Showing posts with label genetics. Show all posts
Showing posts with label genetics. Show all posts

July 9, 2010

Chinese science, technology, and IQ

From the Washington Post last week:
China pushing the envelope on science, and sometimes ethics
By John Pomfret

SHENZHEN, CHINA -- Last year, Zhao Bowen was part of a team that cracked the genetic code of the cucumber. These days, he's probing the genetic basis for human IQ.

Zhao is 17.

Centuries after it led the world in technological prowess -- think gunpowder, irrigation and the printed word -- China has barged back into the ranks of the great powers in science. With the brashness of a teenager, in some cases literally, China's scientists and inventors are driving a resurgence in potentially world-changing research.

Unburdened by social and legal constraints common in the West, China's trailblazing scientists are also pushing the limits of ethics and principle as they create a new -- and to many, worrisome -- Wild West in the Far East.

A decade ago, no one considered China a scientific competitor. Its best and brightest agreed and fled China in a massive brain drain to university research labs at Harvard, Stanford and MIT.

But over the past five years, Western-educated scientists and gutsy entrepreneurs have conducted a rearguard action, battling China's hidebound bureaucracy to establish research institutes and companies. Those have lured home scores [i..e., at least 40] of Western-trained Chinese researchers dedicated to transforming the People's Republic of China into a scientific superpower.

"They have grown so fast and so suddenly that people are still skeptical," said Rasmus Nielsen, a geneticist at the University of California at Berkeley who collaborates with Chinese counterparts. "But we should get used to it. There is competition from China now, and it's really quite drastic how things have changed."

... China has jumped to second place -- up from 14th in 1995 -- behind the United States in the number of research articles published in scientific and technical journals worldwide.

Backed by the Bill and Melinda Gates Foundation, Chinese medical researchers, partnering with a firm in the United States, beat out an Indian team last year to develop a new test for cervical cancer that costs less than $5. The goal is to test 10 million Chinese women within three years. ...

Meanwhile, Chinese military researchers appear to be on the cusp of a significant breakthrough: a land-based anti-ship ballistic missile that is causing concern within the U.S. Navy.

In 2007, Chinese geneticists discovered vast differences in the genetic makeup of Africans, Asians and Caucasians. They will soon report a breakthrough showing why some people -- such as Tibetans -- can live effortlessly at high altitudes while others can't.

There are challenges. China is still considered weak at innovation, and Chinese bureaucrats routinely mandate discoveries -- fantasy-world marching orders that Western scientists view as absurd.

In 2008, the Ministry of Science and Technology gave researchers two years to come up with 30 medicines ready for clinical trials and only five days to apply for grants to fund the work. That's despite the fact that since the communist revolution in 1949, China has developed only one internationally recognized drug -- Artemisinin -- to fight malaria.

Chinese science and technology is also awash in scams and sometimes-troubling practices. More than 200 institutions in China practice controversial stem cell therapies for people suffering from injuries, diseases or birth defects. Although the government moved last year to regulate the industry, none of the techniques has been subjected to rigorous clinical trials.

China is also the leading source of what are known as "junk" patents -- ridiculous claims of "inventions" that are little more than snake-oil scams.

"This discovery is going to shake the world!" bellowed Liu Jian, chief executive of Hualong Fertilizer Technique Co. Liu says he has developed a method to reduce fertilizer use by half through the use of nanotechnology, although officials at the Agriculture Ministry mock the claim. "Will you help us raise some capital?" Liu asked in an interview.

Finally, plagiarism and doctored results seem to be as common as chopsticks. A study by Wuhan University uncovered an entire industry of bogus report and thesis writers who raked in $145 million last year, a fivefold increase since 2007.

The emergence of China as a nascent scientific superpower raises questions about the U.S. relationship with Beijing. Ever since the United States opened the door to Chinese students in the 1970s, hundreds of thousands have flocked to America. Most have studied science or engineering and have been welcomed in research institutions across the land. But with China becoming a competitor, U.S. experts have begun to question that practice.

FBI officials allege that there is a large-scale operation in the United States to pilfer American industrial, scientific, technological and military secrets. In the past few years, dozens of Chinese have been convicted of stealing American technology and shipping it to China.

"The science and technology relationship with China has always stood up against all kinds of political pressures," said Richard P. Suttmeier, who has researched China's rise for the National Science Foundation. "Now that you have competition going on, finding the basis for cooperation in the absence of trust is an issue. It goes to questions of espionage and a hunger for technology."

That hunger is evident in the halls of BGI, home to Zhao Bowen and more than 1,500 other Chinese scientists and technicians. Located in an industrial zone in the southern Chinese megalopolis of Shenzhen, BGI has grown into one of the world's leading genomics institutes devoted to deciphering the genetic blueprint of organisms.

Over the past few years, scientists at BGI sequenced the genes of a chicken, a silkworm, a panda, a strain of rice and 4,000-year-old human remains from Greenland.

In January, BGI made the biggest purchase of genome sequencing equipment ever, buying 128 ultra-high-tech machines from California-based Illumina. With that one acquisition, BGI could very well surpass the entire gene-sequencing output of the United States.

Inside the 11-story facility, the vibe is pure Silicon Valley start-up: shorts, flip-flops, ankle bracelets, designer eyewear and a random tattoo. Zhao came to BGI on a summer internship last year to work on cucumbers. Now a full-time employee while continuing his studies, Zhao is turning his attention to a topic Western researchers have shied away from because of ethical worries: Zhao plans to study the genes of 1,000 of his best-performing classmates at a top high school in Beijing and compare them, he said, "with 1,000 normal kids."

July 2, 2010

Political Evolution in Tibet

Nick Wade writes in the NY Times:
Tibetans live at altitudes of 13,000 feet, breathing air that has 40 percent less oxygen than is available at sea level, yet suffer very little mountain sickness. The reason, according to a team of biologists in China, is human evolution, in what may be the most recent and fastest instance detected so far.

Comparing the genomes of Tibetans and Han Chinese, the majority ethnic group in China, the biologists found that at least 30 genes had undergone evolutionary change in the Tibetans as they adapted to life on the high plateau. Tibetans and Han Chinese split apart as recently as 3,000 years ago, say the biologists, a group at the Beijing Genomics Institute led by Xin Yi and Jian Wang. The report appears in Friday’s issue of Science.
 
If confirmed, this would be the most recent known example of human evolutionary change. Until now, the most recent such change was the spread of lactose tolerance — the ability to digest milk in adulthood — among northern Europeans about 7,500 years ago. But archaeologists say that the Tibetan plateau was inhabited much earlier than 3,000 years ago and that the geneticists’ date is incorrect.

When lowlanders try to live at high altitudes, their blood thickens as the body tries to counteract the low oxygen levels by churning out more red blood cells. This overproduction of red blood cells leads to chronic mountain sickness and to lesser fertility — Han Chinese living in Tibet have three times the infant mortality of Tibetans.

... The biologists found about 30 genes in which a version rare among the Han had become common among the Tibetans. The most striking instance was a version of a gene possessed by 9 percent of Han but 87 percent of Tibetans.

Such an enormous difference indicates that the version typical among Tibetans is being strongly favored by natural selection. In other words, its owners are evidently leaving more children than those with different versions of the gene.

The gene in question is known as hypoxia-inducible factor 2-alpha, or HIF2a, and the Tibetans with the favored version have fewer red blood cells and hence less hemoglobin in their blood.

The finding explains why Tibetans do not get mountain sickness but raises the question of how they compensate for the lack of oxygen if not by making extra red blood cells.

... Genetic differences between Tibetans and Chinese are a potentially delicate issue, given Tibetan aspirations for political autonomy. Dr. Nielsen said he hoped that the Beijing team’s results would carry no political implications, given that it is cultural history and language, not genetics, that constitute a people. There is not much genetic difference between Danes and Swedes, he added, but Denmark and Sweden are separate countries.
 
Well, it's a little more complicated than that. The Chinese government is encouraging Han Chinese to flood into Tibet and demographically overwhelm Tibetans. Is this strategy doomed by the Han's genetic lack of adaptation for living and reproducing at roughly the top of Pike's Peak? Or do these new findings hold out hope to the Chinese government that they could start a program to genetically screen potential Han colonists to find the small percentage with the right gene variants to thrive and reproduce in Tibet? After all, there are a lot of Han to choose among.

July 1, 2010

Guardian: Lower IQs found in disease-rife countries, scientists claim

From The Guardian:
Lower IQs found in disease-rife countries, scientists claim
Energy can be diverted away from brain development to fight infection, explaining 'lower intelligence in warmer countries'
People who live in countries where disease is rife may have lower IQs because they have to divert energy away from brain development to fight infections, scientists in the US claim.
The controversial idea might help explain why national IQ scores differ around the world, and are lower in some warmer countries where debilitating parasites such as malaria are widespread, they say.

Researchers behind the theory claim the impact of disease on IQ scores has been under-appreciated, and believe it ranks alongside education and wealth as a major factor that influences cognitive ability.

Attempts to measure intelligence around the world are fraught with difficulty and many researchers doubt that IQ tests are a suitable tool for the job. The average intelligence of a nation is likely to be governed by a complex web of interwoven factors.

The latest theory, put forward by Randy Thornhill and others at the University of New Mexico, adds disease to a long list of environmental and other issues that may all play a role in determining intelligence. Thornhill made the news in 2000, when he coauthored a provocative book called A Natural History of Rape in which he argues that sexual coercion emerged as an evolutionary adaptation.

Writing in the journal, Proceedings of the Royal Society, Thornhill and his colleagues explain that children under five devote much of their energy to brain development. When the body has to fight infections, it may have to sacrifice brain development, they say.

In the American South, for example, hookworm, an energy-sapping infection that can cause cognitive impairment, was a giant problem until John D. Rockefeller funded a campaign against it starting in 1909. Poor Southerners seemed to have a lot more pep, physical and mental, once they started wearing shoes and taking other steps to avoid hookworm.

Hookworm is still a big problem in some of the warm-weather parts of the world. I'm sure there are other nasty parasites, and they tend to be more common in the tropics.

As Greg Cochran and Paul Ewald pointed out in the 1990s, there are probably numerous chronic infections that don't attract as much attention as major acute ones, but do often add up to trouble. A lot of things in the modern world, such as clean tap water, probably diminish their impact. Little kids get a lot of antibiotics these days for acute infections like earaches. The antibiotics might be killing off low-level infections at the same time. Who knows?

Likewise, Darwinian selection under conditions of heavy infectious disease burden will tend to be oriented toward improving the immune system more than raising intelligence, which will tend to have long term effects on tropical populations.
To test the idea, Thornhill's group used three published surveys of global IQ scores and compared them with data from the World Health Organisation (WHO) on how badly infectious diseases affect different countries. The list included common infections, such as malaria, tetanus and tuberculosis.

The scientists found that the level of infectious disease in a country was closely linked to the average national IQ. The heavier the burden of disease, the lower the nation's IQ scores. Thornhill believes that nations who have lived with diseases for long periods may have adapted, by developing better immune systems at the expense of brain function.

"The effect of infectious disease on IQ is bigger than any other single factor we looked at," said Chris Eppig, lead author on the paper. "Disease is a major sap on the body's energy, and the brain takes a lot of energy to build. If you don't have enough, you can't do it properly."

"The consequence of this, if we're right, is that the IQ of a nation will be largely unaffected until you can lift the burden of disease," Eppig added.

"It's an interesting and provocative finding," said Geraint Rees, director of the UCL Institute of Cognitive Neuroscience. "It explains about 50 to 60% of the variability in IQ scores and appears to be independent of some other factors such as overall GDP."

"The authors suggest that more infectious disease could lead to lower IQ scores through an impact on brain development. This is an interesting speculation, but the data don't prove it one way or the other," he said. "A bigger problem is that it might be driven by a third factor, that affects both infectious disease prevalence and IQ test scores."

Right. Multicollinearity is always a problem with correlation studies, and this topic especially: are lower IQs in the tropics caused by tropical diseases or by the tropics that cause the tropical diseases themselves?

For example, I've long hypothesized that one general problem that brains need to deal with is shedding heat and that is of course a bigger problem in the tropical than the temperate world. 

How to dissipate heat generated by computer chips is a huge issue in computer design. As I type on my laptop computer, the surface of the machine that is touching my wrists is about 100 degrees F. The bottom of my laptop must be 150 degrees or more. A fan is running full speed to shed heat to keep the CPU chip from melting. My office is heating up from the combination of my PC and myself, both working hard. I have just now opened my window to disperse the heat. It is a cool evening here, so the temperature is palpably dropping by the minute. If I was in a tropical climate, I'd need to turn on the air conditioning or start the fan or whatever.

Intel had driven up the power of CPU chips largely by increasing the clock speed, but when they hit four gigahertz, Intel found that chips were melting down. So, Intel  had to revamp massively and find other way to follow Moore's Law, such as multiple cores.

Similarly, your brain generates more heat when you are thinking hard than when it is idling.

Not surprisingly, skull shapes seem to be somewhat related to heat dissipation problems. Eskimos have round heads to conserve heat, while Kenyan marathoners tend to have narrow heads with a lot of surface area that dissipate heat more easily.
For reasons that are unclear, IQ scores are generally rising around the world. Thornhill suggests monitoring rates of infectious diseases in nations as they develop, to see if they decline and IQ tests scores rise.

Singapore would seem to be an example of a tropical place where public hygiene, antibiotics, air conditioning, education, and so forth combine in a virtuous circle.
Richard Lynn, professor of psychology at Ulster University, and author of the 2002 book, IQ and the Wealth of Nations, said disease and IQ is a two-way relationship, with low national IQs being partly responsible for widespread infectious diseases.

Right, it's hard to get started turning, say, Equatorial Guinea into Singapore without Singaporeans to get you started.

Here's the abstract of Thornhill's paper:
In this study, we hypothesize that the worldwide distribution of cognitive ability is determined in part by variation in the intensity of infectious diseases. From an energetics standpoint, a developing human will have difficulty building a brain and fighting off infectious diseases at the same time, as both are very metabolically costly tasks. Using three measures of average national intelligence quotient (IQ), we found that the zero-order correlation between average IQ and parasite stress ranges from r = −0.76 to r = −0.82 (p < 0.0001). These correlations are robust worldwide, as well as within five of six world regions. Infectious disease remains the most powerful predictor of average national IQ when temperature, distance from Africa, gross domestic product per capita and several measures of education are controlled for. These findings suggest that the Flynn effect may be caused in part by the decrease in the intensity of infectious diseases as nations develop.

Afghanistan would be the leading example of a cold winter place that seems pretty dim, perhaps due to disease burden. It's second in the world in infant mortality. (The rest of the Worst 20 are black African countries, while Afghans are, as Daniel Dravot notes in the Man Who Would Be King, a bunch of more or less white people. But how did that Civilizing Mission thing work out for you, Danny boy?)

James Michener's 1963 novel about Afghanistan, Caravans, has an Afghan leader arguing, with some pride, that while children die like flies in Afghanistan, if they survive past childhood, they grow up to be tough, mean bastards with well-tuned immune systems.

But, it's stupid of Afghans to have so much disease burden. So, I'm not sure that says much about causality. Are they so knuckleheaded because they are sick so much, or are they sick so much because they are so knuckleheaded?

But, even when it proves hard to determine ultimate causation from correlation studies, correlation itself is worth knowing. The general rule is that, as Kingsley Amis said in Lucky Jim: "There was no end to the ways in which nice things are nicer than nasty ones."

June 10, 2010

More on Jewish genetics

Nicholas Wade of the NYT lucidly describes some of the results from the two new Jewish genetics study (one of which you can read here):
The shared genetic elements suggest that members of any Jewish community are related to one another as closely as are fourth or fifth cousins in a large population, which is about 10 times higher than the relationship between two people chosen at random off the streets of New York City, Dr. Atzmon said. 

Race is all about who your relatives are, and, not coincidentally, answers to the question of who you are related to turn out to be unavoidably relativistic.

Unfortunately, human beings don't deal well cognitively with things that are inherently relative. People are good at noticing that A is more likely than B, but they aren't good at formally reasoning about this relativistic comparison. Some will say that A is always true, while others will smugly attempt to disprove that "A is more likely than B" by pointing out exceptions in which B is true, as if the exception disproves the tendency.
Ashkenazic and Sephardic Jews have roughly 30 percent European ancestry, with most of the rest from the Middle East, the two surveys find. The two communities seem very similar to each other genetically, which is unexpected because they have been separated for so long.

One explanation is that they come from the same Jewish source population in Europe. The Atzmon-Ostrer team found that the genomic signature of Ashkenazim and Sephardim was very similar to that of Italian Jews, suggesting that an ancient population in northern Italy of Jews intermarried with Italians could have been the common origin. The Ashkenazim first appear in Northern Europe around A.D. 800, but historians suspect that they arrived there from Italy.

April 27, 2010

Genetic Relativism

Carl Zimmer writes in the NYT in "The Search for Genes Leads to Unexpected Places:"
Edward M. Marcotte is looking for drugs that can kill tumors by stopping blood vessel growth, and he and his colleagues at the University of Texas at Austin recently found some good targets — five human genes that are essential for that growth. Now they’re hunting for drugs that can stop those genes from working. Strangely, though, Dr. Marcotte did not discover the new genes in the human genome, nor in lab mice or even fruit flies. He and his colleagues found the genes in yeast.  

I pointed out that in terms of genetic similarity, humanity and yeast weren't really all that different in a National Review article in 1999, "Chimps and Chumps," one of the earlier expressions of my constant theme of "genetic relativism:"
Ms. [Natalie] Angier hopes future studies prove we are more closely related to bonobos than to common chimps. Even Richard Wrangham and Dale Peterson, the dour authors of "Demonic Males: Apes and the Origins of Human Violence" ask, "Those loving bonobos -- did we pick the wrong primate to evolve from?" Dr. De Waal asserts that the news about the bonobo lifestyle "commands attention because the bonobo shares more than 98 percent of our genetic profile … making it as close to a human as, say, a fox is to a dog. The split between the human line of ancestry and the line of the chimpanzee and the bonobo is believed to have occurred a mere eight million years ago." ...

Fifth, the oft-cited 98% figure for shared DNA is less impressive than it looks. Most DNA is unused, so natural selection never changes it. Another big chunk of your personal DNA controls the basics of earthly carbon-based life, and is extremely common across multitudinous organisms. Thus, one study found we share 70% of our DNA with yeast! Perhaps if you don't have a great ape around, you can scrape by letting a packet of Fleischmann's Quick-Rise pinch-hit as your role model. De Waal's statement that a chimp is as genetically similar to a human as a fox is to a dog may be true, but it should remind us of the striking number of gene-driven differences seen merely among dog breeds. A collie is identical to a pit bull in all but a tiny fraction of its genes, yet the two breeds differ radically in size, shape, behavior, mentality, and personality. Small genetic differences can have big consequences.

On the other hand, a collie and a pit bull are more similar to each other than they are to, say, an octopus. And a collie and an octopus would be more genetically similar to each other than to, say, copper-based lifeforms on Epsilon Eridani IV.

The question: "Is X similar to or different from Y?" is extremely relativistic.

And that's true for races, siblings, even identical twins, who might differ in, say, a half-dozen genes due to copying errors, along with other types of non-genetic differences. 

When you study examples of twins, you notice that there are often consistent differences between them. For example, a glance at the basketball statistics of the 1970s All-Stars Dick and Tom Van Arsdale shows that Dick was consistently a little bit better than Tom over their 12 year NBA careers. For example, to take the most context-independent statistic, Dick made .790 of his freethrows, while Tom made .762. Dick shot .464 on two pointers, while Tom shot .433. Dick averaged 34.5 minutes per game over his career while Tom averaged 30.9 minutes. (In their high school class, Dick was the valedictorian, while Tom had the third highest GPA.)

The differences between Dick and Tom were relevant to NBA general managers. For instance, Dick was drafted 10th in the 1965 NBA draft, while Tom was drafted 11th, which, looking back on their long careers, was the correct order.

On the other hand, in a lot of ways, Dick and Tom Van Arsdale were awfully similar.

I apply the same relativistic framework for thinking about more contentious issues, such as race. My basic approach is to make sure I'm right by pointing out the tautological nature of all questions about similarities and differences: "It depends upon what you want to know." When you keep that in mind at all times, it's not terribly hard to think accurately and insightfully. If you can figure out what the right question is, it's much easier to get the right answer.

Indeed, that's why I'm right about racial questions so much more frequently than other pundits. It's easy to figure things out if you have an intellectually sophisticated basis for your thinking. In contrast, the conventional wisdom is based on an embarrassingly crude mindset.
 

April 21, 2010

The Neanderthal in You

The idea has been kicking around for a number of years that modern humans may have picked up some valuable genes by mating with Neanderthals (kind of like Clan of the Cave Bear, that really odd series of romance novels set in caveman days that were huge bestsellers a generation ago).

A new study supports that theory. John Hawks has the background.

The idea is that if Neanderthals were off evolving by themselves in the frigid North for a few hundred thousand years, they likely would have developed some well-honed genes for dealing with the difficulties of life outside the tropics. The fastest way for modern humans migrating out of the tropics to acquire traits optimized for surviving winters, or whatever, would have been to interbreed with Neanderthals.

April 20, 2010

Clone of Contention

Should Bryan Caplan clone himself?

Julian Simon acolyte Bryan Caplan, an economist at George Mason U., wonders whether to include this paragraph in his upcoming book:
I confess that I take anti-cloning arguments personally.  Not only do they insult the identical twin sons I already have; they insult a son I hope I live to meet.  Yes, I wish to clone myself and raise the baby as my son.  Seriously.  I want to experience the sublime bond I'm sure we'd share.  I'm confident that he'd be delighted, too, because I would love to be raised by me.  I'm not pushing others to clone themselves.  I'm not asking anyone else to pay for my dream.  I just want government to leave me and the cloning business alone.  Is that too much to ask? 

Unfortunately, Professor Caplan doesn't inform us what his wife thinks about his desire to create a child untainted by her genes. Does Professor Caplan intend to have Mrs. Caplan bear his clone for him? Does Professor Caplan intend to have Mrs. Caplan pick up after his clone for 21 years? Will Mrs. Caplan appreciate it when she and her husband's immature clone get into an argument and Professor Caplan sides with his clone against his wife? Will she be concerned that he might favor his clone in his will over their mutual children?

Of course, that's assuming that Bryan's assumption that he and his clone would be Best Friends Forever is correct. More likely, the opposite would be true.

Generally speaking, people who would like to clone themselves tend to be arrogant and lacking in common sense. Their children will tend to also be arrogant and lacking in common sense. The interpersonal dynamics between cloner and clonee would likely be disastrous.
Are families in which the sons are exactly like the fathers happier? I don't see a lot of evidence for that. In fact, I see a lot of evidence from memoirs and fiction that strong-willed fathers tend to have strong-willed sons, and the two clash relentlessly over who will be dominant. Too much similarity does not always make for happiness within a family.

Of course, this whole cloning thing might be useful if a husband was trying to pawn some illegitimate kid he had with a stripper off on his wife to raise: "Hey, honey, sorry that I forgot to mention it, but I had myself cloned! Be a doll and clean up after little Me Jr. for the next 21 years." This might work on an exceptionally clueless wife.

That reminds me. Back in the 1990s, I pitched a screenplay to that old HBO comedy show about a sports agent, Arliss, in which one of Arliss's clients, a narcissistic gay Olympics superstar modeled on sprinter Carl Lewis, wants Arliss to arrange for his cloning:
Arliss is setting up a grudge match race between a Carl Lewis-style track superstar and his arch-rival, an extremely juiced-up looking Ben Johnson-type. Client Carl shows up, accompanied by his best friend / sister Carol. Carl says he isn't interested in reproducing the old-fashioned way, and asks Arliss to help him clone himself. Carol will carry the clone/fetus and raise the baby. Carol takes Arliss's secretary Rita aside to suggest that they try to get the cloning over and done with real fast. She breaks down and says it's a ruse she's putting over on Carl because she's pregnant -- with Ben Johnson's baby. Arliss asks Carl that in return for making the arrangement at a pet cloning clinic to get the clone signed up for a lifetime deal. But, Arliss is heartbroken when Rita breaks the truth to him.

In general, I have fewer problems with cloning in the abstract than I have deep doubts about the specific type of person (e.g., Bryan) who would want to get himself cloned.

April 7, 2010

What does it take to be a genius?

Here's the beginning of my new Taki's Magazine column:

What does it take to be a genius?

Europeans of the Romantic Era tended to ascribe the accomplishments of the great to an inborn spark. In contrast, in this age in which voracious competitiveness must rationalize itself in politically correct terms, American self-help books, such as Malcolm Gladwell’s Outliers and David Shenk’s The Genius in All of Us, denigrate the importance of talent. They even go to the comic extreme of citing Mozart, who could compose music as fast as he could jot it down, as evidence for the dominance of nurture over nature.

To reach the pinnacles of achievement, to be, out of the 100 billion or so humans who have ever lived, one of the few hundred individuals to be remembered by one name—to be a Mozart, a Beethoven, a Bach—does it help to have innate talent? How about ten thousand hours of practice? An intense work ethic? An obsessive personality? A supportive family? A conducive culture? Role models? Personal connections? Energy? Being in the right place at the right time? Not dying before adulthood? Sheer luck?

Yes.

Few of the all-time greats were fortunate enough to have every single one of these factors in abundance, but they typically had more than a few. Nobody can accomplish all that solely on his own. Conversely, no family, culture, or state can concoct a genius without a unique individual. ...

And, yet, the notion that golden age German-speakers enjoyed some genetic advantages in musical talent is not implausible. Why?

Read the whole thing there and comment upon it below.

My published articles are archived at iSteve.com -- Steve Sailer

March 24, 2010

For my Finnish readers

On a per capita basis, I seem to have more Finnish readers than American ones. From a press release by the Institute for Molecular Medicine Finland:

The Institute for Molecular Medicine Finland (FIMM) together with its collaborators has compiled the Finnish Gene Atlas, which contains genome-wide gene marker data for more than 40,000 Finns. The first findings obtained with this collection, which is exceptionally extensive for Europe, pertain to determination of the origin of Finns.

Hundreds of thousands of gene markers make it possible to examine similarities in the genetic architecture of Finns and other European peoples. Use of the Atlas has revealed, for instance, that:

  • Finns are unique on the genetic map of Europe; we differ considerably both from Central Europeans and from our neighbours to the east.
  • Genetically, Finns have more in common with, for example, the Dutch or Russians living in the area of Murom, to the east of Moscow, than with our linguistic relations, the Hungarians; genetic closeness clearly follows geographic distance more closely than linguistic distance.
  • Owing to our settlement history, the genetic differences among Finns are great on both the east/west and north/south axes; the greater the geographic distance is, the greater the genetic differences are. In comparing the Finnish dialect areas, the greatest genetic differences are found between Finns of Southwest Finland and inhabitants of Kuusamo in Northeast Finland.
  • The linguistic link between Swedish-speaking Finns living in coastal areas and Swedes is also reflected in the greater genetic closeness of these two groups in comparison with Finnish speakers.
During 2010 the Finnish Gene Atlas will be supplemented with the first Finns whose whole genome will be fully sequenced.

My published articles are archived at iSteve.com -- Steve Sailer

March 3, 2010

NYT: "Human Culture, an Evolutionary Force"

NYT genetics reporter Nicholas Wade has a new article with the self-explanatory title "Human Culture, an Evolutionary Force," using good old lactose tolerance as an example. It features a picture of a beautiful Kenyan highland meadow that might make even me want to take up long distance running. (Kenyan herdsmen are sort of "horseless cowboys" who hunt down strays on foot, so distance running ability is a useful trait for them.)

One question is why favorable traits such as lactose tolerance often don't reach fixation.

My published articles are archived at iSteve.com -- Steve Sailer

January 20, 2010

Is facial recognition a non-g factor mental module?

Physicists are not particularly well known for never forgetting a face, while some politicians are. Physicists tend to have higher IQs than politicians, but politicians have probably been evolving longer. So, is facial recognition just the general factor of intelligence in action once again, or is there a specifically evolved cognitive mechanism for it?

One of the more intriguing epistemological questions of recent decades has been over the prevalence of a g or General Factor of intelligence versus specific "mental modules."

The dominance of the "blank slate" theory of social conditioning was undermined beginning in 1958 by linguist Noam Chomsky's observation that children seemed to be particularly good at learning and speaking their native tongue, better than the existing behaviorist / Pavlovian worldview would suggest, which implied that humans have what Steven Pinker called in 1994 a "language instinct."

Although Chomsky remained agnostic over whether natural selection could account for this instinct, a school of evolutionary psychology grew up late in the century, exemplified by John Tooby and Leda Cosmides's 1992 book, that hypothesized the existence of multitudinous inherited mental modules for skills besides language.

Psychometricians, such as Arthur Jensen and Chris Brand (in 1998 books both entitled The g Factor) suggested that the very old (Spearman 1904) concept of a general factor of intelligence could account for quite a bit of the hypothesized mental modules. This seems particularly likely for mental demands that people only recently encountered, such as understanding quantum mechanics. It seems implausible that humans evolved a specific mental module for, say the Physics BC Advanced Placement test. Instead, people seem to rely for that upon the general factor plus some specific factors such as three-dimensional imagination.

Therefore, evolutionary psychologists have tended to focus their hypothesizing on cognitive skills that would have been useful in navigating the social life of a low tech tribe, such as learning a language or recognizing faces.

From an MIT press release adapted in Science Daily:
Recognizing faces is an important social skill, but not all of us are equally good at it. Some people are unable to recognize even their closest friends (a condition called prosopagnosia), while others have a near-photographic memory for large numbers of faces. Now a twin study by collaborators at MIT and in Beijing shows that face recognition is heritable, and that it is inherited separately from general intelligence or IQ.

This finding plays into a long-standing debate on the nature of mind and intelligence. The prevailing generalist theory, upon which the concept of IQ is based, holds that if people are smart in one area they tend to be smart in other areas, so if you are good in math you are also more likely to be good at literature and history. IQ is strongly influenced by heredity, suggesting the existence of "generalist genes" for cognition.

Yet some cognitive abilities seem distinct from overall IQ, as happens when a person who is brilliant with numbers or music is tone-deaf socially or linguistically. Also, many specialized cognitive skills, including recognizing faces, appear to be localized to specialized brain regions. Such evidence supports a modularity hypothesis, in which the mind is like a Swiss Army knife -- a general-purpose tool with special-purpose devices.

"Our study provides the first evidence supporting the modularity hypothesis from a genetic perspective," said lead author Jia Liu, Professor of Cognitive Neuroscience at Beijing Normal University in China of the study published in the Jan. 7 issue of Current Biology. "That is, some cognitive abilities, like face recognition, are shaped by specialist genes rather than generalist genes."

"Our finding may help explain why we see such disparities of cognitive abilities within the same person in certain heritable disorders," added co-author Nancy Kanwisher of the McGovern Institute for Brain Research at MIT, where Liu studied before moving to Beijing. In dyslexia, for example, a person with normal IQ has deficits in reading, while in Williams Syndrome, people have low IQ but excellent language skills.

For the study, Liu and his colleagues recruited 102 pairs of identical twins and 71 pairs of fraternal twins aged 7 to 19 from Beijing schools. Because identical twins have 100 percent of their genes in common while fraternal twins have just 50 percent, traits that are strongly hereditary are more similar between identical twins than between fraternal twins. (Identical twins still show variability because of the influence of environmental factors.)

Participants were shown black-and-white images of 20 different faces on a computer screen for one second per image. They were then shown 10 of the original faces mixed with 20 new faces and asked which ones they had seen before. The scores were more closely matched between identical twins than fraternal twins, and Liu attributed 39 percent of the variance between individuals to genetic effects. Further tests confirmed that these differences were specific to face recognition, and did not reflect differences in sharpness of vision, general object recognition abilities, memory or other cognitive processes.

In an independent sample of 321 students, the researchers found that face recognition ability was not correlated with IQ, indicating that the genes that affect face recognition ability are distinct from those that affect IQ. Liu and Kanwisher are now investigating whether other cognitive abilities, such as language processing, understanding numbers, or navigation, are also heritable and independent from general intelligence and other cognitive abilities.

Generally speaking, language is so central to human thought that the ten question vocabulary test in the annual General Social Survey can be used as a rough proxy for IQ, so I don't think "language processing" is likely to pan out as heritable and terribly independent from general intelligence. There are presumably, however, specific language-related skills (such as, say, noticing when you are being insulted) that are less correlated with IQ than general language processing.

Even though vocabulary correlates closely with g, the Chomskyan idea of a language instinct seems fairly reasonable, since the vast majority of human beings who are not suffering an obvious organic problem (such as deafness or severe retardation) learn to speak a native tongue well enough to pass the famous Turing Test that has proven so difficult for artificial intelligence technologists.

In contrast, many other skills are much more widely distributed, such as singing on key.

Researchers at the Beijing Normal University and Graduate University of the Chinese Academy of Sciences contributed to this research: Qi Zhu, Yiying Song, Siyuan Hu, Xiaobai Li, Moqian Tian, Zonglei Zhen and Qi Dong.

In addition to providing new insight into the structure of the mind, this work could shed light on the underlying causes of developmental disorders like autism and dyslexia. "The heritability of these cognitively specific diseases suggests that some genes have specific cognitive effects, but it's a big mystery how genes produce cognitively specific effects," said Kanwisher.

Here's the abstract:
Heritability of the Specific Cognitive Ability of Face Perception

What makes one person socially insightful but mathematically challenged, and another musically gifted yet devoid of a sense of direction? Individual differences in general cognitive ability are thought to be mediated by “generalist genes” that affect many cognitive abilities similarly without specific genetic influences on particular cognitive abilities [1]. In contrast, we present here evidence for cognitive “specialist genes”: monozygotic twins are more similar than dizygotic twins in the specific cognitive ability of face perception. Each of three measures of face-specific processing was heritable, i.e., more correlated in monozygotic than dizygotic twins: face-specific recognition ability, the face-inversion effect [2], and the composite-face effect [3]. Crucially, this effect is due to the heritability of face processing in particular, not to a more general aspect of cognition such as IQ or global attention. Thus, individual differences in at least one specific mental talent are independently heritable. This finding raises the question of what other specific cognitive abilities are independently heritable and may elucidate the mechanisms by which heritable disorders like dyslexia and autism can have highly uneven cognitive profiles in which some mental processes can be selectively impaired while others remain unaffected or even selectively enhanced.

My published articles are archived at iSteve.com -- Steve Sailer

December 22, 2009

African-American admixture

Over the weekend, I started thinking about a 2002 article I wrote called "How White Are Blacks? How Black Are Whites?" about Penn State geneticist Mark D. Shriver's research that came up with an estimate of self-identified African Americans having 17% to 18% European admixture. I wondered: What's the latest on that number? The technology has certainly improved over the years.

Last May 22, Sarah A. Tishkoff of Penn published a paper in Science called "The Genetic Structure and History of Africans and African Americans." It featured a huge number of samples from within Africa, and a small number of African-Americans.

Anthro blogger Dienekes said:
The importance of this new paper from the Tishkoff Lab cannot be emphasized enough. It is probably the most comprehensive study of African genetic variation to date. The supplementary material (pdf) is itself 102 pages long and should keep you busy reading for a while (free for non-subscribers [the Science paper is not free, however]).

What this study has found in a nutshell is that "black" Africans belong to 14 distinct clusters. Black Americans belong overwhelmingly to the Niger-Kordofanian cluster [beginning mostly in Cameroon and Nigeria, and spreading broadly from their], consistent with their origin largely from Western Africa. ...

As I have stated many times before, Bantu speakers have recently expanded from their cradle and contributed genetically to almost all other Africans, while remaining relatively pure in their own homeland. [See p. 12 of Tishkoff's supplementary material.]

You hear a lot of stuff about how "Africans are the most genetically diverse population on earth, therefore, they have the most geniuses, etc." Malcolm Gladwell was trumpeting that argument way back in 1997 with his New Yorker article about "Why blacks are like boys and whites are like girls."

Unfortunately, this whole line of thought is based on a misunderstanding of what kind of genetic diversity population geneticists are interested in. You, me, and Malcolm Gladwell are interested in genes that affect IQ, sprinting skills, and the like. But population geneticists don't like to look at genes that do important things because those get altered over time by selection precisely because they are important. They like to look at genes that don't do much of anything, because they only change by random mutation, so they are the most useful for genealogical purposes.

The press release for Tishkoff's paper says:
A median proportion of European ancestry in African-Americans of 18.5 percent, with large variation among individuals.

Which is very similar to Shriver's work. Shriver had more crude technology but a larger sample of African-Americans from a couple of dozen areas, while Tishkoff has 365 drawn from Chicago, Pittsburgh, Baltimore, and North Carolina.

Yet, here's Tishkoff's abstract, which says Europeans make up about 13% of African-American genetic ancestry.
Africa is the source of all modern humans, but characterization of genetic variation and of relationships among populations across the continent has been enigmatic. We studied 121 African populations, four African American populations, and 60 non-African populations for patterns of variation at 1327 nuclear microsatellite and insertion/deletion markers. We identified 14 ancestral population clusters in Africa that correlate with self-described ethnicity and shared cultural and/or linguistic properties. We observed high levels of mixed ancestry in most populations, reflecting historical migration events across the continent. Our data also provide evidence for shared ancestry among geographically diverse hunter-gatherer populations (Khoesan speakers and Pygmies). The ancestry of African Americans is predominantly from Niger-Kordofanian (~71%), European (~13%), and other African (~8%) populations, although admixture levels varied considerably among individuals. This study helps tease apart the complex evolutionary history of Africans and African Americans, aiding both anthropological and genetic epidemiologic studies.

If you look at Table S6 on page 89 of 102 in her supplementary materials, you can see that her 13% figure apparently comes from a subsample of 98 African-Americans in four locations.

Interestingly, they come up with less than 1% of the genetic ancestry of African-Americans are American Indians but 5% are Asian Indian! Dienekes suggests that may be related to backflow from Out of Africa populations that went back In to Africa. Tishkoff says they are probably getting Asian Indians and Europeans confused in their analyses (they're basically all Caucasians), so the actual European admixture figure is likely higher and the actual Asian Indian figure lower:
Low levels of ancestry from several additional populations were also detected (Table S6): Fulani (means 0.0 - 0.03, individual range 0.00-0.14), Cushitic East African (means 0.02, individual range 0.05 - 0.10), Sandawe East African (means 0.01- 0.03, individual range 0.00 - 0.12), East Asian (means 0.01 – 0.02, individual range 0.0 - 0.08), and Indian (means 0.04 – 0.06, individual range 0.01 -0.17). The Fulani are present across West Africa and, therefore, would be expected to have contributed to the slave trade, and the Cushitic and Sandawe ancestry could represent slave trade originating from the east coast of Africa (S126). It should be noted that the levels of Indian ancestry in African Americans may be slightly overestimated, and the levels of European ancestry slightly underestimated, due to moderate levels of the Indian AAC in European/Middle Eastern individuals (Figs. 3 and 4). We did not observe significant levels of Native American ancestry. However, other regions of the US, may reveal Native American Ancestry, as previously reported (S125). Finally, European and African ancestry levels varied
considerably among individuals (Fig. 6).

Also, her Other African origins include some Saharan and Ethiopian groups that are somewhat Caucasian.

So, the 18.5% figure in the press release jibes fairly well with the supplementary materials if you add in the Asian Indians and some of the Northern Africans.

So, seven years later, Shriver's work is reasonably well confirmed.

By the way, Figure S28 shows Tishkoff's best guess for the origin of modern humans (the Atlantic coast of Namibia) and the Out of Africa exit point (half way up the Red Sea -- that may just be because there were two exit points, one at the Sinai and the other at Djibouti-Yemen, and their statistics are just splitting the difference).

Lots of interesting stuff in Tishkoff's paper on Pygmies, Bushmen, and others within Africa, but the African-American stuff is basically what I've been telling you all decade.

My published articles are archived at iSteve.com -- Steve Sailer

November 29, 2009

Geoffrey Miller: "The Looming Crisis in Human Genetics"

From The Economist:
The looming crisis in human genetics:
Some awkward news ahead
by Geoffrey Miller
Author of Spent

Human geneticists have reached a private crisis of conscience, and it will become public knowledge in 2010. The crisis has depressing health implications and alarming political ones. In a nutshell: the new genetics will reveal much less than hoped about how to cure disease, and much more than feared about human evolution and inequality, including genetic differences between classes, ethnicities and races.

About five years ago, genetics researchers became excited about new methods for “genome-wide association studies” (GWAS). We already knew from twin, family and adoption studies that all human traits are heritable: genetic differences explain much of the variation between individuals. We knew the genes were there; we just had to find them....

In 2010, GWAS fever will reach its peak. Dozens of papers will report specific genes associated with almost every imaginable trait—intelligence, personality, religiosity, sexuality, longevity, economic risk-taking, consumer preferences, leisure interests and political attitudes. The data are already collected, with DNA samples from large populations already measured for these traits. It’s just a matter of doing the statistics and writing up the papers for Nature Genetics. ...

GWAS researchers will, in public, continue trumpeting their successes to science journalists and Science magazine. They will reassure Big Pharma and the grant agencies that GWAS will identify the genes that explain most of the variation in heart disease, cancer, obesity, depression, schizophrenia, Alzheimer’s and ageing itself. ...

In private, though, the more thoughtful GWAS researchers are troubled. They hold small, discreet conferences on the “missing heritability” problem: if all these human traits are heritable, why are GWAS studies failing so often? ...

But the genes typically do not replicate across studies. Even when they do replicate, they never explain more than a tiny fraction of any interesting trait. In fact, classical Mendelian genetics based on family studies has identified far more disease-risk genes with larger effects than GWAS research has so far.

Why the failure? The missing heritability may reflect limitations of DNA-chip design: GWAS methods so far focus on relatively common genetic variants in regions of DNA that code for proteins. They under-sample rare variants and DNA regions translated into non-coding RNA, which seems to orchestrate most organic development in vertebrates. Or it may be that thousands of small mutations disrupt body and brain in different ways in different populations. At worst, each human trait may depend on hundreds of thousands of genetic variants that add up through gene-expression patterns of mind-numbing complexity.

Political science

We will know much more when it becomes possible to do cheap “resequencing”—which is really just “sequencing” a wider variety of individuals beyond the handful analysed for the Human Genome Project. Full sequencing means analysing all 3 billion base pairs of an individual’s DNA rather than just a sample of 1m genetic variants as the DNA chips do. When sequencing costs drop within a few years below $1,000 per genome, researchers in Europe, China and India will start huge projects with vast sample sizes, sophisticated bioinformatics, diverse trait measures and detailed family structures. (American bioscience will prove too politically squeamish to fund such studies.) The missing heritability problem will surely be solved sooner or later.

Or will it? At present, we understand the genetics of lactose tolerance fairly well because they are simple. We don't understand the genetics of IQ at all well, presumably because they are complicated. It would be interesting to know what are traits are the most promising targets intermediate in complexity between lactose tolerance and IQ.

The trouble is, the resequencing data will reveal much more about human evolutionary history and ethnic differences than they will about disease genes.

As Matt Ridley once said, your genes didn't evolve to kill you.

Once enough DNA is analysed around the world, science will have a panoramic view of human genetic variation across races, ethnicities and regions. We will start reconstructing a detailed family tree that links all living humans, discovering many surprises about mis-attributed paternity and covert mating between classes, castes, regions and ethnicities.

We will also identify the many genes that create physical and mental differences across populations, and we will be able to estimate when those genes arose. Some of those differences probably occurred very recently, within recorded history. Gregory Cochran and Henry Harpending argued in “The 10,000 Year Explosion” that some human groups experienced a vastly accelerated rate of evolutionary change within the past few thousand years, benefiting from the new genetic diversity created within far larger populations, and in response to the new survival, social and reproductive challenges of agriculture, cities, divisions of labour and social classes. Others did not experience these changes until the past few hundred years when they were subject to contact, colonisation and, all too often, extermination.

If the shift from GWAS to sequencing studies finds evidence of such politically awkward and morally perplexing facts, we can expect the usual range of ideological reactions, including nationalistic retro-racism from conservatives and outraged denial from blank-slate liberals. The few who really understand the genetics will gain a more enlightened, live-and-let-live recognition of the biodiversity within our extraordinary species—including a clearer view of likely comparative advantages between the world’s different economies.

More likely, we just won't hear much about it. For years, I've been hearing that as the evidence piles up, the dominant ideology will have to adapt to it. Why? Why not just lie more and persecute more? A lot of people find covering up the truth to be more emotionally satisfying than learning it.

My published articles are archived at iSteve.com -- Steve Sailer

April 15, 2009

Breaking News: Your genes didn't evolve to kill you

Genetic reporter Nicholas Wade, who has been on book break, is back with an NY Times front page story "Genes Show Limited Value in Predicting Diseases:

"The era of personal genomic medicine may have to wait. The genetic analysis of common disease is turning out to be a lot more complex than expected.

Since the human genome was decoded in 2003, researchers have been developing a powerful method for comparing the genomes of patients and healthy people, with the hope of pinpointing the DNA changes responsible for common diseases.

This method, called a genomewide association study, has proved technically successful despite many skeptics’ initial doubts. But it has been disappointing in that the kind of genetic variation it detects has turned out to explain surprisingly little of the genetic links to most diseases.

As Matt Ridley has said, no matter what you might think from reading the Health & Science section of your newspaper, your genes didn't evolve in order to kill you. So, this hunt for Killer Genes was always a little dubious, as I've been pointing out all decade.

Instead, your genes evolved to help you survive and reproduce. So, these expensive genome studies have so far proven better at finding the causes of differences in capabilities between individuals and between extended families (a.k.a., racial groups).

Dr. Goldstein argues that the genetic burden of common diseases must be mostly carried by large numbers of rare variants. In this theory, schizophrenia, say, would be caused by combinations of 1,000 rare genetic variants, not of 10 common genetic variants.

This would be bleak news for those who argue that the common variants detected so far, even if they explain only a small percentage of the risk, will nonetheless identify the biological pathways through which a disease emerges, and hence point to drugs that may correct the errant pathways. If hundreds of rare variants are involved in a disease, they may implicate too much of the body’s biochemistry to be useful.

An alternative theory, proposed by Greg Cochran and Paul Ewald in the 1990s is that more diseases are caused by infections than we currently assume. (Here's the 1999 Atlantic Monthly cover story on them.) Of course, genes and germs are not mutually exclusive causes. It could be that, say, you'll only get Disease X if you are both exposed to Germ Y and your immune system lacks Gene Variant Z.

My published articles are archived at iSteve.com -- Steve Sailer

March 23, 2009

Race Reconciled?

From Dienekes's blog, here's the table of contents of the Special Symposium Issue: Race Reconciled of the American Journal of Physical Anthropology. Unfortunately, much of the issue consists of semantic quibbling because academic anthropologists still don't have a workable definition of race (although I do). Several of the abstracts are devoted to beating a dead horse of the white-black-yellow racial model of 1900.
Human DNA sequences: More variation and less race
Jeffrey C. Long, Jie Li, Meghan E. Healy

Interest in genetic diversity within and between human populations as a way to answer questions about race has intensified in light of recent advances in genome technology. The purpose of this article is to apply a method of generalized hierarchical modeling to two DNA data sets. The first data set consists of a small sample of individuals (n = 32 total, from eight populations) who have been fully resequenced for 63 loci that encode a total of 38,534 base pairs. The second data set consists of a large sample of individuals (n = 928 total, from 46 populations) who have been genotyped at 580 loci that encode short tandem repeats. The results are clear and somewhat surprising. We see that populations differ in the amount of diversity that they harbor. The pattern of DNA diversity is one of nested subsets, such that the diversity in non-Sub-Saharan African populations is essentially a subset of the diversity found in Sub-Saharan African populations. The actual pattern of DNA diversity creates some unsettling problems for using race as meaningful genetic categories. For example, the pattern of DNA diversity implies that some populations belong to more than one race (e.g., Europeans), whereas other populations do not belong to any race at all (e.g., Sub-Saharan Africans). As Frank Livingstone noted long ago, the Linnean classification system cannot accommodate this pattern because within the system a population cannot belong to more than one named group within a taxonomic level.

Indeed. Of course, the Linnean classification system can't accommodate much in the natural world, either, because things don't evolve from the top down. That's why I long ago explicitly rejected the top-down Linnean approach to thinking about race in which there's a race for everyone and everyone in his race in favor of the bottom-up genealogical approach of thinking of racial groups as extended families that are partly inbred.
Understanding race and human variation: Why forensic anthropologists are good at identifying race
Stephen Ousley, Richard Jantz, Donna Freid

American forensic anthropologists uncritically accepted the biological race concept from classic physical anthropology and applied it to methods of human identification. Why and how the biological race concept might work in forensic anthropology was contemplated by Sauer (Soc Sci Med 34 [1992] 107-111), who hypothesized that American forensic anthropologists are good at what they do because of a concordance between social race and skeletal morphology in American whites and blacks. However, Sauer also stressed that this concordance did not validate the classic biological race concept of physical anthropology that there are a relatively small number of discrete types of human beings. Results from Howells ... and others using craniometric and molecular data show strong geographic patterning of human variation despite overlap in their distributions. ... In this study, multivariate analyses of craniometric data support Sauer's hypothesis that there are morphological differences between American whites and blacks. We also confirm significant geographic patterning in human variation but also find differences among groups within continents. As a result, if biological races are defined by uniqueness, then there are a very large number of biological races that can be defined, contradicting the classic biological race concept of physical anthropology. Further, our results show that humans can be accurately classified into geographic origin using craniometrics even though there is overlap among groups.

In other words, for many decades, when somebody finds a skeleton buried in a shallow grave in the woods, the cops call in a forensic anthropologist from a university, who examines the bones and reports back something like: "Male, black, age between 20 and 30," which is a big help for the cops.

The point is that despite all that sophomore silliness that cultural anthropologists teach about how race doesn't exist, the forensic anthropologists usually don't have much trouble figuring out which Race box to check on the "Missing Person" ID form. In fact, they are now so good at it, that they can often tell a Swede from a Greek or whatever from the shape of the skull, supposedly "contradicting the classic biological race concept of physical anthropology," (although not my partly inbred extended family model).
Race reconciled?: How biological anthropologists view human variation
Heather J.H. Edgar, Keith L. Hunley

How race becomes biology: Embodiment of social inequality
Clarence C. Gravlee

1918: Three perspectives on race and human variation
Rachel Caspari

Biohistorical approaches to race in the United States: Biological distances among African Americans, European Americans, and their ancestors
Heather J.H. Edgar

Folk taxonomies of race are the categorizations used by people in their everyday judgments concerning the persons around them. As cultural traditions, folk taxonomies may shape gene flow so that it is unequal among groups sharing geography. The history of the United States is one of disparate people being brought together from around the globe, and provides a natural experiment for exploring the relationship between culture and gene flow. The biohistories of African Americans and European Americans were compared to examine whether population histories are shaped by culture when geography and language are shared. Dental morphological data were used to indicate phenotypic similarity, allowing diachronic change through United States history to be considered. Samples represented contemporary and historic African Americans and European Americans and their West African and European ancestral populations (N = 1445). Modified Mahalanobis' D2 and Mean Measure of Divergence statistics examined how biological distances change through time among the samples. Results suggest the social acceptance for mating between descendents of Western Europeans and Eastern and Southern European migrants to the United States produced relatively rapid gene flow between the groups. Although African Americans have been in the United States much longer than most Eastern and Southern Europeans, social barriers have been historically stronger between them and European Americans. These results indicate that gene flow is in part shaped by cultural factors such as folk taxonomies of race, and have implications for understanding contemporary human variation, relationships among prehistoric populations, and forensic anthropology.

In other words, "folk taxonomies" tend to be scientifically accurate.
Estimation and evidence in forensic anthropology: Sex and race
Lyle W. Konigsberg, Bridget F.B. Algee-Hewitt, Dawnie Wolfe Steadman

Forensic anthropology typically uses osteological and/or dental data either to estimate characteristics of unidentified individuals or to serve as evidence in cases where there is a putative identification. In the estimation context, the problem is to describe aspects of an individual that may lead to their eventual identification, whereas in the evidentiary context, the problem is to provide the relative support for the identification. In either context, individual characteristics such as sex and race may be useful. Using a previously published forensic case (Steadman et al. (2006) Am J Phys Anthropol 131:15-26) and a large (N = 3,167) reference sample, we show that the sex of the individual can be reliably estimated using a small set of 11 craniometric variables. .... Similarly, the known "race" of the individual is relatively uninformative in "making" the identification, because the individual was recovered from an area where the 2000 US census provides a very homogenous picture of (self-identified) race. Of interest in this analysis is the fact that the individual, who was recovered from Eastern Iowa, classifies very clearly with ... Easter Islander sample in an analysis with uninformative priors. When the Iowa 2000 Census data on self-reported race are used for informative priors, the individual is clearly identified as American White. This analysis shows the extreme importance of an informative prior in any forensic application.

In other words, there probably aren't a lot of Easter Islanders who wound up in a shallow grave in Eastern Iowa, so forensic anthropology works again!
The global pattern of gene identity variation reveals a history of long-range migrations, bottlenecks, and local mate exchange: Implications for biological race
Keith L. Hunley, Meghan E. Healy, Jeffrey C. Long

Several recent studies have argued that human genetic variation conforms to a model of isolation by distance, whereas others see a predominant role for long-range migrations and bottlenecks. It is unclear whether either of these views fully describes the global pattern of human genetic variation. In this article, we use a coalescent-based simulation approach to compare the pattern of neutral genetic variation predicted by these views to the observed pattern estimated from neutral autosomal microsatellites assayed in 1,032 individuals from 53 globally-distributed populations. We find that neither view predicts every aspect of the observed pattern of variation on its own, but that a combination of the two does. Specifically, we demonstrate that the observed pattern of global gene identity variation is consistent with a history of serial population fissions, bottlenecks and long-range migrations associated with the peopling of major geographic regions, and gene flow between local populations. This history has produced a nested pattern of genetic structure that is inconsistent with the existence of independently evolving biological races. ...

But is consistent with the existence of partly inbred extended families.
How Neandertals inform human variation
Milford H. Wolpoff

Race and global patterns of phenotypic variation
John H. Relethford

Phenotypic traits have been used for centuries for the purpose of racial classification. Developments in quantitative population genetics have allowed global comparison of patterns of phenotypic variation with patterns of variation in classical genetic markers and DNA markers. Human skin color shows a high degree of variation among geographic regions, typical of traits that show extensive natural selection. Even given this high level of geographic differentiation, skin color variation is clinal and is not well described by discrete racial categories. Craniometric traits show a level of among-region differentiation comparable to genetic markers, with high levels of variation within populations as well as a correlation between phenotypic and geographic distance. Craniometric variation is geographically structured, allowing high levels of classification accuracy when comparing crania from different parts of the world. Nonetheless, the boundaries in global variation are not abrupt and do not fit a strict view of the race concept; the number of races and the cutoffs used to define them are arbitrary. The race concept is at best a crude first-order approximation to the geographically structured phenotypic variation in the human species.

In other words, we can now go way beyond the old race concept in detail of tracking origin.

My published articles are archived at iSteve.com -- Steve Sailer

January 30, 2009

James Q. Wilson on "The DNA of Politics"

James Q. Wilson writes in City Journal on The DNA of Politics: Genes shape our beliefs, our values, and even our votes (the picture is of Polish president Lech Kaczyński, right, and former prime minister Jaroslaw Kaczyński, who are identical twins):

Children differ, as any parent of two or more knows. Some babies sleep through the night, others are always awake; some are calm, others are fussy; some walk at an early age, others after a long wait. Scientists have proved that genes are responsible for these early differences. But people assume that as children get older and spend more time under their parents’ influence, the effect of genes declines. They are wrong.

Identical twins tend to get more dissimilar looking as they age due to random wear and tear and a desire to assert one's individuality (e.g., the Kaczyńskis style their hair differently). But they often get more similar in behavior as they spend less time together. For example, say one identical twin is at the 92nd percentile in dominance / leadership while the other one is at the 90th percentile. Growing up together, the second twin will tend to see himself as having a subordinate personality, but when they stop spending all their time together, he will start to realize that other people tend to defer to him and expect him to lead. (Robert A. Heinlein's novel "Time for the Stars" provides a detailed example of this in action.)

For a century or more, we have understood that intelligence is largely inherited, though even today some mistakenly rail against the idea and say that nurture, not nature, is all. Now we know that much of our personality, too, is inherited and that many social attitudes have some degree of genetic basis, including our involvement in crime and some psychiatric illnesses. Some things do result entirely from environmental influences, such as whether you follow the Red Sox or the Yankees (though I suspect that Yankee fans have a genetic defect). But beyond routine tastes, almost everything has some genetic basis. And that includes politics. ...

There are two common ways of reaching this conclusion. One is to compare adopted

children’s traits with those of their biological parents, on the one hand, and with those of their adoptive parents, on the other. If a closer correlation exists with the biological parents’ traits, then we say that the trait is to that degree inherited.

The other method is to compare identical twins’ similarity, with respect to some trait, with the similarity of fraternal twins, or even of two ordinary siblings. Identical twins are genetic duplicates, while fraternal twins share only about half their genes and are no more genetically alike than ordinary siblings are. If identical twins are more alike than fraternal twins, therefore, we conclude that the trait under consideration is to some degree inherited. ...

The gene-driven ideological split that Alford and his colleagues found may, in fact, be an underestimate, because men and women tend to marry people with whom they agree on big issues—assortative mating, as social scientists call it. Assortative mating means that the children of parents who agree on issues will be more likely to share whatever genes influence those beliefs. Thus, even children who are not identical twins will have a larger genetic basis for their views than if their parents married someone with whom they disagreed. Since we measure heritability by subtracting the similarity among fraternal twins from the similarity among identical ones, this difference may neglect genetic influences that already exist on fraternal twins. And if it does, it means that we are underestimating genetic influences on attitudes.

My published articles are archived at iSteve.com -- Steve Sailer

January 10, 2009

Steven Pinker gets his genome tested ...

... and discovers he has the Bald Gene.

In a long article in the New York Times Magazine, "My Genome, My Self," the author of The Blank Slate recounts all that he has learned about himself from having his genome sampled, which turns out to be unsurprisingly modest.

The most prominent finding of behavioral genetics has been summarized by the psychologist Eric Turkheimer: “The nature-nurture debate is over. . . . All human behavioral traits are heritable.” By this he meant that a substantial fraction of the variation among individuals within a culture can be linked to variation in their genes. Whether you measure intelligence or personality, religiosity or political orientation, television watching or cigarette smoking, the outcome is the same. Identical twins (who share all their genes) are more similar than fraternal twins (who share half their genes that vary among people). Biological siblings (who share half those genes too) are more similar than adopted siblings (who share no more genes than do strangers). And identical twins separated at birth and raised in different adoptive homes (who share their genes but not their environments) are uncannily similar.

Behavioral geneticists like Turkheimer are quick to add that many of the differences among people cannot be attributed to their genes.

Identical twins raised apart tend to be almost as similar as identical twins raised together, although part of the reason is that identical twins raised alone don't feel the need to distinguish themselves from their twin by developing something unique about themselves. Horace Grant, the skinny power forward on Michael Jordan's first three championship teams, would probably have become a quick forward if he hadn't grown up playing on youth teams alongside his identical twin Harvey Grant, who became an NBA All-Star shooting forward, while Horace was given the role of rebounding forward.

I know two pairs of adult identical twins, the Brimelows and the Woodhills, and the personal affects vary mildly among the Brimelows and moderately among the Woodhills.
But not all variation in nature arises from balancing selection. The other reason that genetic variation can persist is that rust never sleeps: new mutations creep into the genome faster than natural selection can weed them out. At any given moment, the population is laden with a portfolio of recent mutations, each of whose days are numbered. This Sisyphean struggle between selection and mutation is common with traits that depend on many genes, because there are so many things that can go wrong.

Penke, Denissen and Miller argue that a mutation-selection standoff is the explanation for why we differ in intelligence. Unlike personality, where it takes all kinds to make a world, with intelligence, smarter is simply better, so balancing selection is unlikely.

Is smarter simply better? If it takes, say, bigger brains, the answer isn't terribly clear. Analogously, Intel assumed that faster clockspeed computer CPU chips were simply better for about 15 years. But the struggle to break the 4.0 gigahertz barrier proved overwhelming and so Intel has given up and gone in different directions in recent years, when most chips sold seem to be between 2.0 and 3.0 gigahertz, although performance keeps improving.

Keep in mind that Intel has big advantages over natural selection in getting from one performance peak to another. For example, if Intel decides that its strategy of single chips with ever faster clockspeeds is heading toward a deadend, it can simultaneously start working on an R&D project for double core and quad-core chips with moderate clockspeeds. At first, the new type of CPUs won't be as good as the old type, but it doesn't have to sell the beta versions of the changed design. It can keep making them and throwing them away until the new style chips are as good as the competition's old style chips.

In contrast, natural selection doesn't provide you much of a laboratory in which to putter around while you're working the kinks out of your next model while your factory keeps churning out the satisfactory current model.

Similarly, bigger brains require more food. They make you more likely to tip over and hurt yourself. They require your mother to have a wider pelvis so she won't die in childbirth, which makes her a slower runner.

But intelligence depends on a large network of brain areas, and it thrives in a body that is properly nourished and free of diseases and defects. Many genes are engaged in keeping this system going, and so there are many genes that, when mutated, can make us a little bit stupider.

At the same time there aren’t many mutations that can make us a whole lot smarter. Mutations in general are far more likely to be harmful than helpful, and the large, helpful ones were low-hanging fruit that were picked long ago in our evolutionary history and entrenched in the species. One reason for this can be explained with an analogy inspired by the mathematician Ronald Fisher. A large twist of a focusing knob has some chance of bringing a microscope into better focus when it is far from the best setting. But as the barrel gets closer to the target, smaller and smaller tweaks are needed to bring any further improvement.

The Penke/Denissen/Miller theory, which attributes variation in personality and intelligence to different evolutionary processes, is consistent with what we have learned so far about the genes for those two kinds of traits. The search for I.Q. genes calls to mind the cartoon in which a scientist with a smoldering test tube asks a colleague, “What’s the opposite of Eureka?” Though we know that genes for intelligence must exist, each is likely to be small in effect, found in only a few people, or both. In a recent study of 6,000 children, the gene with the biggest effect accounted for less than one-quarter of an I.Q. point. The quest for genes that underlie major disorders of cognition, like autism and schizophrenia, has been almost as frustrating. Both conditions are highly heritable, yet no one has identified genes that cause either condition across a wide range of people. Perhaps this is what we should expect for a high-maintenance trait like human cognition, which is vulnerable to many mutations.

The hunt for personality genes, though not yet Nobel-worthy, has had better fortunes. Several associations have been found between personality traits and genes that govern the breakdown, recycling or detection of neurotransmitters (the molecules that seep from neuron to neuron) in the brain systems underlying mood and motivation....

But it seems even less plausible to say that more or less of any major psychological trait is "simply better." We may have our subjective preferences, but the major personality traits are likely to be ones on which normal variation doesn't much change average Darwinian fitness over the generations.

Even if personal genomics someday delivers a detailed printout of psychological traits, it will probably not change everything, or even most things. It will give us deeper insight about the biological causes of individuality, and it may narrow the guesswork in assessing individual cases. But the issues about self and society that it brings into focus have always been with us. We have always known that people are liable, to varying degrees, to antisocial temptations and weakness of the will. We have always known that people should be encouraged to develop the parts of themselves that they can (“a man’s reach should exceed his grasp”) but that it’s foolish to expect that anyone can accomplish anything (“a man has got to know his limitations”). And we know that holding people responsible for their behavior will make it more likely that they behave responsibly. “My genes made me do it” is no better an excuse than “We’re depraved on account of we’re deprived.”

Many of the dystopian fears raised by personal genomics are simply out of touch with the complex and probabilistic nature of genes. Forget about the hyperparents who want to implant math genes in their unborn children, the “Gattaca” corporations that scan people’s DNA to assign them to castes, the employers or suitors who hack into your genome to find out what kind of worker or spouse you’d make. Let them try; they’d be wasting their time.

The real-life examples are almost as futile. When the connection between the ACTN3 gene and muscle type was discovered, parents and coaches started swabbing the cheeks of children so they could steer the ones with the fast-twitch variant into sprinting and football. Carl Foster, one of the scientists who uncovered the association, had a better idea: “Just line them up with their classmates for a race and see which ones are the fastest.” Good advice. The test for a gene can identify one of the contributors to a trait. A measurement of the trait itself will identify all of them: the other genes (many or few, discovered or undiscovered, understood or not understood), the way they interact, the effects of the environment and the child’s unique history of developmental quirks.

Well said.

On the other hand, as futile as individual genomics is likely to prove to be relative to current expectations., the Law of Large Numbers suggests that racial genomics is likely to prove more fertile.

My published articles are archived at iSteve.com -- Steve Sailer