Tag Archives: genetics

Flesh and Blood, Genetic and Non-Genetic Influences

Three Cheers for Genetic Discrimination!

On facebook, Niles Bliss made some comments about genetics and human behavior that are worth describing. He phrased the same belief in a number of different ways, but this one line sums up a good deal of Niles’ philosophy

It is wrong to treat one group differently due to genetic factors.

Of course, this comment is absurd on two different levels.

Whenever people discuss genetics on facebook, it’s a good bet that they’re discussing race, sex, vaccination, or homosexuality. Another comment by Niles makes it clear this is once again the case [emphasis mine]:

Denying someone the ability to take part in an institution, i.e. marriage, because of a
genetic factor
, i.e. enjoying sodomy (or the females only equivalent), is morally wrong
. The POA vs. Marriage is not the issue. You can keep it. The issue is being treated as a full-fledged member of the species instead of some sort of aberrant embarrassment. Neither polygamy nor Mormonism/Islamism is determined genetically, so there is not the same moral consideration. I do not believe in cultural relativism, and if your religion must have multiple wives, go to a government that is cool with it.

To break this down, Niles is asserting two common, but mistaken, ideas

1. Some widespread variant human behaviors are “determined genetically”
2. It is ethically wrong to discriminate against genetically-driven traits.

“Determined Genetically” Means That You Can’t Avoid The Expression of the Trait Without Killing, Dismembering, or Lobotomizing the Subject

When people say “determined genetically,” they mean that 100% of variation of a trait within a population is caused exclusively by genes. There are some diseases that operate like this, but not many. Certainly I am not aware of any complex societal traits that are “determined genetically.”

Given the influence that nutrition has in early development, I am not even sure that something as “simple” as earlobe-shape is “determined genetically.”

Non-genetic factors in our development include social environment, nutrition, epigenetic load, and pathogenic load.

Discriminating Against People For Genetically-Shaped Traits Is Both Fun, Easy, and Morally Virtuous

Here are a list of some traits with large “genetic components,” that is, given similar environments, most of the variation in these traits by age 30 or so will be the result of variation in DNA

1. Political Orientation
2. Religious Ferver
3. General Intelligence
4. Creativity
5. Future Time Orientation
6. Openness to New Experience
7. Conscientiousness
8. Extraversion
9. Agreeableness
10. Neuroticism
11. Some forms of Schizophrenia / Psychopathology
12. Skin Hue
13. Height
14. Build of musculature
15. Fatty tissue distribution

The only way you are having any fun in your life if you are not discriminating on any of these traits is if you consider the lack of control you now have over your life as “fun.”

(I am exclude homosexuality here because I am unaware of a study showing that > 50% of variation in expression of that trait by age 30 is predictable based on knowledge of blood relatives. I did not, however, research this before writing this post, as my whole point is that not discriminating based on genetic tendencies is ridiculous)

Discrimination Is Right? Wrong? Something Else?

“Discrimination” means treating different things different, and different people differently, based on features that are meaningful.

Many traits with large “genetic components” are meaningful in our lives. Tendency to crime, beauty, personality, political orientation, skin hue, fervor, etc., all matter to us in meaningful ways. Traits without the same obvious genetic component — which political party you belong to, which Church you worship at, perhaps even your sexual orientation — also matter.

Human beings are not disembodied ghosts. Nor are we soulless corpses. We have bodies. We are made of flesh and blood and spirit, clay and the breathe of life.

Some Notes on the Development of Our Species

In recent days there has been a bru-haha in the conservative blogosphere as a result of Rich Lowry dismissing John Derbyshire from his position as a writer for National Review Online. The occasion was an controversial article on race relations written by Mr. Derbyshire.

The fight is basically political. Rich Lowry is associated with the Catholic, classically-establishment Establishment, wing of the conservative moment. John Derbyshire is associated with the atheist, scientifically-educated, insurgent wing of the conservative movement.

I want to talk about this in some upcoming posts, but as the occasion for the fight relates to the science of human origins, I thought I would share a brief history of our species. Much is tentative and subject to possible revision, but this should provide some context to the discussion. (As both Catholics and atheists tend to view Creationism derisively, this should not be controversial, either).

Around six million years ago, the ancestors of human beings, chimpanzees, and bonobos (“dwarf chimps”) were part of the same ancestral population. As the modern populations feature behaviors such as murder, suicide, warfare, terrorism, bisexuality, care for the injured, tool making, and purposeful deception, it seems sensible that the ancient population from which humans, chimps, and bonobos derive did, too.

The three populations began to diverge after an environmental catastrophe associated with a shift in the Congo River. This catastrophe also impacted gorillas. Chimps evolved in an area where they were in competition with gorillas. They became the most interpersonally vicious of the populations. Bonobos evolved in a forested environment without gorillas. They became the most interpersonally peaceful. Our ancestors seem to have left the forest to compete with wild hogs in the woodlands.

As the old saying goes, “Dogs look up to us. Cats look down on us. Only pigs treat us as equals.”

While our ancestral population remained small in absolute terms, their ability to move in woodlands allowed them to spread out over much of Africa.

Humans slowly evolved. The general trend appears to have been an increase in absolute size (important for woodland competition), a decrease in sexual dimorphism (a not-fully-understood development that may have been cause by an increase willingness of human “betas” to murder “alphas” for perceived unjust behavior), and a darkening of skin color (chimps and bonobos both have white skin). These trends continued until all human populations were larger than bonobo or chimp populations, all human populations featured a smaller relative size difference between males and females than any bonobo or chimp population, and all human populations had brown-to-black skin tone.

Ancestral humans left Africa in multiple waves. Different waves were adapted to different conditions. Finally, hundreds of thousands of years ago, all of Eurasia was patrolled by human populations. Three important ones were Neanderthals (based in Europe and west Eurasia), “Peking Men,” (based in Asia), and Anatomically Modern Humans (based in Africa and the Near East). These populations overlapped in the way that other megafauna do.

All modern populations derive from some combination of these ancient populations. All modern populations appear to be primarily descended from Anatomically Modern Humans. Europeans contain a measurable degree of Neanderthal admixture. Asian populations contains measurable degrees of Peking Men admixture. African populations appear to be exclusively descended from Anatomically Modern Humans.

Some time after the mixture-and-replacement of other populations with Anatomically Modern Humans and their hybrid descendents, Behaviorally Modern Humans emerged in the Near East. The oldest cities, such as Jericho, are older than agriculture. From this is seems clear that the major advantage of Behaviorally Modern Humans against ancient populations was the ability to live in large coordinated groups, or “eusociality.” Behaviorally Modern Humans appear to be about as eusocial as ants or bees.

The eusociality of Behaviorally Modern Humans allowed them to develop caste systems of leaders, warriors, and slaves, just like other eusocial animals. With the advent of slavery farming became possible, and with the advent of a distinct military caste (that is, the first gradient of modern warfare) military campaigns became possible.

Behaviorally Modern Humans created a new form of war in which a military caste, led by a leadership caste and fed by a farmer caste, would invade neighboring communities, exterminate males and children, and rape and impregnate females. This led to rapid hybridization and spread, such that Behaviorally Modern Humans soon replaced nearly all Anatomically Modern Human communities.

Resource competition between Behaviorally Modern Human societies led to an increase in the rate of human evolution. Humans have evolved more in the past 10,000 years than in any other 10,000 year period of our species.

Traits in which there is a ‘correct’ number of expressions are soon fixed in a population. Humans have 2 eyes, 1 nose, and 10 fingers, for example.Traits which are generally unimportant (or are basically social traits which exist in some equilibrium) follow a normal distribution. General intelligence, time-orientation, and the five factors of personality follow normal distributions. From this we can conclude that for most of our accelerated period of evolution, there was no ‘right’ amount of these traits to have.

These traits are both inherited and culturally transmitted. It makes no sense to talk of ‘nature vs. nurture.’ Our cultural environment determines how these inherited traits are expressed. A better phrase might be “nature via nurture.”

Human populations differ in terms of the averages in these traits. For instance, newborn (1 day old) Chinese are more afraid of strangers (more “introverted”) than newborn Kenyans. Likewise, there is variation within these populations. There is more variation within populations than between population. There are, for example, a very many extroverted Chinese, and a very many introverted Kenyans. People talk of differences in “averages,” but this is a misleading way to talk. The difference between the 50th percentile and the 53rd percentile in extroversion, for example, is likely to be barely noticeable.

Rather, average differences matter in the extremes. If you take 1,000 random Kenyans and 1,000 random Chinese, and you take the top 20 of that group of 2,000 in terms of extroversion, that top 20 will be overwhelmingly Kenyan. Likewise, if you take the top 20 in terms of introversion, that 20 will be overwhelmingly Chinese.

Approximately 2,000 years ago, the leadership caste of China undertook a massive reorganization of society to reduce the military caste to peony and to establish a “Civil Government.” This was the greatest cultural revolution in human affairs since the invention of agricultural slavery 8,000 years previously. Through a trial-and-error process, the Chinese leadership class eliminated the centers of powers of the military caste and replaced it with a standing civil service supported by secured property owners. While the new system naturally attracted barbarian predators, the cultural transformation proved imperious to counter-revolution. Within a millennial the system was being tentatively mimicked from London to Edo.

The emergence of Behaviorally Modern Humans led to an unprecedented acceleration in human evolution. The creation of Civil Government had a likewise world-altering impacted. Society under the Civil Government was strongly downwardly-mobile. It was nearly impossible to improve one’s lot in society, but very easy to make foolish decisions that reduced one to rags. Every generation the foolish would lose property, and poor would starve to death, and the healthy children of the survivors acquired the survival traits of higher general intelligence and longer time orientation.

The increase in the concentration of wealth enabled by Civil Government allowed the new societies to invest massive resources in exploration efforts, in search of further resources to exploit and extract. World-historical empires such as Britain, France, Spain, the Ottoman Empire, and the Great Ming wrecked destruction on their backwards cousins. The mobilizations for war of these societies, and the increase efficiencies of Civil Government, led to greater and greater demand for labor (that is, surplus of capital). The Great Ming solved this by creating the most effective sanitation system in the world, allowing organic population increase to meet its needs. The Ottoman Empire solved this issue through enslaving neighboring populations. The Western European Civil Governments (which had missed out on the economies of scale that come from creating a secure geographic core) established a “triangle trade” that relied on tenuous geographic centers in Europe, Africa, and the Americas to supply their capital, labor, and natural resources requirements, respectively.

The geographically diverse, scattershot nature of the European empires meant that they (unlike Near Eastern, central Eurasian, or East Asian societies) experienced regular sociogenetic shocks. The Western European Civil Governments found that their African client states controlled land that was inhospitable to Europeans, largely because of genetic adaptations against malaria possessed by West Africans but not Europeans. Likewise, the living conditions established by the Central Governments in the New World proved inhospitable to the native populations there. Likewise, the Civil Governments encouraged different groups to settle in different areas, such that (for example) the Yankee core of the future United States was settled by English who had experienced more rapid downward mobility than the Scotch-Irish who settled the future southeastern united States.

This all goes to say that the New World may exhibit the most human diversity on the planet, close only to Africa. The more settled and stable populations of Eurasia, by contrast, are comparatively monocultural with limited genetic diversity.

Americans use the term “race relations” to refer to the cultural and genetic human diversity in their midst. Unsurprisingly, both the cultural and genetic pathways of the populations that settled in the United States remain relevant, often in unexpected ways. Anyone with a naive understanding of psychometric methods would expect East Asians and Western Europeans to have a disproportionate share of wealth in the United States, and of course they do. Who could have expected, however, that much of African-American culture would be a hybrid of west Africa with the highlands of Scotland? Talk of historical contingency!

It is with this context that John Derbyshire wrote his article on Taki Magazine. Every point Derbyshire makes is predictable if one assumes he is writing of a population that did not experience rapid downward mobility in historic times that spent centuries under the leadership of a different population with a different appearence but a similar pre-Civil Government ethic.

To put it slightly less obtusely, John Derbyshire wrote an article describing personal safety in the presence of the descendents of West Africans whose ancestors were controlled by the Scotch-Irish.

To put it even more plainly, Derbyshire wrote about blacks and violence.

And that is why he is no longer employed.

Genetic Map of East Asia

This genetic map of East Asia appears to be formed by running a Principal Component Analysis (PCA), taking the two largest components, using those as horizontal and vertical axes, and then rotating them. PCA is one of many techniques in a href=”http://www.statmethods.net/advstats/factor.html”>multivariate statistics that allow explortation of ‘unknown unknowns’ — what variables did you not measures, but which secretly are influencing the variables you did measure?

The genetic map of Asia looks even more like a ‘map than the Genetic Map of Europe that was featured at Catholicgauze, gnxp, and here earlier. Japanese and Koreans (two historically closed-off populations) look like ‘islands.’ Likewise, ‘Chinese Americans’ are placed on this map somewhere around Taiwan, which makes sense given that the old Chinese population in America comes largely from the Cantonese region of China.

Just as genetics is helping make geography mroe quantitative and more meaningful, quantatitive analysis is also transforming history from a collection of stories to a real social science. Razib’s post on North African and Jewish influences in the Spanish population is, hopefully, an example of history is becoming.

Group Differences in the News

Evolution has, is, and will continue to go on all around some. Some recent blog posts about group differences, and how selection effects them.

AIDS resistance, personality, politics, disease-risk, and intelligence are all heritable, thus the common thread of these psots.

Gene Expression: Notes on Sewall Wright: the Adaptive Landscape

Apparently inspired by Razib’s epic post on faith and historical dynamics, DavidB over at gnxp writes his own epic post on fitness peaks. Again, there is too much to summarize, but this analogy to why there may be many (or none) alien civilizations should catch some interest:

Gene Expression: Notes on Sewall Wright: the Adaptive Landscape
In his original 1932 presentation Wright used a simple probabilistic argument for the existence of numerous peaks. The number of possible genotypes is vast, so even if only a tiny proportion of them are local optima, the number of local optima would still be very large: ‘With something like 10^1000 possibilities it may be taken as certain that there will be an enormous number of widely separated harmonious combinations. The chance that a random combination is as adaptive as those characteristic of the species may be as low as 10^-100 and still leave room for 10^800 separate peaks….(ESP p.163)’.

This is a dubious argument. It may be compared to a common argument for the existence of intelligent life elsewhere in the universe. There are around 10,000 billion billion stars in the universe, so even if the proportion of stars with planets supporting intelligent life is tiny – say, 1 in 10,000 billion – there would still be an enormous number of such stars. But consider the following counter-argument. It is plausible that the emergence and survival of intelligent life requires a moderately large number of conditions – say, at least 100 – to be met. It is also plausible that these conditions are largely independent, and individually quite improbable – say, with a probability of only 1 in 100. But with these assumptions, the probability that all of the necessary conditions are met in any given case is less than 1 in 1/100^100. This is vastly less than 1 in 10,000 billion billion, so rather than expecting there to be a large number of stars with planets supporting intelligent life, it would be a miracle if there are any at all. In reality, neither argument goes much further than establishing the bare possibility of the conclusion. Similarly, in the case of selective peaks, the sheer number of possible genotypes is in itself not a strong argument for the existence, rather than the bare possibility, of numerous different peaks.

Razib’s and DavidB’s posts are higher on both velocity and depth than most journal articles, though I guess one could say they may far away from the ‘fitness peak’ of blog posts!

The Clusters of the Races of Europe

Catholigauze blogged the last genetic map of Europe and numerous friends asked me for my thoughts on it, so I thought I would be ahead of the curve and post the latest version of how they can place your ancestry by your DNA (hat-tip to gnxp):

Baby boomers — and those taught by them — have long since digested the conventional wisdom that there are no “races,” that ancestral populations exist only in social construction, and that we all come with the same abilities when we are born (or at least, that different “races” all come with the same average abilities and same variation in thsoe abilities, statistically). Of course, this is not true. Not only are we able to identify this race from that, this population from that, we are zooming in farther and farther in the data: what valley did your ancestors come from? We may soon be able to tell you.

Exposing the fallacy of equal-ability–when-treated-equally-at-birth is a grave challenge, both to those Marxists who insist on a “blank slate” and to those conservatives who insist on laissez faire policies because everyone can just pull themselves up by their bootstraps. But this political debate, finally, is being impacted by the latest in scientific knowledge.


Razib at gnxp uses the word “pleiotropy,” but you can focus on its result: “side-effect.” It appears that skin and hair color evolved later than the founding of the major continental racial populations. More on that is availabl in The Blank Slate (see also my notes). However, this ironically implies that skin-color-differences may not be skin deep. Because only a few big mutations seem to cause the change in color that we see, which iplies there was strong selection in favor of light skin color, there may be side effects of this.

Gene Expression: Beware the dark-eyed
The fact that blondes have more fear and redheads feel more pain might make some more sense. Skin color seems to have gotten lighter over the past 5-20 thousand years across northern Eurasia by substitutions and changes in frequency on a few loci of large effect. Evolutionarily this predicts that pleiotropy will product side effect phenotypes before modifier genes can arise to mask the deleterious byproducts of said evolution.

More research still needs to be done, but the great strides that genetic research is making keeps impressing me.

If knowledge is the heart of quality control, we are well on our way to a population with quality.

The New Core sets the New Rules, on Designer Babies

Today’s food for thought:

Many discussions on designer babies — that form of eugnics which operates by selecting attributes for the next generation of your biological family — seem to assume that the culture and moral compass of the United States and Europe will matter much. America and Europe are comfortable, labor-poor, capital-rich societies, and can rely on a large and generous government to protect them. Economic growth and welfare policies mean that few Americans or Europeans will ever know true poverty, and while the poor are effectively punished in numerous ways (such as having to live with a violent underlcass), these concerns are politely ignored and the poor are criticized for raising them.

The rising countries of the New Core are not so lucky. Things which are matter of convenience for us are matters of survival for them. Terrorism, high energy prices, and similar things inconvenience us but threaten to relegate rising nations like India and China back into poverty and neglect.

So India and China are hungry. They are changing the game. And that applies to designer babies, too.

In America, we take education for granted to such an extent that only rare politicians like George Bush and Ted Kennedy take the political heat for trying to fix it. We do not have the National Exams of China, or the Indian Institutes of Technology, that aggressively weed out all but the best students. In the United States, for most students, the difference between attending a school in the top 5, top 10, and top 50 is pretty negligible — your success will largely be a result of your ability and effort. A 2% of 10% better chance of gtting a good grade or doing well in high school simply isn’t a concern of parents in Europe or the United States.

Those things do matter is in India and China.

So when genetic screening for positive traits hits the $10,000 range, expect a large Indian and Chinese middle class to begin selecting for socially desirable traits, such as dilligence, future-orientation, intelligence, height, fair skin, and so on.

All this chatter about Gattaca won’t matter much. One might as well have tried to turn back the Industrialization of the United States by citing “And did those feet in ancient time.”

Hungry nations care about success for more than sentimentality.

Sentimentality may a drug for the rich and the poor, but not those among the poor who desire to be rich.

The Genetics of Human Social Behavior, and Its Implications for the Peace

This is very cool. DRD47R is associated not just with high functioning ADD, novelty seeking, and distance from the Yellow River of China (for mongoloid populations), but also Friendship, Politics, and Food.

From James Fowler’s “Friendships Moderate an Association Between the DRD4 Gene and Political Ideology” (pdf):

Studies of identical and fraternal twins suggest that political ideology has a heritable component (Alford, Funk, and Hibbing 2005; Hatemi et al. 2007), but no specific gene associated with political ideology has so far been identified. Using data from the National Longitudinal Study of Adolescent Health, we investigate the moderating influence of friendships on the contribution of the 7R allele of the DRD4 gene to liberal political ideology. The number of self-nominated friendships in adolescence moderates the influence of the gene on political ideology; the more friends nominated, the stronger the liberal ideological identification of the respondent in early adulthood. This is the first study to elaborate a specific gene-environment interaction that contributes to ideological self-identification.

And “Dopamine receptor genetic polymorphisms and body composition in undernourished pastoralists: An exploration of nutrition indices among nomadic and recently settled Ariaal men of northern Kenya” (hat-tip to gnxp and Scientific Blogging):

While those with the DRD4/7R allele were better nourished in the nomadic population, they were less well-nourished in the settled population. Although the effects of different versions of dopamine genes have already been studied in industrialized countries, very little research has been carried out in non-industrial, subsistence environments like the areas where the Ariaal live, despite the fact that such environments may be more similar to the environments where much of human genetic evolution took place.

The first time I encountered research like this, my first reaction was “This can be used to help secure the peace.” Our knowledge is still early and piecemeal to turn this genetic research into real-world battlespace advantages, but I don’t think we are too far away. Imagine, for instance, if an occupying force could quickly screen the population using genetic knowledge, prevently detaining those most likely to cause trouble, thus protecting the general civilian population and potential terrorists from harm?

(While certainly those who oppose military solutions would object to this, an occupying power could easily argue that they are required to do such screenings once they are feasible, under the doctrine of responsibility to protect.)

Cognitive Function and our Genetic Code

Courtesy of Razib

Developing Intelligence : 99% Genetic? Individual Differences in Executive Function Are Almost Perfectly Heritable
Your ability to control thought and behavior relative to your peers – a set of capacities known as “executive functions” – is almost entirely genetic in origin, according to a newly in-press paper from Friedman et al. Over 560 twins completed tests to measure fundamental components of these executive functions, and the results were analyzed in terms of how similar identical twins performed to one another relative to fraternal twins (all twins in the study were reared together). Astonishingly, the results show that the variance common to all executive functions is correlated roughly twice as much between identical twins as between fraternal twins, and that individual variance in executive function falls directly in line with what would be expected from a perfectly heritable trait.

Furthermore, Friedman et al. integrated measures of general intelligence (“g”, estimated through the WAIS IQ test) and perceptual speed (essentially the speed with which subjects can complete very simple tasks) to show that the genetic contribution to executive function is not completely explained by genetic contributions to those more commonly-studied abilities. This is consistent with previous work showing that IQ is only moderately heritable (with 50-70% of variance explained due to genetic factors, far short of the 99% explained here).

99.9% is huge. The only study I can remember that came close is one of the studies that found working memory is 96% correlated with g. The conclusion that study and others received is that working memory was g. If the 99.9% number holds up for this study, then it will be accurate to say that executive function is genetically determined.

Fun stuff, and doubtless some serious money here for the pharmaceutical industry. True social equality looks like it will have to wait until gene therapy (Eugenics While You Wait(TM)) becomes common.