Tag Archives: genetics

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.

Side-Effect

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.)

The Fundemental Dogma of All Social Science

Several people have now been kind enough to email me a link to a recent article by Chet Richards, discussing this New York Times piece:

Expressing Our Individuality, the Way E. Coli Do – New York Times
We humans differ from one another in too many ways to count. We are shy and bold, freckled and pale, truckers and hairdressers, Buddhists and Presbyterians. We get cancers in the third grade and live for a century. We have fingerprints.

Even among simple forms of life, like the common bacterium E. coli, genetics only partly determines what any one organism is like. E. coli expresses its individuality in many ways. All the bacilli above are genetically identical, but the shades show differences in the production of proteins that digest lactose.

Scientists have only a rough understanding of how this diversity arises. Some of it stems from the different experiences we have, from our time in the womb on through childhood and into our mature years. These molding influences include things like the books we read and the air we breathe. Our diversity also stems from our genes — the millions of typographical differences between one genome and another.

We put a far bigger premium on nature than nurture when it comes to our individuality. That’s one reason why reproductive cloning inspires so much horror. If genes equal identity, then a person carrying someone else’s DNA has no distinct self.

I think some of the concern against genetics comes from not knowing or accepting the fundemental dogma of all social science: that all variation in human behavior can be explained in terms of independent variables.

There’s some straight genetic effects, straight environmental effects, straight epigenomic effects (such as the Dutch kids was limited working memory at birth, because their mothers were born during famine years), but a lot of stuff is complicated.

So now it’s labeled as “individual variation,” which just means “error.”

It seems that the psychometricians can explain up to 80%+ of variation in IQ in older adults by known factors now. IQ’s been intensively studied for a century, but as more and more is done by pharmaceutical companies because there’s money in knowing what causes those variations, I wouldn’t be surprised if we get up to that level of precision for other things soon.

Human Genetic Variation is Science’s Breakthrough of the Year!

Pennisi, E. (2007). Breakthrough of the year: Human genetic variation. Science, 318(5858), 1842-1843, available online: http://www.sciencemag.org/cgi/content/full/318/5858/1842 (from John Hawks).

We have gone from using genes to contrast us with the chimpanzees, to using genes to contrast us with each other:

The unveiling of the human genome almost 7 years ago cast the first faint light on our complete genetic makeup. Since then, each new genome sequenced and each new individual studied has illuminated our genomic landscape in ever more detail. In 2007, researchers came to appreciate the extent to which our genomes differ from person to person and the implications of this variation for deciphering the genetics of complex diseases and personal traits.

Less than a year ago, the big news was triangulating variation between us and our primate cousins to get a better handle on genetic changes along the evolutionary tree that led to humans. Now, we have moved from asking what in our DNA makes us human to striving to know what in my DNA makes me me.

Techniques that scan for hundreds of thousands of genetic differences at once are linking particular variations to particular traits and diseases in ways not possible before. Efforts to catalog and assess the effects of insertions and deletions in our DNA are showing that these changes are more common than expected and play important roles in how our genomes work–or don’t work. By looking at variations in genes for hair and skin color and in the “speech” gene, we have also gained a better sense of how we are similar to and different from Neandertals.

In one study, geneticists discovered 3600 so-called copy number variants among 95 individuals studied. Quite a few overlapped genes, including some implicated in our individuality–blood type, smell, hearing, taste, and metabolism, for example. Individual genomes differed in size by as many as 9 million bases. This fall, another group performed an extensive analysis using a technique, called paired-end mapping, that can quickly uncover even smaller structural variations.

These differences matter. One survey concluded that in some populations almost 20% of differences in gene activity are due to copy-number variants; SNPs account for the rest. People with high-starch diets–such as in Japan–have extra copies of a gene for a starch-digesting protein compared with members of hunting-gathering societies. By scanning the genomes of autistic and healthy children and their parents for copy-number variation, other geneticists have found that newly appeared DNA alterations pose a risk for autism.

Relatedly: does genetics make Karl Popper obsolete? (Hat-tip to gnxp.)

The End of Private Insurance

Remember my praise of Rudy Giuliani’s federally-based health care plan, especially in contrast to John Edwards and Barack Obama’s backwords company-centered plan?

Giuliani is not just on the side of the angels, he’s on the side of history. At it becomes cheaper and cheaper to sequence a person’s genome, we will either face a situation where insurance companies only provide insurance to people they know will be healthy or, atlernatively, only people who believe they will be sick will buy insurance. (In other words, just like now, or worse.)

The solution, however it comes, will have to be risk-pooling at a national level. Giualini’s plan starts us down that road. Edwards and Obama, by contrast, offer only a tired repeat of the old industrial state.