degree, often diminishing the health of whole ecosystems.

Viewing every conservation issue through the lens of extinction threat is simplistic and usually irrelevant. Worse, it introduces an emotional charge that makes the problem seem cosmic and overwhelming rather than local and solvable. It’s as if the entire field of human medicine were treated solely as a matter of death prevention. Every session with a doctor would begin: ‘Well, you’re dying. Let’s see if we can do anything to slow that down a little.’

Medicine is about health. So is conservation. And as with medicine, the trends for conservation in this century are looking bright. We are re-enriching some ecosystems we once depleted and slowing the depletion of others. Before I explain how we are doing that, let me spell out how exaggerated the focus on extinction has become and how it distorts the public perception of conservation.

Many now assume that we are in the midst of a human-caused ‘Sixth Mass Extinction’ to rival the one that killed off the dinosaurs 66 million years ago. But we’re not. The five historic mass extinctions eliminated 70 per cent or more of all species in a relatively short time. That is not going on now. ‘If all currently threatened species were to go extinct in a few centuries and that rate continued,’ began a recent Nature magazine introduction to a survey of wildlife losses, ‘the sixth mass extinction could come in a couple of centuries or a few millennia.’

The fossil record shows that biodiversity in the world has been increasing dramatically for 200 million years and is likely to continue. The two mass extinctions in that period (at 201 million and 66 million years ago) slowed the trend only temporarily. Genera are the next taxonomic level up from species and are easier to detect in fossils. The Phanerozoic is the 540-million-year period in which animal life has proliferated. Chart created by and courtesy of University of Chicago paleontologists J. John Sepkoski, Jr. and David M. Raup.

The fossil record shows that biodiversity in the world has been increasing dramatically for 200 million years and is likely to continue. The two mass extinctions in that period (at 201 million and 66 million years ago) slowed the trend only temporarily. Genera are the next taxonomic level up from species and are easier to detect in fossils. The Phanerozoic is the 540-million-year period in which animal life has proliferated. Chart created by and courtesy of University of Chicago paleontologists J. John Sepkoski, Jr. and David M. Raup.

The range of dates in that statement reflects profound uncertainty about the current rate of extinction. Estimates vary a hundred-fold – from 0.01 per cent to 1 per cent of species being lost per decade. The phrase ‘all currently threatened species’ comes from the indispensable IUCN (International Union for Conservation of Nature), which maintains the Red List of endangered species. Its most recent report shows that of the 1.5 million identified species, and 76,199 studied by IUCN scientists, some 23,214 are deemed threatened with extinction. So, if all of those went extinct in the next few centuries, and the rate of extinction that killed them kept right on for hundreds or thousands of years more, then we might be at the beginning of a human-caused Sixth Mass Extinction.

April 2, 2015

“… women think about their bodies in much more complicated ways than men do”

Filed under: Health, Science — Tags: , — Nicholas @ 04:00

Amanda Smith on some of the reasons why human male and female shapes are so different from one another, unlike most mammals:

“It just seems that women think about their bodies in much more complicated ways than men do, and that’s kind of bewildering when you’re a man,” he says.

Apart from mere curiosity, Bainbridge has a professional interest: “I’d always thought it was strange that humans are the one species where our females are curvy — you don’t really see that in other species”.

He addresses that question in his book: Curvology: The Origins and Power of Female Body Shape.

At birth, he writes, human babies are around 12 per cent fat by weight. Throughout childhood that average fat level remains consistent between boys and girls. However, by the end of puberty girls of average weight will have have a body composition of 24 to 30 per cent fat, while boys hardly change at all.

“There is a very spectacular stacking on of adipose tissue during those years, and of course that’s what makes women such a distinctive shape compared to men,” says Bainbridge. “Men have got the same as most animals, it’s women that are absolutely exceptional.”

March 16, 2015

Yes, men and women do have “conflicting strategies” in relationship-seeking

Filed under: Science — Tags: , — Nicholas @ 04:00

Amy Alkon responds to a recent Guardian piece lamenting men’s choices in (younger) women:

Evolutionary psychologists David Buss and David Schmitt theorized that men and women have “conflicting strategies” in seeking romantic partners, emerging from our differing physiologies and the ensuing differences in what sex can cost us.

Because a woman can get pregnant from a single sex act and be stuck with a kid to drag around and feed, women evolved to care a lot less about a man’s looks than his ability and willingness to be a “provider.” A veritable mountain of research suggests Buss and Schmitt’s theory is right.

For example, anthropologist John Marshall Townsend and psychologist Gary Levy showed women photos of an ugly guy in a Rolex and business attire and a handsome guy in a Burger King uniform. Women overwhelmingly went for the business lizard over the burger stud.

But back to the guys. Ancestral men could just walk away after sex and still pass on their genes. So men evolved to want to have sex with as many of the most healthy, fertile women they could. And what does health and fertility look like? Well, female beauty: Youth, clear skin, symmetrical features (reflecting health and no icky parasites); long, shiny hair; and a figure that’s more hourglass than beer vat.

The difference in what men and women prioritize in partners is best summed up by my friend Walter Moore. A guy complained to him that women are only attracted to wealthy men. Walter joked back, “That’s so unfair because we don’t expect them to be wealthy; all we ask is that they look like models.”

February 26, 2015

Humanity’s not-so-distant cousins

Filed under: History, Science — Tags: , — Nicholas @ 05:00

Real Clear Science has an excerpt from Yuval Harari’s recent book Sapiens: A Brief History of Humankind:

Scientists also agree that about 70,000 years ago, Sapiens from East Africa spread into the Arabian peninsula, and from there they quickly overran the entire Eurasian landmass.

When Homo sapiens landed in Arabia, most of Eurasia was already settled by other humans. What happened to them? There are two conflicting theories. The ‘Interbreeding Theory’ tells a story of attraction, sex and mingling. As the African immigrants spread around the world, they bred with other human populations, and people today are the outcome of this interbreeding.

For example, when Sapiens reached the Middle East and Europe, they encountered the Neanderthals. These humans were more muscular than Sapiens, had larger brains, and were better adapted to cold climes. They used tools and fire, were good hunters, and apparently took care of their sick and infirm. (Archaeologists have discovered the bones of Neanderthals who lived for many years with severe physical handicaps, evidence that they were cared for by their relatives.) Neanderthals are often depicted in caricatures as the archetypical brutish and stupid ‘cave people’, but recent evidence has changed their image.

According to the Interbreeding Theory, when Sapiens spread into Neanderthal lands, Sapiens bred with Neanderthals until the two populations merged. If this is the case, then today’s Eurasians are not pure Sapiens. They are a mixture of Sapiens and Neanderthals. Similarly, when Sapiens reached East Asia, they interbred with the local Erectus, so the Chinese and Koreans are a mixture of Sapiens and Erectus.

The opposing view, called the ‘Replacement Theory’ tells a very different story – one of incompatibility, revulsion, and perhaps even genocide. According to this theory, Sapiens and other humans had different anatomies, and most likely different mating habits and even body odours. They would have had little sexual interest in one another. And even if a Neanderthal Romeo and a Sapiens Juliet fell in love, they could not produce fertile children, because the genetic gulf separating the two populations was already unbridgeable. The two populations remained completely distinct, and when the Neanderthals died out, or were killed off, their genes died with them. According to this view, Sapiens replaced all the previous human populations without merging with them. If that is the case, the lineages of all contemporary humans can be traced back, exclusively, to East Africa, 70,000 years ago. We are all ‘pure Sapiens’.

A lot hinges on this debate. From an evolutionary perspective, 70,000 years is a relatively short interval. If the Replacement Theory is correct, all living humans have roughly the same genetic baggage, and racial distinctions among them are negligible. But if the Interbreeding Theory is right, there might well be genetic differences between Africans, Europeans and Asians that go back hundreds of thousands of years. This is political dynamite, which could provide material for explosive racial theories.

In recent decades the Replacement Theory has been the common wisdom in the field. It had firmer archaeological backing, and was more politically correct (scientists had no desire to open up the Pandora’s box of racism by claiming significant genetic diversity among modern human populations). But that ended in 2010, when the results of a four-year effort to map the Neanderthal genome were published. Geneticists were able to collect enough intact Neanderthal DNA from fossils to make a broad comparison between it and the DNA of contemporary humans. The results stunned the scientific community.

It turned out that 1-4 per cent of the unique human DNA of modern populations in the Middle East and Europe is Neanderthal DNA. That’s not a huge amount, but it’s significant. A second shock came several months later, when DNA extracted from the fossilised finger from Denisova was mapped. The results proved that up to 6 per cent of the unique human DNA of modern Melanesians and Aboriginal Australians is Denisovan DNA.

January 17, 2015

QotD: “Radicalizing the Romanceless”

Filed under: Politics, Quotations — Tags: , , , , — Nicholas @ 01:00

Barry is using my second-favorite rhetorical device, apophasis, the practice of bringing up something by denying that it will be brought up. For example, “I think the American people deserve a clean debate, and that’s why I’m going to stick to the issues, rather than talking about the incident last April when my opponent was caught having sex with a goat. Anyway, let’s start with the tax rate…”

He is complaining about being single by saying that you can’t complain about being single – and, as a bonus, placating feminists by blaming the whole thing on the manosphere as a signal that he’s part of their tribe and so should not be hurt.

It almost worked. He only got one comment saying he was privileged and entitled (which he dismisses as hopefully a troll). But he did get some other comments that remind me of two of my other least favorite responses to “nice guys”.

First: “Nice guys don’t want love! They just want sex!”

One line disproof: if they wanted sex, they’d give a prostitute a couple bucks instead of spiralling into a giant depression.

Second: “You can’t compare this to, like, poor people who complain about being poor. Food and stuff are basic biological human needs! Sex isn’t essential for life! It’s an extra, like having a yacht, or a pet tiger!”

I know that feminists are not always the biggest fans of evolutionary psychology. But I feel like it takes a special level of unfamiliarity with the discipline to ask “Sure, evolution gave us an innate desire for material goods, but why would it give us an deep innate desire for pair-bonding and reproduction??!”

But maybe a less sarcastic response would be to point out Harry Harlow’s monkey studies. These studies – many of them so spectacularly unethical that they helped kickstart the modern lab-animals’-rights movement – included one in which monkeys were separated from their real mother and given a choice between two artifical “mothers” – a monkey-shaped piece of wire that provided milk but was cold and hard to the touch, and a soft cuddly cloth mother that provided no milk. The monkeys ended up “attaching” to the cloth mother and not the milk mother.

In other words – words that shouldn’t be surprising to anyone who has spent much time in a human body – companionship and warmth can be in some situations just as important as food and getting your more basic needs met. Friendship can meet some of that need, but for a lot of people it’s just not enough.

When your position commits you to saying “Love isn’t important to humans and we should demand people stop caring about whether or not they have it,” you need to take a really careful look in the mirror – assuming you even show up in one.

Scott Alexander, “Radicalizing the Romanceless”, Slate Star Codex, 2014-08-31.

December 27, 2014

ESR on the origins of open source theory

Filed under: History, Technology — Tags: , , , , — Nicholas @ 03:00

Eric S. Raymond acknowledges the strong influence of evolutionary psychology on the development of open source theory:

Yesterday I realized, quite a few years after I should have, that I have never identified in public where I got the seed of the idea that I developed into the modern economic theory of open-source software – that is, how open-source “altruism” could be explained as an emergent result of selfish incentives felt by individuals. So here is some credit where credit is due.

Now, in general it should be obvious that I owed a huge debt to thinkers in the classical-liberal tradition, from Adam Smith down to F. A. Hayek and Ayn Rand. The really clueful might also notice some connection to Robert Trivers’s theory of reciprocal altruism under natural selection and Robert Axelrod’s work on tit-for-tat interactions and the evolution of cooperation.

These were all significant; they gave me the conceptual toolkit I could apply successfully once I’d had my initial insight. But there’s a missing piece – where my initial breakthrough insight came from, the moment when I realized I could apply all those tools.

The seed was in the seminal 1992 anthology The Adapted Mind: Evolutionary Psychology and the Generation of Culture. That was full of brilliant work; it laid the foundations of evolutionary psychology and is still worth a read.

(I note as an interesting aside that reading science fiction did an excellent job of preparing me for the central ideas of evolutionary psychology. What we might call “hard adaptationism” – the search for explanations of social behavior in evolution under selection – has been a central theme in SF since the 1940s, well before even the first wave of academic sociobiological thinking in the early 1970s and, I suspect, strongly influencing that wave. It is implicit in, as a leading example, much of Robert Heinlein’s work.)

The specific paper that changed my life was this one: Two Nonhuman Primate Models for the Evolution of Human Food Sharing: Chimpanzees and Callitrichids by W.C. McGrew and Anna T.C. Feistner.

In it, the authors explained food sharing as a hedge against variance. Basically, foods that can be gathered reliably were not shared; high-value food that could only be obtained unreliably was shared.

The authors went on to observe that in human hunter-gatherer cultures a similar pattern obtains: gathered foods (for which the calorie/nutrient value is a smooth function of effort invested) are not typically shared, whereas hunted foods (high variance of outcome in relation to effort) are shared. Reciprocal altruism is a hedge against uncertainty of outcomes.

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